Case studies on free drying shrinkage test sensitivity and on carbonation rate of mortar with photocatalytics

A number of recent studies have examined different methods for preventing concrete distresses and limiting structural failures in order to reduce construction repair costs. Common distresses are cracking, scaling, delamination, and spalling. The causes of these concrete distresses can be from a wide variety of mechanisms, two of which are shrinkage and carbonation, which will be investigated in separate case studies. A common influence on both shrinkage and carbonation is the environmental exposure effect. In one case study, shrinkage was investigated to find out the effects of different environmental conditions (specific relative humidity RH and temperatures) and specimen size (or surface area exposed to the environment). The free drying shrinkage based on ASTM C157 was measured for two mortar mixtures but with different storage conditions (ranging from 4.5% RH to 99.9% RH and 11.2 °C to 25.4 °C on average) from 12 hours to 56 days. Three to four replicates of these mortar samples in each storing environment were also tested at each sample size of 1” prisms (1”Ã-1” Ã-11.25”), 2” prisms (2”Ã-2” Ã-11.25”), and 3” prisms (3”Ã-3” Ã-11.25”). The results verified that high humidity reduces shrinkage. It was also found that 3” prisms (surface area to volume ratio of 1.51) reduce shrinkage sensitivity among any storage environment. In another case study, carbonation was investigated to find out if the rate and depth were influenced by the presence of a photocatalytic material TiO2. A plain mortar mixture was compared to the same mortar with the TiO2 sprayed on the sample surface, and compared to the same mortar with 1% cement replacement of TiO2 particles. All samples were exposed to the same outdoor environment for up to 100 days. A scanning electron microscope and energy dispersive spectroscopy was used to verify the interior TiO2 content in the mortar. Thermo-gravimetric analysis and mass spectrometry were used to determine the amount of carbonation from samples taken at different ages and different depths. Result indicated mortar containing photocatalytic materials either embedded or sprayed on the surface have more carbonation at later ages and at the surface.

CASE STUDIES ON FREE DRYING SHRINKAGE TEST SENSITIVITY AND ON CARBONATION RATE OF MORTAR WITH PHOTOCATALYTICS by Lingkun Li A thesis submitted to the faculty of The University of Utah in partial fulfillment of the requirements for the degree of Master of Science Department of Civil and Environmental Engineering The University of Utah May 2017 Copyright © Lingkun Li 2017 All Rights Reserved The University of Utah Graduate School STATEMENT OF THESIS APPROVAL Lingkun Li The thesis of has been approved by the following supervisory committee members: Amanda Bordelon , Chair 10/07/2016 Date Approved Pedro Romero , Member 01/19/2017 Date Approved Geoffrey Silcox , Member 01/18/2017 Date Approved and by Michael E. Barber the Department/College/School of , Chair/Dean of Civil and Environmental Engineering and by David B. Kieda, Dean of The Graduate School. ABSTRACT A number of recent studies have examined different methods for preventing concrete distresses and limiting structural failures in order to reduce construction repair costs. Common distresses are cracking, scaling, delamination, and spalling. The causes of these concrete distresses can be from a wide variety of mechanisms, two of which are shrinkage and carbonation, which will be investigated in separate case studies. A common influence on both shrinkage and carbonation is the environmental exposure effect. In one case study, shrinkage was investigated to find out the effects of different environmental conditions (specific relative humidity RH and temperatures) and specimen size (or surface area exposed to the environment). The free drying shrinkage based on ASTM C157 was measured for two mortar mixtures but with different storage conditions (ranging from 4.5% RH to 99.9% RH and 11.2 °C to 25.4 °C on average) from 12 hours to 56 days. Three to four replicates of these mortar samples in each storing environment were also tested at each sample size of 1" prisms (1"×1" ×11.25"), 2" prisms (2"×2" ×11.25"), and 3" prisms (3"×3" ×11.25"). The results verified that high humidity reduces shrinkage. It was also found that 3" prisms (surface area to volume ratio of 1.51) reduce shrinkage sensitivity among any storage environment. In another case study, carbonation was investigated to find out if the rate and depth were influenced by the presence of a photocatalytic material TiO2. A plain mortar mixture was compared to the same mortar with the TiO2 sprayed on the sample surface, and compared to the same mortar with 1% cement replacement of TiO2 particles. All samples were exposed to the same outdoor environment for up to 100 days. A scanning electron microscope and energy dispersive spectroscopy was used to verify the interior TiO2 content in the mortar. Thermogravimetric analysis and mass spectrometry were used to determine the amount of carbonation from samples taken at different ages and different depths. Result indicated mortar containing photocatalytic materials either embedded or sprayed on the surface have more carbonation at later ages and at the surface. iv TABLE OF CONTENTS ABSTRACT....................................................................................................................... iii ACKNOWLEDGEMENTS .............................................................................................. vii Chapters 1 INTRODUCTION ........................................................................................................... 1 1.1 Concrete Properties and Distresses ........................................................................... 1 1.2 Shrinkage .................................................................................................................. 2 1.3 Carbonation ............................................................................................................... 2 1.4 Objectives ................................................................................................................. 3 1.5 Scopes ....................................................................................................................... 4 1.6 Techniques ................................................................................................................ 4 1.6.1 Standard Test Procedures Used or Modified in Studies .................................... 4 1.6.2 Statistics Used in Shrinkage Study .................................................................... 5 2 FREE SHRINKAGE ON CEMENT MORTARS ........................................................... 7 2.1 Shrinkage Types and Mechanism ............................................................................. 7 2.2 Shrinkage Magnitude Prediction............................................................................... 8 2.3 Shrinkage Prediction and Moisture Diffusion .......................................................... 9 2.4 Methodology ........................................................................................................... 12 2.4.1 ASTM C157 Modification ............................................................................... 12 2.4.2 Storing Conditions ........................................................................................... 13 2.4.3 Materials, Mix Design, and Specimens ........................................................... 15 2.4.4 Measurements .................................................................................................. 16 2.5 Results ..................................................................................................................... 18 2.5.1 Overall Analysis............................................................................................... 18 2.5.2 Average and Daily Fluctuation in Humidity Influence on Shrinkage ............. 20 2.5.3 Size Effects on Shrinkage ................................................................................ 21 2.5.4 Shrinkage of Mortars with Sand-Cement Proportioning ................................. 21 2.5.5 Shrinkage Predictions ...................................................................................... 22 2.6 Summary and Findings ........................................................................................... 25 3 CARBONATION .......................................................................................................... 45 3.1 Carbonation Reaction.............................................................................................. 46 3.2 TiO2 Properties........................................................................................................ 46 3.3 Methodology and Materials .................................................................................... 47 3.4 Experiments ............................................................................................................ 49 3.4.1 Verifying TiO2 Content.................................................................................... 49 3.4.2 Carbonation Estimation ................................................................................... 50 3.5 Results ..................................................................................................................... 52 3.5.1 Chemistry Composition ................................................................................... 52 3.5.2 Carbonation Quantity ....................................................................................... 52 3.6 Summary and Findings ........................................................................................... 53 4 CONCLUSION .............................................................................................................. 62 4.1 Conclusions and Suggestions.................................................................................. 62 4.2 Further Studies ........................................................................................................ 63 Appendices A TEMPERATURE, %RH, AND DAILY FLUCTUATION FIGURES ........................ 65 B OVEN DRY (OD) BATCH AMOUNT ........................................................................ 74 C TESTING DATES ........................................................................................................ 75 D SHRINKAGE RELATIVE TO HUMIDITY CHAMBER ........................................... 76 E SHRINKAGE AND WEIGHT CHANGE FIGURES .................................................. 77 F SHRINKAGE PREDICTION PER ACI COMMITTEE 209 ....................................... 87 G SHRINKAGE PREDICTION PER MOON AND WEISS........................................... 96 H SEM/EDS SAMPLE PREPARATION ...................................................................... 107 I RAW EDS NUMBER .................................................................................................. 109 J RAW TGA ................................................................................................................... 113 REFERENCES ............................................................................................................... 137 vi ACKNOWLEDGEMENTS The research funding came from the Mountain Plains Consortium and Dr. Bordelon's startup funds. I want to express my thanks for the SEM training, the equipment, and the chance they gave to me to chase my dream. I could not have finished my master's thesis without all those who helped me. Firstly, I want to show my sincere thanks to my advisor, Dr. Amanda Bordelon. Her knowledge, friendship, and guidance have always shown me the right way to conduct my research. Thanks also to my committee members, Dr. Pedro Romero and Dr. Geoff Silcox; without their help, I could not have finished my research. Mark Bryant always helped me set up all the equipment in the laboratory. Dr. Brian Van Devener and Paulo Perez from University of Utah Nanofab helped me with the SEM/EDS analysis. Dr. Joel S. Miller and Eric Campbell from the Chemistry Department provided me help with the TGA analysis in my research. The UATAQ lab provided me the CO2 data. Most importantly, I want to say thank you to all my family and my girlfriend, Yurou Gan; without them, I could be lost. They gave me strength and always encouraged me. Besides, I express my thanks to my colleagues, Dillon Li, Jafar Allahham, Siddharth Rayaprolu, James Holt, Martin Dinsmore, and Catalina Arboleda. They gave me the inspiration in my research. My friend, Chenyu Cui, from Ireland, helped me mix concrete. CHAPTER 1 INTRODUCTION 1.1 Concrete Properties and Distresses As a common construction material, concrete has been widely used in residential and commercial structures, freeways, and bridges as concrete can have high durability, a good workability, and a desired strength. The popularity of concrete, however, does not mean this material is without limitations. In fact, concrete distresses happen all of the time, which could lead to higher cost to repair or even structures' failure. The common distresses according to ACI 201.1R-08 from the American Concrete Institute (ACI) are cracking and deterioration such as chalking, pitting, scaling, deformation, etc. (ACI Committee 201 2008). According to the Portland Cement Association (PCA), there are some factors that could influence concrete distress: chemical attack, alkali-aggregate reactivity, heat, overloads, volume changes, etc. (PCA 2002). PCA has also noted that shrinkage due to water loss and carbonation are two major factors, which could be classified under volume change and corrosion of embedded metals distresses. 2 1.2 Shrinkage Drying shrinkage is a common phenomenon that happens over time in concrete after hardening, and is caused by water loss. Drying shrinkage leads to concrete cracking, when base friction or restraint resists volume change. Restraint to concrete shrinkage is considered the most common cause of concrete cracking (PCA 2002). Studies on concrete drying shrinkage date back to the 1920s, when an article focused on the drying behaviors of clays and shales (McClenahan and Rigling 1929). Nowadays, investigations focus more on the shrinkage of concrete due to the addition of admixtures (Domingo-Cabo et al. 2009; Duan et al. 2016; Güneyisi et al. 2014; Yoo et al. 2015). For concrete and mortar, shrinkage behaviors influenced by curing, ambient environmental conditions, exposed surface area, mixture components, and proportions are all expected to contribute to the crack formation and crack widths. 1.3 Carbonation Carbonation is the chemical reaction resulting when CO2 in the air and Ca(OH)2 in hydrated concrete gradually react to form CaCO3. The carbonation reaction rate mainly depends on the concentration of CO2, the permeability of concrete, reaction temperature, ambient humidity, chemistry of the cement, age of the concrete, and existence of previous cracks (Ashraf 2016). This rate is nonlinear and increases with the increase of exposure time. Additionally, there are several other factors that could increase carbonation rate, including increased CO2 concentration, an environmental RH range of 50% to 75%, moisture content in concrete, high water/cement ratio, low cement content, etc. (PCA 2002). 3 By adding chemicals or chemical admixtures, concrete properties could be adjusted, or an additive like titanium dioxide may influence the environment. For example, water reducers are used to reduce the water amount that is needed for a given workability, shrinkage-reducing chemicals are used to reduce concrete shrinkage, etc. An example of chemicals that impact the environment is titanium dioxide. Titanium dioxide is a photocatalytic material that could be applied in concrete to clean NOx gas, a major component of air pollutions, in the air. Since concrete is widely used in constructions and pavements, TiO2 particles have been increasingly applied to concrete or the concrete surface to clean the air (Ballari and Brouwers 2013; Chen and Poon 2009; Diamanti et al. 2013; Shen et al. 2012). Recent studies have found concrete embedded with TiO2 does not clean the air beyond a 4-month to 1-year period of exposure (Bogutyn et al. 2015). Analysis of these inefficient TiO2 applications revealed that carbonation on the surface blocked the reaction with NOx (Bogutyn et al. 2015; Hanson 2014). 1.4 Objectives Two specific cases were investigated in this study regarding concrete drying shrinkage and carbonation. In Chapter 2, the sensitivity of the free shrinkage test method is evaluated based on different average and daily fluctuation magnitudes of relative humidity during air drying, and different surface-to-volume ratios, to give recommendations to future laboratory testing conditions. In Chapter 3, it is hypothesized that mortars containing TiO2 particles will have more carbonation at later ages and greater depths than plain mortar. 4 1.5 Scopes In Chapter 2 on free shrinkage sensitivity, a modified ASTM C157 free shrinkage test method was performed to evaluate the air-storage shrinkage without any moist curing. The range of humidity will be varied from 4.5% to 100%, with the lowest humidity also being at a lower temperature. The daily fluctuation in humidity was monitored at each storage location and compared to average humidity for overall sensitivity of the shrinkage measurement. Specimen prism sizes of 1", 2", and 3" provide the range of surface areato-volume ratios of 4.178, 2.178, and 1.511. Only two mixtures were studied both with mortar and varying aggregate-to-cement proportions of 1.23:1 and 1.17:1. Additionally, a shrinkage prediction was calculated from ACI Committee 209 equations and was compared to measured values. Chapter 3 covers using energy dispersive spectroscopy for the verification of TiO2, thermo-gravimetric analysis (TGA), and mass spectrometry (MS) for the estimation of carbonation rate between plain mortar to two mortars embedded with 1% photocatalytic TiO2 particles and sprayed on TiO2 particles. All samples will be exposed to an outdoor environment with a CO2 concentration of around 410 ppm in Utah for up to 100 days. 1.6 Techniques 1.6.1 Standard Test Procedures Used or Modified in Studies The American Society of the International Association for Testing and Materials (ASTM) is an international standards organization for testing methods and materials. In this study, the materials and concrete mix procedures were followed based on the standards listed below. 5 • ASTM C150 / C150M - 11 Standard Specification for Portland Cement • ASTM C157 / C157M - 08 Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete • ASTM C192 / C192M - 16a Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory • ASTM C33 / C33M - 16 Standard Specification for Concrete Aggregates • ASTM C305 - 11 Standard Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency • Petrographic Methods of Examining Hardened Concrete: A Petrographic Manual (2004), Federal Highway Administration. 1.6.2 Statistics Used in Shrinkage Study The sensitivity will be ranked by comparing the difference of slopes for each two sets of data for the same variable (humidity) in this study. It will be considered "less sensitive" when the percent difference in slopes is small. A T-test will be used to statistically compare the mean values between different shrinkage measurements. A T-test is used instead of a normal distribution when there are small sample sizes (O'Mahony 1986). When performing a T-test, a null hypothesis is created and a level of significance is selected (in this study 5% was chosen). The result shows a probability P-value. For this study, when the P-value is smaller than 0.05, the null hypothesis is rejected, indicating that the means are statistically different. Coefficient of variance (CV) will also be used in this study to statistically analyze the 6 variability of replicas. Statistically, CV values smaller than 15% are considered to be low variability and to be eligible for performing a T-test. CHAPTER 2 FREE SHRINKAGE ON CEMENT MORTARS Cement mortar is widely used in masonry, and it can bind concrete, bricks, and stones. Cement mortar is also a good finishing and repairing material that could be used to fix cracking on concrete or asphalt pavements. Drying shrinkage happens in concrete or cement mortars due to water loss. The larger coarse aggregates in concrete resist the volumetric change. Thus, cement mortar is considered to have more paste volume fraction compared to concrete mixtures. To avoid the influence of aggregate size on the measured shrinkage, only cement mortar was investigated based on ASTM C157 in this chapter. 2.1 Shrinkage Types and Mechanism Shrinkage happens when concrete starts hardening, exhibits logarithmic growth with time, and is mostly irreversible. There are four different types of shrinkage, thermal shrinkage, plastic shrinkage, drying shrinkage, and autogenous shrinkage (Li 2011) as described herein. Thermal shrinkage is the concrete contraction caused by the temperature difference between concrete and the surrounding environment. When the ambient temperature is lower than that of concrete, the concrete will shrink. 8 Plastic shrinkage happens at a very early age, only a few hours after adding water, before the concrete has hardened. When the rate of water evaporation from the concrete surface exceeds that of the migration of internal water to the surface, the surface layer volume decreases causing shrinkage, often leading to spalling and surface micro-cracking. Drying shrinkage occurs after the concrete has set and hardened and is the loss of the water that has not reacted with cement. The excessive water in the interior of concrete that migrates to the surface and evaporates to the environment produces a net volume reduction and causes cracking if the concrete is restrained from this volumetric change. Autogenous shrinkage is the volume contraction of concrete that happens at an early age, less than 24 hours after adding water. Autogenous shrinkage occurs without moisture transfer from concrete to environment, which is a result of chemical shrinkage due to the hydration of cement. This shrinkage study will primarily investigate drying shrinkage and has some concurrent influence from thermal shrinkage that will be accounted for with backcalculation, as detailed in section 2.3.4. 2.2 Shrinkage Magnitude Prediction There are many factors that could have an influence on drying shrinkage. Since it is the water loss that leads to drying shrinkage, the Portland Cement Association states that a low water content would decrease the magnitude of shrinkage, as well as by maximizing coarse aggregate content (PCA 2002). In 1929, an article originally proposed the length change test to measure the drying shrinkage behavior for clay and shales. At the time, the authors investigated the influence 9 of different temperature and humidity conditions, such as 26 °C versus 105 °C temperature and 85% versus 94% RH. From this early study, they found that the shrinkage was greater with increased drying time and at 26°C and 94%RH (McClenahan and Rigling 1929). Studies have shown that ambient relative humidity has an influence on concrete shrinkage. Pihlajavaara investigated cement mortar specimen shrinkage in storing environments from 0% RH to 100% RH and found that shrinkage is greater in the low humidity environments (Pihlajavaara 1974). Cebeci et al. studied the shrinkage for concrete mortars moist cured at 33%, 75% and 92%RH; the investigation found that drying shrinkage was increased with curing in lower humidity environments (Cebeci et al. 1989). Alsayed and Amjad studied concrete slabs for shrinkage under different humdity conditions. The results again verified that low humidity environment resulted in more shrinkage than high humidity conditions (Alsayed and Amjad 1994). 2.3 Shrinkage Prediction and Moisture Diffusion American Concrete Institute's Committee 209 has derived a set of equations to predict drying shrinkage as shown below, estimating after 7 days moist curing that at an ambient 40% RH would produce an ultimate shrinkage of 780 x 10-6 in/in, and at 70% RH would produce 546 x 10-6 in/in. (ACI Committee 209 1992). The definitions and calculations for each coefficient are shown in Table 1. In 1995, Bažant and Baweja developed a shrinkage prediction equation based on the different humidity in the pores and environment as shown in Equation (1) (Bažant and Baweja 1995). 10 𝜀𝜀𝑠𝑠ℎ (𝑡𝑡) 𝜀𝜀𝑠𝑠ℎ ∞ (ℎ𝑒𝑒 ) = (𝑡𝑡) ℎ0 −ℎ ℎ0 −ℎ𝑒𝑒 − tanh 𝜑𝜑 (1) where, 𝑡𝑡−𝑡𝑡0 𝜑𝜑 = 𝜏𝜏𝑠𝑠ℎ ; ℎ0 : initial relative humidity in the pores; ℎ𝑒𝑒 : environmental relative humidity; 𝜀𝜀𝑠𝑠ℎ : average shrinkage strain in the cross section; 𝜀𝜀𝑠𝑠ℎ ∞ : final value of shrinkage strain corresponding to ℎ𝑒𝑒 ; 𝜏𝜏𝑠𝑠ℎ : time at half drying shrinkage; 𝑡𝑡 − 𝑡𝑡0 : duration of drying. Based on a composite model (cement and aggregate), Eguchi and Teranishi predicted drying shrinkage of concrete using Equation (2) (Eguchi and Teranishi 2005). 𝜀𝜀𝑠𝑠𝑠𝑠 𝜀𝜀𝑠𝑠𝑠𝑠 = [1−(1−𝑚𝑚∗𝑛𝑛)𝑉𝑉𝑎𝑎 ][𝑛𝑛+1−(𝑛𝑛−1)𝑉𝑉𝑎𝑎 ] 𝑛𝑛+1+(𝑛𝑛−1)𝑉𝑉𝑎𝑎 (2) where, the suffixes c, a, m stand for the entire concrete composite, the aggregate, or the matrix, respectively; 𝜀𝜀𝑠𝑠 : drying shrinkage strain; 𝑛𝑛 = 𝐸𝐸𝑎𝑎 ⁄𝐸𝐸𝑚𝑚 ; 𝑚𝑚 = 𝜀𝜀𝑠𝑠𝑠𝑠 ⁄𝜀𝜀𝑠𝑠𝑠𝑠 ; 𝐸𝐸: Young's modulus; 11 𝑉𝑉: volume ratio; Another shrinkage prediction equation was introduced by Moon and Weiss in 2006, based on the change of humidity as shown with Equation (3) and (4) (Moon and Weiss 2006). 𝜀𝜀(𝑡𝑡) = 𝜀𝜀𝑆𝑆𝑆𝑆−𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 ∗ ∆𝑅𝑅𝑅𝑅(𝑡𝑡) ∆𝑅𝑅𝑅𝑅(𝑥𝑥, 𝑡𝑡) = 𝑅𝑅𝑅𝑅𝑖𝑖 − (𝑅𝑅𝑅𝑅𝑖𝑖 − 𝑅𝑅𝑅𝑅𝑠𝑠 ) ∗ 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 (3) 𝑥𝑥 2√𝐷𝐷∙𝑡𝑡 (4) where, 𝜀𝜀𝑆𝑆𝑆𝑆−𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 : constant shrinkage coefficient; ∆𝑅𝑅𝐻𝐻(𝑡𝑡): the difference between 100% RH and the internal relative humidity RH of a concrete specimen at a given time and depth; 𝑅𝑅𝑅𝑅𝑖𝑖 : internal relative humidity; 𝑅𝑅𝑅𝑅𝑠𝑠 : relative humidity at the surface of the specimen; 𝑥𝑥: depth from the drying surface; 𝐷𝐷: aging moisture diffusion coefficient; 𝑡𝑡: drying time. Drying shrinkage is closely related to diffusion rate, which is related to the surface area-to-volume of the concrete. In 1946, Pickett studied the relationship between diffusion of vapor and moisture content in concrete, and a linear diffusion equation was solved by applying the heat transfer equation (Pickett 1946). However, later studies found that the moisture diffusion in concrete follows a nonlinear equation (Bažant and Najjar 12 1972). In 1982, Sakata also predicted the moisture distribution in concrete with a nonlinear diffusion equation and compared the experimental values with computed values. Sakata found that moisture diffusion is rapid near the surface but slow in the interior based on Bažant's moisture diffusion equation (Sakata 1983). The ACI 209 prediction equation also included volume-to-surface ratio, an inverse of the surface-to-volume used in the diffusion models (ACI Committee 209 1992). Despite these previously mentioned studies, most experiments were performed following ASTM C157 standard. However, the suggested curing environment, surface-tovolume ratios, and air storing conditions cannot be followed exactly. Thus, this study investigates the influence of surface-to-volume ratios using different specimen sizes, the specimen storage environment ranging from about 10 to 90% RH and 10 to 25°C, and for two different fine aggregates to cement mass proportions partially followed by ASTM C157 standard. 2.4 Methodology 2.4.1 ASTM C157 Modification The shrinkage test in this study was based on ASTM C157 standard, but three modifications were made to meet the research objective. These modifications were on specimen size, curing procedure, and air storage environment as described herein. 2.4.1.1 Specimen Sizes ASTM C157 defines the test specimens. For mortar, the test specimens shall be 1" prisms. For concrete, the test specimens shall be 4" prisms if all the coarse aggregate 13 passes through a 2-in sieve, or shall be 3" prisms if all the aggregate passes through a 1-in sieve. In this study, there were no coarse aggregates used at all, but three different test specimens were investigated (1", 2", and 3" prisms) to determine the sensitivity of the shrinkage magnitude relative to different surface area to volume ratios of 4.178, 2.178, and 1.511, respectively. 2.4.1.2 Curing Procedures To minimize the variation in length due to temperature, ASTM C157 suggests specimens be moist cured for 28 days before storing. In this study, all specimens were not moist cured at all to investigate temperature influence. 2.4.1.3 Air Storage ASTM C157 also suggests that to measure shrinkage in an air storage environment, a relative humidity of 50 ± 4% and a temperature of 23 ± 2ºC must be maintained. Not all testing labs can maintain such narrow climate controls. Thus, seven different storing conditions with different average humidity and temperature levels, as well as different magnitudes of fluctuation, were studied to determine the test method sensitivity relative to average humidity levels and daily fluctuation levels on shrinkage values. 2.4.2 Storing Conditions 2.4.2.1 RH and Temperature Table 2 summarizes the RH and temperature monitoring information gathered for different locations. The resolution of the digital USB logger at the Utah Department of 14 Transportation (UDOT) was 1°F (0.55°C) and 0.5% RH, while all other digital USB loggers had a resolution of 0.5°C and 0.5% RH. The gauge on the humidity chamber displays to the nearest 0.5°C and 0.5% RH, while the dial gage in the refrigerator showed increments of 2°C and 1% RH (from 10 to 100%). When obtaining RH% data from the refrigerator, and when the dial showed a value below 10%, a rough estimation was used in the analysis of environment condition. The maximum, minimum, average temperature, and RH data for each location through all the monitoring days are shown in Figure 1 and listed in Table 3. The specific daily measured temperature, humidity, and fluctuation readings for each location can be found in Appendix A. The readings verified that the refrigerator is colder and lower in humidity than any other locations. The highest humidity was found in the fog room. The daily fluctuations of temperature and humidity for each location were calculated and are shown in Table 4. The humidity chamber was verified to maintain a constant temperature and humidity expected for the ASTM C157 specification, and was selected as the control condition. The fog room 130D also had a stable humidity and temperature environment. A t-test was made between each two of those seven locations. For each combination of data sets, the same recording frequency was used to determine if there is a correlation/trend between locations. By comparing the P-values shown in Table 5 and Table 6, it was confirmed that there were no similarities (p-value < 0.05) in temperature and humidity between these locations. Since the recording dates and time were different for each location, the humidity and temperature data cannot be correlated; thus, p-values were calculated without matching the starting and recording time. 15 2.4.2.2 Significance of Locations All seven locations selected in this study were used to simulate six laboratory environments with an additional control location (humidity chamber) that followed ASTM C157 storage requirements. After comparing the shrinkage values in those seven different locations, recommendations on modifying the test standard based on alternative RH and temperature average values and fluctuation will be composed. The goal of these new recommended storage requirements will be based on the location that provides more consistency in shrinkage measurements regardless of the reported shrinkage age and the specimen size selected. 2.4.3 Materials, Mix Design, and Specimens A local ASTM C150 classified Type I/II/V cement from LaFarge-Holcim's Devil's slide plant was used for this study, as well as an ASTM C33 standard natural sand from Staker Parson's Beck street plant. Two mix designs were created. A saturated surface dry (SSD) cement:sand:water mass ratio of 1 : 1.23 : 0.53 was used for mix 1 and mass ratio of 1 : 1.17 : 0.53 was used for mix 2. The mix design in pounds per cubic yard was summarized in Table 7. Batch weight can be found in Appendix B showing the oven-dry batched amounts. Before mixing, all natural sands were oven dried for approximately 24 hours at a temperature of 80 degrees Celsius. Specimens were mixed per ASTM C305. All specimens were air-cured for the entire duration, rather than performing the 28-day limesaturated bath curing recommended in the ASTM C157 standard. Shrinkage from mix 1 was only measured using the humidity chamber and fume hood locations, while 16 shrinkage from mix 2 was measured for all locations. For each batch, at least four 1x1x11.25" prisms (surface area to volume ratio of 4.18), three 2x2x11.25" prisms (surface area to volume ratio of 2.18), and four 3x3x11.25" prisms (surface area to volume ratio of 1.51) were made. 2.4.4 Measurements To determine the shrinkage under different curing conditions, length change tests were performed. Per ASTM C157, a length change test is divided into comparator reading and calculation. In this study, with each test specimen in the comparator, the dial readings were observed and recorded. The length change of any specimen at any age was calculated following Equation (5). The weight change was also measured to verify whether consistent shrinkage was occurring in test specimens. ∆𝐿𝐿𝑥𝑥 = 𝐶𝐶𝐶𝐶𝐶𝐶−𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖 𝐶𝐶𝑅𝑅𝑅𝑅 𝐺𝐺 ×10−6 (5) where, ∆𝐿𝐿𝑥𝑥 = length change of specimen at any age, 10-6in/in, 𝐶𝐶𝐶𝐶𝐶𝐶 = difference between the comparator reading of the specimen and the reference bar at any age, in, 𝐺𝐺 = the gage length, 10 in. For each of those seven locations, at least three replicates of each prism size were measured. All the specimens were demolded at an early age and measured at about 12 17 hours from the time of mixing. Extra samples were made because sometimes the specimens were fragile and broke during demolding at this early age. The measurement ages for length change and weight change were taken at 12 hours (0.5 days), 24 hours (1 day), 3 days, 7 days, 14 days, 21 days, 28 days, and 56 days after water was added. The specific dates and times for mixing and measurements are shown in Appendix C. Even though shrinkage samples were stored in different locations, all samples were measured at a room temperature of approximately 25 ºC and relative humidity of about 40%. Thermal contraction or expansion could happen during measurement. However, since each measurement lasted only for approximately 1 minute, a relatively short period compared with storing time, thermal expansion during the measurement time alone was not considered in this study. Only the shrinkage specimens stored in the refrigerator environment, which had a significantly different temperature of 4.5 ºC on average, were later separated into the predicted thermal contraction versus the remaining net shrinkage assumed to be due to drying in the low RH, as calculated in Equation (6). Additionally, it was assumed that the internal temperatures within the refrigerator samples were uniformly at the external refrigerator temperature. ∆𝐿𝐿 = 𝐶𝐶𝐶𝐶𝐶𝐶 ∗ ∆𝑡𝑡 ∗ 𝐿𝐿0 (6) where, ∆𝐿𝐿: length change due to temperature change, in; ºC; 𝐶𝐶𝐶𝐶𝐶𝐶: thermal coefficient of concrete, range from 7.4 to13E-6/ ºC, here use 10E-6/ 18 ∆𝑡𝑡: temperature change, ºC; 𝐿𝐿0 : initial length, in. 2.5 Results 2.5.1 Overall Analysis 2.5.1.1 Repeatability An example of four 1" prism sample replicates stored in the humidity chamber and fog room is shown in Figure 2. The coefficient of variance (CV) was calculated and is shown in Table 8. The variation in shrinkage for the fog room was significantly high, indicating it is not a suitable environment in which to measure shrinkage. 2.5.1.2 Thermal Contraction Adjustment for Refrigerator All samples located in the refrigerator were first stored at room temperature (around 25 ºC) for about 12 hours, and after the first readings, they were moved to refrigerator at 10 ºC for storing. Thus, thermal contraction adjustment was applied for specimens stored in the refrigerator in this study. All future graphs and data showing refrigerator results are based on the adjusted values. Adjusted shrinkage values for thermal contraction stored in the refrigerator are compared in Figure 3. 2.5.1.3 Shrinkage for Each Environment As the humidity chamber was set to be the control environment, a plot that shows the difference between each location and the humidity chamber was generated. A comparison of extreme storage environments (refrigerator to fog room) is to plot the individual 19 shrinkage in comparison to the same average control (humidity chamber) environment as shown in Figure 4. Comparison plots for other locations are shown in Appendix D. The average drying shrinkage measurement plots versus age of each environment and each prism size of mix 2 are shown in Figure 5. As expected, the least shrinkage was found in the fog room, which has the highest humidity. Among the 1" prisms, the drying shrinkage is the greatest in the refrigerator after 21 days. For 2" prisms, the shrinkage is the greatest in UDOT after 21 days. While among 3" prisms, the shrinkage appeared to be greatest in the humidity chamber at a constant 50% RH and 23°C. Further analysis on the specific humidity and surface area-to-volume ratio are made hereafter. A T-test was performed for those shrinkage values at each location. When the P-value is smaller than 0.05, this indicates that the shrinkage magnitudes are different. Tables 9 and 10 show the P-values comparing whether the shrinkage magnitudes are the same between two locations. Since storage room 130C, room 110A, and UDOT lab are all indoor lab rooms, in Table 9, these three rooms were averaged together and classified as "Lab Rooms" when compared to other four locations. A comparison of P-values between just these three lab rooms was created and listed in Table 10. The P-value between the humidity chamber and fume hood is higher than 0.05 at the 56 days and thus these environments cannot be statistically differentiated now. All other storage environments are considered significantly different. 2.5.1.4 Weight Change During Shrinkage It is expected that weight loss happens for concrete samples when there is a low external humidity compared to the inside of the concrete. Based on the theory proposed 20 by Pickett, moisture transfer only happens when there is a humidity difference between concrete and environment. It is expected that when the interior moisture reaches the same as the ambient environment, moisture absorption stops. It is also expected that a higher moisture transfer rate exists in samples that have higher surface-to-volume ratio. First off, all samples exhibited an initial weight loss from the time of mixing to the first 3 days. From the plots shown in Figure 6, the prisms stored in the fog room, regardless of specimen size, started re-gaining some of the weight starting after 7 days, due to the expected absorption of moisture from high humidity environment. It can also be seen in many of the other environments that there is a weight re-gain among the 1" prisms, Figure 6a. The samples stored in the refrigerator at a low humidity all continued to lose weight regardless of specimen size. The samples measured in this study verified that a high surface-to-volume ratio for concrete is more sensitive to humidity, detailed in section 2.4.2.2; and the weight varies more for a sample of high surface-to-volume ratio before humidity equilibrates. 2.5.2 Average and Daily Fluctuation in Humidity Influence on Shrinkage 2.5.2.1 Shrinkage and Average Relative Humidity The average shrinkage measurement for all the 1", 2", and 3" prisms of mix 2 versus average humidity of each environment are shown in Figure 7. The plot confirms that with the increase of RH, shrinkage decreases and shows that 1" prisms are the most sensitive to RH. 21 2.5.2.2 Shrinkage and Average Relative Humidity Fluctuation The comparison of shrinkage values at different relative humidity fluctuations was made. To minimize humidity's influence, five locations were compared without extremely high humidity (Fog Room) and extremely low humidity (Refrigerator). As shown in Figure 8, no trend line was added as low R square values. 2.5.3 Size Effects on Shrinkage In this study, 1", 2", and 3" prisms were tested and analyzed by their dimensions and surface-to-volume ratios of 4.18, 2.18, and 1.51. Figure 9 shows the average length changes for these three prism sizes for mix 2 stored in the humidity chamber (23 °C, 50% RH), while Figure 10 is the relationship between surface-to-volume ratio and shrinkage. The weight change plot indicates the 1" prisms started absorbing water at 7 days, as explained before. The other shrinkage and weight change figures for other locations can be found in Appendix E. Table 11 lists the p-values to compare specimen sizes at each age; samples stored in the humidity chamber and fume hood were combined due to the similar humidity and temperature environment. Again, p-values less than 0.05 indicate the prisms give statistically different shrinkage values. The table shows that storage room 130C has significant influence on prism sizes; at 56 days, size effects are reduced; and the refrigerator has the least size effects among all locations. 2.5.4 Shrinkage of Mortars with Sand-Cement Proportioning The mass ratio of cement to aggregate (1:1.17 versus 1:1.23) was also studied on the influence of measured shrinkage. Figure 11 is a comparison of the different mix designs 22 at the same storage conditions (humidity chamber). No obvious trend can be seen from the plot of average shrinkage values between mixes. Furthermore, Table 12 shows the pvalues comparing shrinkage of the different mixtures. Among 1" prisms and the humidity chamber, which are both specified in the current ASTM C157 standard, one cannot distinguish between the mixtures. However, a subtle difference between mixes is shown for 3" prisms after 7-day storing. 2.5.5 Shrinkage Predictions 2.5.5.1 Shrinkage Prediction Based on ACI Committee 209 Equations The predicted and measured shrinkage values at different locations were compared from ACI Committee 209 equations. The coefficients were determined as follows: all the samples are mortar, thus the fine aggregate coefficient 𝛾𝛾𝑓𝑓 equals 1.1; the calculation of relative humidity coefficient (𝛾𝛾ℎ ), volume-to-surface ratio coefficient (𝛾𝛾𝑉𝑉⁄𝑆𝑆 ), thickness coefficient (𝛾𝛾𝑡𝑡ℎ ), and cement content coefficient (𝛾𝛾𝑐𝑐 ) are listed from Table 13 to 15. A back-calculation of the curing coefficient was made since there was no moist curing while the ACI 209 equation only accounts for shrinkage based on 7 days moist curing. The back-calculated 𝛾𝛾𝑐𝑐𝑐𝑐 was found to be 2, so that the measured average shrinkage matched the prediction for a 3" prism (as is used in the ACI 209 equation) after 56 days and for the humidity chamber environment (which meets the ASTM C157 standard RH and temperature requirements); all other coefficients were assumed to be 1.0 since there were no data available on them. Error and squared error were calculated to compare the difference between the measured and predicted shrinkage values. Table 16 shows the comparison between 23 predicted and measured shrinkage values for samples stored in the humidity chamber and refrigerator at 56 days while Figure 12 shows the comparison between predicted and measured shrinkage values for samples stored in humidity chamber at all ages. A completed comparison of predicted versus measured values is shown in Appendix F. The difference between predicted and measured values (measured values minus predicted values) shows where the model underpredicts (positive values) and overpredicts (negative values). The squared error can be used to illustrate that the magnitude of difference is greater in the refrigerator than the humidity chamber or fog room. Additionally, squared error versus volume-to-surface ratio plots for samples stored in the humidity chamber for 21 days, 28 days, and 56 days were generated, as shown in Figure 13. In general, as the volume-to-surface ratio increased, squared error increased for samples stored for 21 days, while it dramatically decreased for samples stored for 56 days. There was no obvious trend seen from the squared error versus relative humidity plot shown in Figure 14. 2.5.5.2 Moisture Diffusion Prediction (Moon and Weiss) The prediction was also performed based on the equations induced by Moon and Weiss as shown in Chapter 2. The water diffusion coefficient was selected to be 0.133 cm*cm/day based on 0.53 water/cement ratio and 0-day moist curing (Bažant and Najjar 1972), which was converted to be 0.021 in*in/day. Two cases were studied and predicted under the Moon and Weiss model, shrinkage for samples stored in the refrigerator and in humidity chamber. The constant shrinkage coefficient (from Equation (3)) was calculated using the initial ACI Committee 209 24 suggested ultimate shrinkage, and applying the coefficients not associated with drying time, humidity, or specimen size. Thus, the following ACI coefficients were applied to the 780 microstrain: moist curing coefficient, slump coefficient, air entrainment coefficient, fine aggregate coefficient, and cement content coefficient in section 2.4.5.1 as listed in Table 17. The constant shrinkage coefficient was found to be 2094 in/in×10-6 for the Moon and Weiss prediction. Since concrete shrinkage was considered due to water diffusion, an internal relative humidity distribution prediction plot at different depths into the specimens was created for these two cases as shown in Figure 15. The figure shows that the shrinkage values decrease with the increasing of depth from sample surface. Additionally, it also confirmed that water diffused out of the sample more for samples at surface at longer storing age in lower relative humidity environment. The selection of predicted shrinkage values from this model was at the center (1.5" depth of 3" samples, 1" depth of 2" samples, and 0.5" depth of 1" samples, respectively) since the two pins for the measurement were located at the center of samples. Error and squared error were also used with this prediction model to find out if it is underpredicted (positive error values) or overpredicted (negative error values) from the actual measured shrinkage values. As an example, the comparison between these two cases at 56 days is listed in Table 18. From Figure 16 and Appendix G, the Moon and Weiss model underpredicts shrinkage values at all ages for all storing locations; possible reasons for this could be the selection of diffusion coefficient, the constant shrinkage coefficient, or the parameters from ACI Committee 209 equations. However, from the comparison in Figure 17, this model fits samples stored in the refrigerator better since it 25 has lower squared error values than those for samples stored in the humidity chamber. 2.6 Summary and Findings This study focused on the shrinkage of cement mortars, measured from 0.5 to 56 days, and comparing the influence of environmental storage conditions, samples sizes, and aggregate-cement proportioning. The results could be concluded as follow. • In general, a higher humidity during the storage of the specimens was verified to create the least amount of shrinkage on cement mortars. • When comparing the sensitivity among sizes of samples at different relative humidity and humidity fluctuations, it was found 1" prisms are most sensitive to RH, while there was no trend to RH fluctuation. Furthermore, a longer storing age increases the shrinkage sensitivities to RH. • A longer storage age reduces the sensitivity on shrinkage values associated with surface-to-volume ratio. Furthermore, the shrinkage magnitude was higher for greater surface-to-volume ratios. • For a 1" prism size and humidity controlled environment, a small adjustment in fine aggregates to cement proportioning did not show a significant difference in shrinkage values. • Using the ACI 209 shrinkage prediction equation, prediction parameters were changed to have no initial curing. In the 50% controlled humidity environment, the model was found to underpredict early shrinkage and overpredict later shrinkage (for ages greater than 28 days). Samples stored in the refrigerator exhibited the greatest difference between the measured lab and the model 26 predicted shrinkage, with the model highly overpredicting shrinkage at this low humidity environment for 2" and 3" prisms. Samples modelled for the fog room had the least difference but significantly underpredicted compared to the actual lab samples. • Using the Moon and Weiss shrinkage prediction equations based on moisture diffusion, it was confirmed the internal moisture diffuses out of the sample more for smaller samples and with longer exposure ages. The model prediction significantly underpredicts shrinkage for a 50% controlled humidity environment, but more closely predicts shrinkage for the 5% low humidity environment. These findings lead to recommended alterations to the existing ASTM C157 standard. If it was wanted to be able to use any specimen size for determining shrinkage, the storage environment in the refrigerator (0% to 10% RH) or with longer storage ages were found to have the least influence of specimen size on shrinkage. Or if it was wanted to have the ability to store samples in any humidity environment, samples should be of 3" size to minimize humidity influences regardless of environment (from 5 to 100% RH). 27 Table 1 Shrinkage Prediction Coefficients from ACI Committee 209 𝜀𝜀𝑠𝑠ℎ 𝜀𝜀𝑠𝑠ℎ−𝑢𝑢𝑢𝑢𝑢𝑢 𝛾𝛾𝑡𝑡 𝛾𝛾ℎ Shrinkage at a given time after curing Ultimate shrinkage Time coefficient (based on 7 days initial moist curing) Ambient RH coefficient 𝜀𝜀𝑠𝑠ℎ (𝑡𝑡) = 𝜀𝜀𝑠𝑠ℎ−𝑢𝑢𝑢𝑢𝑢𝑢 ∗ 𝛾𝛾𝑡𝑡 780−6 ×𝛾𝛾𝑠𝑠ℎ where: 𝛾𝛾𝑠𝑠ℎ = 𝛾𝛾ℎ ∗ 𝛾𝛾𝑐𝑐𝑐𝑐 ∗ 𝛾𝛾𝑡𝑡ℎ ∗ 𝛾𝛾𝑠𝑠 ∗ 𝛾𝛾𝑓𝑓 ∗ 𝛾𝛾𝑒𝑒 ∗ 𝛾𝛾𝑐𝑐 ∗ 𝛾𝛾𝑉𝑉⁄𝑆𝑆 t / (35 + t) for moist curing 1.0 for RH<40 1.4 − 0.0102(𝑅𝑅𝑅𝑅) for 40<RH<80 3.0 − 0.030(𝑅𝑅𝑅𝑅) for 80<RH<100 Curing age (days) 𝛾𝛾𝑐𝑐𝑐𝑐 1 1.2 3 1.1 7 1.0 14 0.93 28 0.86 1.43 for 1-inch thickness 1.3 for 2-inch thickness 1.17 for 3-inch thickness 0.89 + 0.04(𝑆𝑆) 0.33 + 𝐹𝐹 ⁄75 for F<50 0.88 + 𝐹𝐹 ⁄430 for F>50 𝛾𝛾𝑐𝑐𝑐𝑐 Initial moist curing coefficient 𝛾𝛾𝑡𝑡ℎ Thickness coefficient 𝛾𝛾𝑠𝑠 𝛾𝛾𝑓𝑓 Slump coefficient Fines coefficient 𝛾𝛾𝑒𝑒 Entrained air coefficient 𝛾𝛾𝐶𝐶 Cement content 0.72 + 𝐶𝐶 ⁄2500 coefficient Volume-to1.2 𝑒𝑒𝑒𝑒𝑒𝑒(−0.12 𝑉𝑉⁄𝑆𝑆) surface coefficient 𝛾𝛾𝑉𝑉/𝑆𝑆 t: days after initial curing 0.95 + 𝐴𝐴⁄120 RH: Relative Humidity (from 0 to 100) S: Slump (inches) F: weight % of fine aggregates of total aggregate (from 0 to 100) A: volume % of air entrainment (from 0 to 100) C: cement content (lbs/cy) V/S: volume/surface area ratio (in) 28 Table 2 RH and Temperature Monitoring Information for Different Locations Expected Relative Humidity 10% Expected Temperature 10°C Monitoring Method Dial Gauge Duration between Readings (min) Specific dates 50% 23°C Digital Gauge Specific dates Fluctuating <50% 25°C USB Logger 10 Room 110A Storage Room 130C UDOT Fluctuating <50% 25°C USB Logger 10 Fluctuating ~50% 25°C USB Logger 10 ~50% 25°C USB Logger 30 Fog Room 130D 90% 25°C USB Logger 10 Location Refrigerator Humidity Chamber Fume Hood Table 3 RH and Temperature Data for Different Locations Location Refrigerator Humidity Chamber Fume Hood Room 110A Storage Room 130C UDOT Fog Room 130D Minimum 0.0 50.0 18.5 14.0 26.0 32.5 75.5 RH (%) Maximum 12.0 50.0 54.5 53.0 68.5 55.5 104.0 Average 4.5 50.0 34.6 29.4 53.7 44.3 99.9 Temperature (∘C) Minimum Maximum Average 7.0 15.0 11.2 23.0 23.0 23.0 21.5 29.0 24.5 16.0 31.5 23.7 15.0 26.5 23.5 23.3 27.8 25.4 17.5 25.0 21.9 Table 4 Temperature and Humidity Daily Fluctuation for Different Locations Location Refrigerator Humidity Chamber Fume Hood Room 110A Storage Room 130C UDOT Fog Room 130D Minimum 3.0 0.0 7.0 6.0 3.0 2.0 0.5 RH Fluctuation (%) Maximum Average 5.0 4.5 0.0 0.0 24.0 14.2 22.0 14.1 30.0 9.2 14.0 5.7 21.5 3.7 Temperature Fluctuation (∘C) Minimum Maximum Average 3.0 6.0 4.0 0.0 0.0 0.0 1.5 7.0 3.5 1.5 6.5 3.7 0.0 5.5 1.1 0.6 2.8 1.1 0.0 2.0 1.0 29 Table 5 P-values for Temperature Humidity Chamber Fume Hood Room 110A Storage Room 130C UDOT Fog Room Refrigerator 5.99E-7 1.27E-8 6.78E-9 2.48E-8 2.12E-7 3.02E-7 Humidity Chamber - 4.07E-7 0.01 0.02 1.35E-35 3.87E-8 Fume Hood - - 0.02 7.30E-4 3.33E-4 1.41E-13 Room 110A - - - 0.50 1.80E-7 1.68E-7 Storage Room 130C - - - - 4.50E-13 2.97E-8 UDOT Lab - - - - - 2.44E-31 Table 6 P-values for Relative Humidity Humidity Chamber Fume Hood Room 110A Refrigerator 2.61E-8 1.47E-12 8.56E-10 6.37E-14 3.17E-10 1.89E-11 Humidity Chamber - 1.13E-7 1.59E-35 4.87E-5 1.90E-12 1.26E-95 Fume Hood - - 0.02 6.21E-10 4.22E-5 8.76E-19 Room 110A - - - 6.48E-43 1.80E-28 2.05E-78 Storage Room 130C - - - - 8.81E-15 3.21E-61 UDOT Lab - - - - - 8.15E-70 Storage Room UDOT Lab 130C Fog Room Table 7 Mix Design Mix Materials Absorption Capacity Type II Cement Natural Sand Water 2.19% Mix 1 SSD Design Mass (pcy) Ratios 1697 1.00 2083 1.23 892 0.53 Mix 2 SSD Design Mass (pcy) Ratios 1307 1.00 1525 1.17 687 0.53 30 Table 8 Coefficient of Variance at Each Age and Each Environment and Sample Size* 7 days 14 days Locations 1" Prisms 2" Prisms 3" Prisms 1" Prisms 2" Prisms 3" Prisms Refrigerator 7.67% 20.2% 4.55% 5.65% 25.4% 4.97% Humidity Chamber 4.23% 0.72% 5.63% 5.31% 0.55% 8.98% Fume Hood 5.62% 4.73% 10.24% 6.41% 3.82% 4.03% Storage Room 130C 1.24% 2.70% 5.84% 1.10% 1.15% 5.62% Room 110A 1.85% 4.38% 9.02% 1.86% 6.35% 4.42% UDOT Lab 3.10% 13.01% 12.45% 2.72% 10.94% 8.35% Fog Room 31.9% 19.2% 16.6% 51.4% 8.77% 13.1% 28 days 56 days Locations 1" Prisms 2" Prisms 3" Prisms 1" Prisms 2" Prisms 3" Prisms Refrigerator 2.61% 15.1% 1.92% 2.61% 9.46% 3.44% Humidity Chamber 5.15% 1.61% 6.59% 6.63% 2.35% 5.55% Fume Hood 8.91% 3.64% 6.65% 7.77% 3.33% 5.67% Storage Room 130C 1.15% 1.33% 5.62% 0.80% 1.31% 3.50% Room 110A 2.44% 3.27% 0.96% 1.27% 2.60% 0.68% UDOT Lab 2.48% 7.40% 6.84% 2.59% 7.40% 5.09% Fog Room 8.44% 58.2% * Bold value means high variance (CV > 15%) 19.6% 53.2% 7.26% 22.7% Table 9 P-values Between Different Environments for 1" Prisms at 56 Days Locations Refrigerator Refrigerator Humidity Chamber Fume Hood Lab Rooms * Fog room had a high CV as well. Humidity Chamber 0.0017 - Fume HoodLab RoomsFog Room* 0.0004 0.9917 - 4.57E-05 0.0047 0.0024 - 4.13E-05 0.0001 0.0001 3.01E-05 Table 10 P-values Between Different Lab Rooms for 1" Prisms Storage Room 130C Room 110A Storage Room 130C - Room 110A 0.0424 - UDOT Lab 0.0015 0.0003 31 Table 11 P-values Comparing Prism Sizes 7 days 28 days 56 days Locations 1" vs 2" 2" vs 3" 1" vs 2" 2" vs 3" 1" vs 2" 2" vs 3" Refrigerator 0.0262 0.2187 0.0625 0.0956 0.1732 0.0947 Humidity Chamber 0.0082 0.0118 0.5000 0.1915 0.3416 0.0194 Fume Hood 0.0027 0.0002 0.2819 0.0123 0.1057 0.1046 3.225E-05 1.135E-06 0.0006 1.573E-05 0.0008 Storage Room 130C 2.084E-06 Room 110A 0.0005 0.0005 0.1201 0.0172 0.6439 0.0691 UDOT Lab 0.0005 0.0028 0.0168 0.0010 0.2539 0.0025 Fog Room 0.0724 0.8082 0.0418 0.9769 0.1484 0.7989 * Fog room had a high CV meaning high p-values could be false due to high variability. Table 12 P-value Between Different Sand-cement Proportions 1" Prisms 2" Prisms 3" Prisms Days 7 28 56 7 28 56 7 28 56 Humidity Chamber 1 0.5262 0.8128 0.0077 0.0018 0.0161 0.0001 0.0025 0.0023 Fume Hood 0.0011 0.0008 0.0102 0.0079 0.0522 0.1611 0.0251 0.1965 0.5997 Table 13 Relative Humidity Coefficient %RH 𝛾𝛾ℎ Refrigerator 5% 1 Humidity Chamber 50% 0.89 Fume Hood 35% 1 Storage Room 130C 55% 0.839 Room 110A 29% 1 UDOT 43% 0.9614 Fog Room 100% 0 Table 14 Volume-to-surface Ratio Coefficient 1" Prism 2" Prism 3" Prism V/S 0.24 0.46 0.66 𝛾𝛾𝑡𝑡ℎ 1.43 1.30 1.17 𝛾𝛾𝑉𝑉⁄𝑆𝑆 1.17 1.14 1.11 32 Table 15 Cement Content Coefficient Cement Content 𝛾𝛾𝑐𝑐 Mix 1 1697 1.36 Mix 2 1307 1.22 Table 16 Comparison Between Predicted and Measured Shrinkage Values at 56 Days Stored in Refrigerator and Humidity Chamber Based on ACI Committee 209 1" Prisms 2" Prisms 3" Prisms 1" Prisms 2" Prisms 3" Prisms Refrigerator Humidity Chamber Prediction 2149 1903 1671 1913 1694 1488 56 Days Measured Error 1918 -232 1703 -200 1390 -281 1393 -519 1367 -327 1505 17 Square Error 53627 39804 79202 269718 106840 304 Table 17 Parameters Used for the Calculation of Shrinkage Coefficient for Mix 2 𝛾𝛾𝑐𝑐𝑐𝑐 Refrigerator 2 Humidity Chamber 2 𝛾𝛾𝑠𝑠 1 1 𝛾𝛾𝑓𝑓 1.1 1.1 𝛾𝛾𝑒𝑒 1 1 𝛾𝛾𝑐𝑐 Shrinkage Coefficient (MicroStrain) 1.22 2094 1.22 2094 Table 18 Comparison Between Predicted and Measured Shrinkage Values at 56 Days Stored in Refrigerator and Humidity Chamber from Moon and Weiss Refrigerator Humidity Chamber 1" Prisms 2" Prisms 3" Prisms 1" Prisms 2" Prisms 3" Prisms Prediction 1476 1015 644 777 534 339 56 Days Measured Error 1918 442 1703 688 1390 746 1393 617 1367 832 1505 1166 Squared Error 194968 473476 557246 380095 692775 1360279 33 120.0 b) 35 100.0 30 Temperature (∘C) a) %RH 80.0 60.0 40.0 25 20 15 Maximum 10 Minimum 20.0 5 0.0 0 Average Locations Locations Figure 1. Storing Condition a) %RH Distribution; b) Temperature Distribution 1600 1600 1400 1400 Shrinkage (10-6 in/in) b) 1800 Shrinkage (10-6 in/in) a) 1800 1200 1000 800 600 400 200 1000 800 600 400 200 0 -200 1200 0 0 20 40 Time (Days) 60 -200 0 20 40 Time (Days) Figure 2. Four 1" Prisms Shrinkage in a) Humidity Chamber; b) Fog Room 60 34 Shrinkage (10-6 in/in) a) 2500 2000 1500 Original 1000 Thermal Adjusted 500 0 0 20 40 60 Age (Days) Shrinkage (10-6 in/in) b) 2500 2000 1500 Original 1000 Thermal Adjusted 500 0 0 20 40 60 Age (Days) Shrinkage (10-6 in/in) c) 2500 2000 1500 Original 1000 Thermal Adjusted 500 0 0 20 40 60 Age (Days) Figure 3. Original and Thermal Adjusted Shrinkage at Refrigerator for a) 1" Prisms; b) 2" Prisms; c) 3" Prisms. 35 Shrinkage Relative to Average Humidity Chamber Shrinkage (10-6 in/in) 1000 800 600 400 Humidity Chamber 200 Refrigerator 0 -200 0 10 20 30 40 50 60 Fog Room Log. (Refrigerator) -400 Log. (Fog Room) -600 -800 -1000 Time (Days) Figure 4. Relative Average Shrinkage for Refrigerator and Fog Room Compared to Humidity Chamber, for 1" Specimens. 36 Shrinkage (10-6 in/in) a) 2000 Refrigerator 1600 Humidity Chamber 1200 Fume Hood 800 Room 110A 400 Storage Room 130C UDOT Lab 0 0 Shrinkage (10-6 in/in) b) 20 40 Time (Days) 60 2000 Refrigerator 1600 Humidity Chamber 1200 Fume Hood 800 Room 110A 400 Storage Room 130C UDOT Lab 0 0 Shrinkage (10-6 in/in) c) Fog Room 20 40 Time (Days) 60 Fog Room 2000 Refrigerator 1600 Humidity Chamber 1200 Fume Hood 800 Room 110A 400 Storage Room 130C UDOT Lab 0 0 20 40 Time (Days) 60 Fog Room Figure 5. Average Length Change of a) 1", b) 2", and c) 3" Prisms at Different Locations for Mix 2. 37 Weight Reduction (%) a) 12% 10% Refrigerator 8% Humidity Chamber 6% Fume Hood 4% Room 110A 2% Storage Room 130C 0% UDOT Lab 0 20 40 60 Fog Room Time (Days) Weight Reduction (%) b) 12% 10% Refrigerator 8% Humidity Chamber 6% Fume Hood 4% Room 110A 2% Storage Room 130C 0% UDOT Lab 0 20 40 60 Fog Room Time (Days) Weight Reduction (%) c) 10% Refrigerator 8% Humidity Chamber 6% Fume Hood 4% Room 110A 2% Storage Room 130C 0% UDOT Lab 0 20 40 60 Fog Room Time (Days) Figure 6. Weight Change of a) 1", b) 2", and c) 3" Prisms for Mix 2 a) 2500 b) 2500 Shrinkage (10-6 in/in) Shrinkage (10-6 in/in) 38 2000 1500 1000 500 2000 1" Prisms 1500 2" Prisms 1000 0 3" Prisms 1" Prisms 500 2" Prisms 0 0.0 50.0 100.0 Relative Humidity (%) 0.0 50.0 100.0 Relative Humidity (%) 3" Prisms Figure 7. Average Net Shrinkage (After Thermal Adjustment on Refrigerator Storage Samples) versus RH at a) 7 days; b) 56 days b) Shrinkage (10-6 in/in) Shrinkage (10-6 in/in) a) 2500 2000 1500 1000 500 0 2500 2000 1500 1000 2" Prisms 500 0 0.0 5.0 10.0 15.0 Humidity Difference 1" Prisms 3" Prisms 0.0 5.0 10.0 15.0 Humidity Difference (%) Figure 8. Shrinkage versus RH Fluctuation at a) 7 days; b) 56 days 39 a) 1600 b) 6% 5% Weight Reduction (%) Shrinkage (10^-6 in/in) 1400 1200 1000 800 600 400 4% 1" Prisms 3% 2" Prisms 2% 3" Prisms 1% 200 0 0% 0 20 40 Time (Days) 60 0 20 40 Time (Days) 60 Figure 9. Different Specimen Sizes for Mix 2 Stored in the Humidity Chamber: Average a) Shrinkage and b) Weight Change a) b) 1800 1600 Shrinkage (10-6 in/in) Shrinkage (10-6 in/in) 1600 1800 1400 1200 1000 800 600 400 1400 1200 0 6 Surface Area/Volume (in2/in3) 21 days 400 0 4 14 days 600 200 2 7 days 800 200 0 3 days 1000 28 days 56 days 0 2 4 6 Surface Area/Volume (in2/in3) Figure 10. The Influence of Surface-to-volume Ratios for Mix 2 Stored in a) Humidity Chamber; b) Storage Room 130C 40 a) b) 10% 1800 Mix 1 Average 1" 1600 8% Weight Loss (%) Shrinkage (10-6 in/in) 1400 1200 1000 800 600 400 Mix 1 Average 2" 6% Mix 1 Average 3" 4% Mix 2 Average 1" 2% Mix 2 Average 2" 0% Mix 2 Average 3" 200 0 -200 0 20 40 0 60 Time (Days) 20 40 Time (Days) 60 Figure 11. Different Mix Designs in the Humidity Chamber: Average a) Shrinkage and b) Weight Change Comparison Shrinkage (10-6 in/in) 2500 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 12. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Humidity Chamber at All Ages 41 300000 Squared Error 250000 200000 21 Days 150000 28 Days 100000 56 Days 50000 0 0.24 0.46 Volume-to-surface Ratio 0.66 Figure 13. Squared Error versus Volume-to-surface Ratio Plot for Samples Stored in Humidity Chamber at 21, 28, and 56 Days 120000 Squared Error 100000 80000 21 Days 60000 28 Days 40000 56 Days 20000 0 5% 29% 35% 43% 50% Relative Humidity 55% 100% Figure 14. Squared Error versus Relative Humidity Plot for Samples at 21, 28, and 56 Days 42 a) b) Humidity Depth from Surface (in) 0% 50% 100% Humidity 0% 50% 100% 0 0 0.2 0.2 3 Days 0.4 0.4 7 Days 0.6 0.6 0.8 0.8 28 Days 1 1 56 Days 1.2 1.2 1.4 1.4 14 Days 21 Days Figure 15. Humidity Change from Surface to Center for 3" Samples Stored in a) Humidity Chamber, b) Refrigerator 43 Shrinkage (in/in 10-6) a) 2500 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 500 3" Prisms Prediction 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Shrinkage (in/in 10-6) b) 2500 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 500 3" Prisms Prediction 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 16. Comparison Between Predicted and Measured Shrinkage Values for Samples Stored in a) Refrigerator and b) Humidity Chamber at All Ages 44 1600000 Squared Error 1400000 1200000 1000000 800000 Refrigerator 600000 Humidity Chamber 400000 200000 0 3 7 14 21 Age (Days) 28 56 Figure 17. Squared Error versus Storing Ages for 3" Samples Stored in Refrigerator and Humidity Chamber CHAPTER 3 CARBONATION Carbonation is a chemical reaction between Ca(OH)2 in concrete and CO2 in the environment. During this reaction, the product CaCO3 densifies in voids and cracks while also reducing the pH from average values of 12 to 14 down to 8 or 9 in concrete (Li 2011). Carbonation can be harmful if the reaction reaches the depth of steel reinforcement bars and the low pH accelerates corrosion (Klenke 2007). However, Ashraf found that carbonation could increase the compressive and tensile strength of concrete, which is beneficial to structures (Ashraf 2016). Phenolphthalein is commonly used to determine the depth of concrete carbonation. It is a pH indicator, which will change to pink or purple at the location of the concrete that has a pH value of 9 or more. Carbonation reaction causes a lower pH of 8.2 leading to a colorless section on the surface of the concrete sample where phenolphthalein is applied. In the 1990s, thermo-gravimetric analysis (TGA) was introduced as a more accurate method for the analysis of concrete carbonation (Klimesch and Ray 1997). In this chapter, concrete carbonation depth and rate are described by analyzing samples at different depths and exposure ages using TGA along with other techniques. 46 3.1 Carbonation Reaction The carbonation rate for concrete mainly depends on the concentration of CO2. Cui et al. found that a high concentration of CO2 in the surrounding environment of concrete would initially increase the carbonation rate; eventually, the CaCO3 fills up surface pores, causing the permeability and the subsequent carbonation rate to significantly decrease (Cui et al. 2015). Salvoldi et al. studied the relationship between oxygen permeability and carbonation and they found that carbonation rate decreases with the decrease of concrete permeability (Salvoldi et al. 2015). It was also found that the most important influence of RH is within the range of 50% to 70% (Ekolu 2016). It was also mentioned that a widelyused carbonation prediction equation is a logarithmic relation with time as shown in Equation (7) (Köliö et al. 2016; Salvoldi et al. 2015). 𝑥𝑥 = 𝑘𝑘 ∗ √𝑡𝑡 (7) where, 𝑥𝑥: carbonation depth, mm; 𝑘𝑘: carbonation coefficient, mm/yr; 𝑡𝑡: exposure time, yr. 3.2 TiO2 Properties TiO2 has been studied since 1960s as a photocatalytic material to reduce air pollutants (A. Fujishima 1969). TiO2 reacts with water in the air under UV light, generates H+ and OH- (Fujishima et al. 2000), which reacts with NO2 to purify air. 47 In recent years, researchers have applied titanium dioxide on construction materials such as concrete since this material covers a large portion of the earth's surface area (Ballari and Brouwers 2013; Chen and Poon 2009; Maggos et al. 2008; Shen et al. 2012). Researchers have noted that the measured TiO2 reactivity is reduced due to the carbonation reaction occurring in concrete (Chen and Poon 2009). Recently, studies have showed that the carbonation rate accelerates with the addition of Lime-TiO2 (Karatasios et al. 2010) and there is a decrease of carbonation for geopolymer specimens with the addition of TiO2 (Duan et al. 2016). In this study, the rate of and depth of carbonation for mortar mixtures is investigated, in particular to understand if a mortar specimen with a surface TiO2 coating, not just one containing embedded TiO2 particles, would have a different carbonation rate than plain concrete. Specimens were exposed in the natural outdoor environment and carbonation is quantified at 23, 59, and 100 days of weathering and at 5 mm increments from the exposed surface. The concentration of titanium dioxide was measured with a scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS). The carbonation amount was determined with TGA and mass spectrometry (MS). Although phenolphthalein is a traditional method, it does not give an accurate value for the carbonation depth or amount so it was not included in this study. 3.3 Methodology and Materials This study investigates the influence of a micron-size CristalACTiVTM P105 titanium dioxide powder added at 1% mass fraction of cementitious material, as well as a spray-on sol-gel solution composed of titanium dioxide called PURETi Coat. Both TiO2 materials 48 have been previously verified to be highly photocatalytic (Hanson 2014; Shen et al. 2012). A local ASTM C150 classified Type I/II/V cement from LaFarge Holcim's Devil's slide plant was used for this study along with a natural sand from Staker Parson's Beck street plant that meets the ASTM C33 standard. A polycarboxylate W.R. Grace's Advacast 575 high range water reducer was used to adjust the workability so all mixtures exhibited similar flow. Three batches of specimens were made in the University of Utah Concrete Lab by another graduate student 1. These samples consisted of a plain mortar, a PureTi coated mortar, and a TiO2 embedded in mortar. It was assumed the plain and PureTi samples contained the same mortar mixtures. Additionally, the TiO2 embedded specimens were prepared to have 1% of the total cementitious weight replaced by a TiO2 powder. The specimens were 2" x 4" cylinders (diameter of 2", height of 4") mixed and prepared by another graduate student1 in Fall 2015. The specimens all had a painted epoxy resin on the top and bottom of the cylinder to prevent carbonation from the ends and to have carbonation only in the horizontal radial direction. The specimens were said to be air cured in the lab for 7 days before exposure to the natural outdoor environment. The samples containing the spray-on TiO2 coating had two coats of the PURETi Coat applied at 4 days into the curing. The outside environment for storing the specimens was located on the white painted asphalt roof of MCE building as shown in Figure 18a. Specimens with the same TiO2 batch were placed roughly 2 inches apart on the roof as shown in Figure 18b; each set of the specimens from different TiO2 batches was kept at least 3 feet apart to avoid interaction between possible local air reactions. 1 Eight specimens are taken for Catalina Arboleda was in our research group and prepared these samples 49 measurement of carbonation depth at each testing age. The specimens collected are wrapped in plastic cling wrap to keep from further contact with air until tested. A CO2 exposure level data during the exposure period was obtained from University of Utah Atmospheric Trace Gas & Air Quality Lab (UATAQ Lab) as shown in Figure 19. A corresponding RH level from the Weather Underground Website (The Weather Company 2015) is shown in Figure 20. The average RH during this time frame was 45%. 3.4 Experiments 3.4.1 Verifying TiO2 Content To find the amount of TiO2 in the specimens, the EDS with a SEM in the University of Utah Nanofab Lab was used to map and quantify chemical elements on the surface of polished specimens. The sample preparation for SEM/EDS follows four different procedures: sawing, epoxying, polishing, and carbon coating (Goldstein 2003). Specimens were removed from the roof at ages 23, 59, and 100 days. Another graduate student 2 used a tile saw to cut an interior sample; cut samples were then stored in amber glass containers to prevent the exposure to UV lights, with ethanol to prevent additional hydration. For this research, after all the samples were collected, they were further prepared for use in the SEM/EDS analysis. Sample epoxy, polishing, and carbon-coating procedures are listed in Appendix H. An example of the final specimen used in the SEM/EDS can be seen in Figure 21. The FEI Quanta 600F SEM/EDS testing machine in the Utah Nanofab Surface Analysis Lab was used for mapping and chemical analysis. The general SEM settings 2 Catalina Arboleda cut those samples. 50 followed the Federal Highway Administration Research and Technology manual (Walker et al. 2006). The chamber pressure remained in default "HiVac" mode, which was about 1.93E-7 to 1.93E-8 psi. The SEM was used to identify the cement phases and avoid aggregate phases. Three different locations were selected from the cement locations to be analyzed with the EDS, since TiO2 was expected to only be mixed in cement phase. An example of the spot location identification is shown in Figure 22. At each of these spot locations, the magnification was increased approximately 1000x from the SEM image to perform the EDS analysis for a chemical composition map and quantification, shown in Figure 23 and Figure 24, respectively. It is possible that some of the sample locations may still have some small portion of fine aggregates included in the analysis. These can be seen in Figure 23 of each composition map, where there is an absence of calcium and a higher concentration of silica. 3.4.2 Carbonation Estimation Measurement for the carbonation depth was taken at roughly 23 days, 51-59 days, and between 92-100 days of exposure. The TGA was coupled with a mass spectrometry (MS) to analyze specifically the amount of carbon dioxide associated with the specimens. TGA is a micro-characterization technique that measures the simultaneous mass loss associated with chemical reactions or decomposition as the temperature rises. The differential thermo-gravimetric (DTG) measurement indicates the change in mass loss associated with specific temperatures. This is used to identify when specific decomposition, such as calcium hydroxide Ca(OH)2 or calcium carbonate, may be occurring in the concrete specimen. Synchronizing MS to the TGA/DTG allows us to 51 correlate the ion current while the sample is heated in the TGA, from which specific gases, such as water or carbon dioxide, can be measured as they leave the sample. The MS and TGA combined will both be used to confirm the quantity of CaCO3 found in the samples at various ages and depths. For the purposes of this research, it was assumed that the cement powder came from a cut piece from the interior of the cylinder, from which the cut sample was crushed and sieved to eliminate most of the sand particles for TGA analysis. The powder was stored in 2 mL amber glass vials until tested in the STD Q500 Simultaneous TGA/STD equipment in a University of Utah Chemistry Department laboratory. The temperature was set to increase at a rate of 20 °C/min from room temperature to 1000 °C. Li noted that at roughly 470 °C, Ca(OH)2 would burn off; anywhere from 700 °C to 1000 °C, it is expected that calcium silica hydrate and calcium carbonate would decompose, or possibly at these higher temperatures the CO2 might recombine with water (Li 2011). Taylor mentioned that the decomposition temperature of Ca(OH)2 is from 425 to 550 °C, while above 550 °C, the loss of CO2 and dehydration of calcium-silica-hydrate gel exist at the same time (Taylor 1997). From the DTG graph, the starting and ending points of these decompositions were identified from the graph, as shown in Figure 25 for TGA and Figure 26 for MS. The corresponding mass at each temperature or time for these boundary points was used to calculate the amount of material that burned off. Equation (8) and (9) show the calculation of Ca(OH)2 and CaCO3 amounts based on the mass loss and the original sample mass at room temperature. All the raw EDS results and TGA figures are shown in Appendix I and Appendix J, respectively. 52 𝐶𝐶𝐶𝐶(𝑂𝑂𝑂𝑂)2 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 = 74.1×𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊ℎ𝑡𝑡 𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 18×𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊ℎ𝑡𝑡 (8) where, 74.1 is the molar weight of Ca(OH)2, 18 is the molar weight of water. 𝐶𝐶𝑎𝑎𝑎𝑎𝑎𝑎3 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 = 100.1×𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊ℎ𝑡𝑡 𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 44×𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊ℎ𝑡𝑡 (9) where, 100.1 is the molar weight of CaCO3, 44 is the molar weight of CO2. 3.5 Results 3.5.1 Chemistry Composition The analysis from the SEM/EDS verified that there were negligible quantities of titanium dioxide found in the plain concrete samples and PureTi coated samples. The 1% TiO2 samples were verified to contain around 0.79% on average of TiO2, as shown in Table 19. 3.5.2 Carbonation Quantity The carbonation quantity results were obtained and analyzed by the calculation from TGA/MS figures and the two equations mentioned before. To analyze the carbonation, CaCO3 estimation figures along with exposure age and tested depth were created as shown in Figure 27 and Figure 28, respectively. Figure 27 showed the carbonation amount versus age. Based on TGA and MS results 53 at 5 mm depth, carbonation amount increased gradually with age; at 15 mm depth, the amount of carbonation remains at low regardless of age. Comparing the carbonation for different specimens, those with photocatalytic materials indicated even more carbonation on the surface at the later age than plain concrete. This affirms the hypothesis indicating that carbonation is greater with TiO2. When analyzing the carbonation amount versus depth in Figure 28, the carbonation amount decreases with depth but is still higher at longer exposure ages. By the 90 to 100 days' exposure age, carbonation amount is higher for those specimens containing TiO2 than plain mortar. 3.6 Summary and Findings The study was focused on the carbonation depth and rate of mortar in the presence of a photocatalytic material. SEM/EDS were used to confirm the amount of embedded TiO2, and TGA/DTG and MS were used for carbonation quantity analysis. From the analyzed results, plain concrete mortar samples had less carbonation even in a long exposure age compared with mortar samples with photocatalytic TiO2 either embedded or sprayed on. Carbonation was confirmed to be higher near the sample surface and at later ages. The results may lead to a possible demand for carbonation-resistant mix designs, precarbonated mixtures, or alternative backing construction materials for the application of TiO2 in the future. By negating the influence of new carbonation on TiO2 surfaces, the reactivity for reducing smog by the TiO2 is expected to be long-lasting. 54 Table 19 Percentage Amount of TiO2 Based on EDS of Three Locations Age (Days) Minimum Maximum Overall Average Plain Concrete 59 100 0% 0% 0% 0% 0% PureTi 59 0% 0% 1% TiO2 100 0% 0% 0% 51 92 0.65% 0.74% 0.79% 0.96% 0.79% 55 a) b) North CO2 Concentration (ppm) Figure 18. a) Location on Roof Where Samples Were Stored During Exposure to Outside Environment. Image from Google maps. b) Arrangement of Cylindrical Samples of Similar Mix Design at Each Location. 520 500 480 460 440 420 400 380 7/15/2015 8/4/2015 8/24/2015 9/13/2015 Time (Days) 10/3/2015 10/23/2015 Figure 19. Daily CO2 Exposure Level in University of Utah from UATAQ Lab 56 RH Level (%) 100 80 60 40 20 0 7/15/2015 8/4/2015 8/24/2015 9/13/2015 10/3/2015 10/23/2015 Time (Days) Figure 20. Environmental RH Level During Exposure Days Figure 21. Photograph Sample After Epoxy-impregnation for SEM/EDS Analysis. 57 Spot 2 Figure 22. Example of an SEM Secondary Electron and Back-scatter Electron Image for Selecting a Spot in the Cement Phase. The Sample Shown Represents Spot 2 on the 1% TiO2 Specimen. Secondary Electron Ca C Fe Al K Mg N a O S Si Ti Figure 23. Map of Each Chemical Element Distributed on the Surface of the Spot Image, Superimposed on the Secondary Electron Image. Sample Shown Is from Spot 1 of the 1% TiO2 Specimen. 58 Figure 24. Example of the EDS Analysis Output Showing Quantities of Each Chemical Element Found for Spot 1 of the 1% TiO2 Specimen 0.20 101% 0.15 TGA (%mass) 99% TGA (%mass) 97% 0.05 CaCO3 DTG (%mass/ºC) 0.00 95% -0.05 93% DTA Signal (%mass/ºC) 0.10 Ca(OH)2 -0.10 91% -0.15 89% 0 100 200 300 400 500 600 Temperature (ºC) 700 800 900 -0.20 1000 Figure 25. TGA and DTG Plot Along with Indication of Temperatures Selected to Determine Mass Loss. Sample Shown Is from the Top 5 mm of the Plain Concrete After 100-days Exposure. 59 5.0 101% CO2 TGA 4.5 99% 4.0 TGA (%mass) 3.0 CO2 95% 2.5 2.0 93% 1.5 1.0 91% 0.5 H2O 89% 0.0 0 10 20 30 Time (min) 40 50 60 Figure 26. Mass Spectroscopy Plot Along with Indication of Times Selected to Determine Mass Loss. Sample Shown Is from the Top 5 mm of the Plain Concrete After 100-days Exposure. Ion Current (A) 3.5 97% 60 30% b) 30% CaCO3 Estimate from TGA (At 15mm Depth) CaCO3 Estimate from TGA (At 5mm Depth) a) 25% 20% 15% 10% 5% 25% 20% 15% PureTi Coating 10% 0% 50 100 Age (Days) 150 0 d) CaCO3 Estimate from MS (At 15mm Depth) 30% CaCO3 Estimate from MS (At 5mm Depth) TiO2 embedded 1% 5% 0% 0 c) Plain 25% 20% 15% 10% 5% 0% 100 200 Age (Days) 30% 25% 20% Plain 15% PureTi Coating 10% TiO2 embedded 1% 5% 0% 0 50 100 Age (Days) 150 0 100 200 Age (Days) Figure 27. Carbonation Amount versus Age Based on a) and b) TGA; c) and d) MS 61 30% 30% b) CaCO3 Estimate from TGA (Aat 90-100 Days) CaCO3 Estimate from TGA (At 23 Days) a) 25% 20% 15% 10% 5% 25% 20% 15% PureTi Coating 10% 0% 10 Depth (mm) 20 30% 0 d) CaCO3 Estimate from MS (At 90-100 Days) CaCO3 Estimate from MS (At 23 Days) TiO2 embedded 1% 5% 0% 0 c) Plain 25% 20% 15% 10% 5% 0% 10 20 Depth (mm) 30% 25% 20% Plain 15% PureTi Coating 10% TiO2 embedded 1% 5% 0% 0 10 Depth (mm) 20 0 10 20 Depth (mm) Figure 28. Carbonation Amount versus Depth Based on a) and b) TGA; c) and d) MS CHAPTER 4 CONCLUSION 4.1 Conclusions and Suggestions Two specific cases regarding shrinkage and carbonation were investigated to find out the influence from environmental conditions on mortar mixtures. As for the prevention of concrete distresses, the environmental exposure was found to be a dominant influence on shrinkage, and with the combination of other chemical reactions from TiO2, this environmental effect may be enhanced. Regarding mortar shrinkage, it is observed that a high humidity environment will be ideal for lowest shrinkage since concrete loses less water in a highly humid environment. This study found the existing standard 1" prism sizes (with a high surface area to volume ratio) had the least amount of shrinkage compared to 2" and 3" prism sizes, while 3" prisms are less sensitive to different humidity environments. Two concrete shrinkage prediction models were also used for the comparison between the predicted and measured shrinkage values; it was found ACI committee 209 prediction model has a lower overall sum of squared error when predicting shrinkage in the 50% humidity chamber storage. The Moon and Weiss model had a lower sum of squared error for predicting shrinkage in a 5% humidity refrigerator storage. Overall, future laboratory testing parameters can be selected and recommended to reduce variation in measured shrinkage values from 63 different laboratory storage environments. From the carbonation study, mortars with TiO2 photocatalytic materials embedded or applied to the surface were both found and confirmed to have more carbonation amount near the surface and at long exposure ages compared to mortar without TiO2. Although carbonation may be beneficial to protect the interior mortar and increase strength, the faster rate of carbonation with the TiO2 may lead to sooner reduced efficiency in the photocatalytic capability and can also lead to sooner corrosion of any interior steel. 4.2 Further Studies These studies were only two specific cases regarding concrete distress. However, this study has limitations regarding the concrete shrinkage: the temperature influences and different water/cement ratios for shrinkage were not studied in this thesis. For the carbonation study, the traditional phenolphthalein method was not analyzed for comparison with the TGA and MS methods used to confirm the carbonation trends. Furthermore, only a small amount of samples was measured for the carbonation study so no statistical analysis can be concluded now. A recommendation for additional shrinkage tests would be to have more replicates of the specimens for a more precise statistical result. A moist curing age from 0 to 28 days can be varied, as well as different water/cement ratios and other mixture proportions could also be studied. A study regarding concrete with coarse aggregates could also be created to understand the concrete shrinkage effect at different environments. Additional studies for the carbonation tests include performing a strength test at each age to see if the TiO2 also effects strength along with carbonation rate. More samples 64 could be tested at each age and each depth for a better statistical analysis to be calculated. Furthermore, the phenolphthalein method could be used for verification of the carbonation rate trend seen. APPENDIX A TEMPERATURE, %RH, AND DAILY FLUCTUATION FIGURES In Appendix A, the temperature and relative humidity data for all storing locations recorded every 10 minutes through whole storing time was plotted, as well as the daily temperature and humidity fluctuation. 35 120 30 Temperature (ºC) 100 80 20 60 15 40 10 5 0 7/28/2016 Humidity (%RH) 20 0 8/4/2016 8/11/2016 Date Figure 29. Temperature and Humidity Data in Fume Hood Humidity (%) Temperature (∘C) 25 66 35 120 30 100 Temperature (ºC) 80 20 60 15 Humidity (%RH) Humidity (%) Temperature (∘C) 25 40 10 20 5 0 5/25/2016 6/1/2016 6/8/2016 6/15/2016 6/22/2016 0 6/29/2016 Date Figure 30. Temperature and Humidity Data in Storage Room 130C 35 120 Temperature (ºC) 30 100 80 20 60 15 40 10 20 5 0 5/25/2016 Humidity (%RH) 6/1/2016 6/8/2016 6/15/2016 6/22/2016 Date Figure 31. Temperature and Humidity Data in Room 110A 0 6/29/2016 Humidity (%) Temperature (∘C) 25 67 35 120 Temperature (ºC) 30 100 80 20 15 60 Humidity (%RH) Humidity (%) Temperature (∘C) 25 40 10 20 5 0 5/25/2016 6/1/2016 6/8/2016 6/15/2016 6/22/2016 0 6/29/2016 Date Figure 32. Temperature and Humidity Data in Fog Room 35 120 30 Temperature (ºC) 100 80 20 60 15 40 10 Humidity (%RH) 20 5 0 7/15/2016 0 7/25/2016 8/4/2016 8/14/2016 8/24/2016 Date Figure 33. Temperature and Humidity Data in UDOT Humidity (%) Temperature (∘C) 25 68 a) 35 30 Temperature (∘C) 25 20 15 10 5 0 6/11/16 6/18/16 6/25/16 7/2/16 7/9/16 7/16/16 7/23/16 7/30/16 7/16/16 7/23/16 7/30/16 Date b) 100 Humidity (%RH) 80 60 40 20 0 6/11/16 6/18/16 6/25/16 7/2/16 7/9/16 Date Figure 34. Daily a) Temperature and b) Humidity Fluctuation in Refrigerator 69 a) 35 30 Temperature (∘C) 25 20 15 10 5 0 7/28/16 8/4/16 8/11/16 Date b) 100 Humidity (%) 80 60 40 20 0 7/28/16 8/4/16 8/11/16 Date Figure 35. Daily a) Temperature and b) Humidity Fluctuation in Fume Hood 70 a) 35 30 Temperature (∘C) 25 20 15 10 5 0 5/25/16 6/1/16 6/8/16 6/15/16 6/22/16 6/29/16 7/6/16 7/13/16 7/20/16 7/27/16 7/6/16 7/13/16 7/20/16 7/27/16 Date b) 100 Humidity (%) 80 60 40 20 0 5/25/16 6/1/16 6/8/16 6/15/16 6/22/16 6/29/16 Date Figure 36. Daily a) Temperature and b) Humidity Fluctuation in Storage Room 130C 71 a) 35 30 Temperature (∘C) 25 20 15 10 5 0 5/25/16 6/1/16 6/8/16 6/15/16 6/22/16 6/29/16 7/6/16 7/13/16 7/20/16 7/27/16 7/6/16 7/13/16 7/20/16 7/27/16 Date b) 100 Humidity (%) 80 60 40 20 0 5/25/16 6/1/16 6/8/16 6/15/16 6/22/16 6/29/16 Date Figure 37. Daily a) Temperature and b) Humidity Fluctuation in Room 110A 72 a) 35 30 Temperature (∘C) 25 20 15 10 5 0 7/14/16 7/21/16 7/28/16 8/4/16 8/11/16 8/18/16 8/25/16 8/11/16 8/18/16 8/25/16 Date b) 100 Humidity (%) 80 60 40 20 0 7/14/16 7/21/16 7/28/16 8/4/16 Date Figure 38. Daily a) Temperature and b) Humidity Fluctuation in UDOT 73 a) 35 30 Temperature (∘C) 25 20 15 10 5 0 5/25/16 6/1/16 6/8/16 6/15/16 6/22/16 6/29/16 7/6/16 7/13/16 7/20/16 7/27/16 7/6/16 7/13/16 7/20/16 7/27/16 Date b) 100 Humidity (%) 80 60 40 20 0 5/25/16 6/1/16 6/8/16 6/15/16 6/22/16 6/29/16 Date Figure 39. Daily a) Temperature and b) Humidity Fluctuation in Fog Room APPENDIX B OVEN DRY (OD) BATCH AMOUNT Table 20 Oven Dry Mix Design Mix Date Materials Batch 1 May 24th Batch 2 Jun 2nd Batch 3 Jun 8th Batch 4 Jun 21st Batch 5 July 18th Batch in mass Batch in mass Batch in mass Batch in mass Batch in mass OD (lb) ratios OD (lb) ratios OD (lb) ratios OD (lb) ratios OD (lb) ratios Type II Cement 43.50 Natural Sand 52.25 Water 24.00 1.00 1.20 0.55 42.76 48.82 23.55 1.00 1.14 0.55 46.32 52.89 25.51 1.00 1.14 0.55 46.32 52.89 25.51 1.00 1.14 0.55 114.06 130.23 62.80 1.00 1.14 0.55 APPENDIX C TESTING DATES Table 21 Testing and Measurements Date Measuring Time Mix 1 Mix 2 Humidity Chamber, Storage Room 130C, Refrigerator, Fog Room 110A Fume Hood Room 130D Humidity Chamber, Fume Hood UDOT Cast 5/24/16 11:00 6/2/16 10:30 6/8/16 11:00 6/21/16 12:30 7/18/16 12:30 .5 days 5/24/16 23:00 6/2/16 23:00 6/8/16 23:00 6/22/16 0:40 7/19/16 0:30 1 day 5/25/16 11:00 6/3/16 12:42 6/9/16 11:49 6/22/16 12:45 7/19/16 12:40 3 days 5/27/16 10:58 6/5/16 12:33 6/11/16 13:00 6/24/16 12:35 7/21/16 12:38 7 days 5/31/16 12:00 6/9/16 12:20 6/15/16 10:58 6/28/16 11:40 7/25/16 12:16 14 days 6/7/16 10:07 6/16/16 11:03 6/22/16 12:20 7/5/16 12:30 8/1/16 12:32 21 days 6/14/16 11:47 6/23/16 11:30 6/29/16 12:15 7/12/16 12:38 8/8/16 12:40 28 days 6/21/16 13:00 6/30/16 13:49 7/6/16 13:07 7/19/16 12:30 8/15/16 14:15 56 days 7/19/16 11:05 7/28/16 12:11 8/3/16 13:20 8/16/16 12:00 9/12/16 12:14 APPENDIX D SHRINKAGE RELATIVE TO HUMIDITY CHAMBER Shrinkage Relative to Humidity Chamber (10-6 in/in) 600 Humidity Chamber 400 Fume Hood NDT 200 Clean Room 0 UDOT Log. (Fume Hood) -200 Log. (NDT) Log. (Clean Room) -400 0 20 40 Time (Days) 60 Log. (UDOT) Figure 40. Relative Shrinkage of Samples in Alternative Storage Environments Subtracted from the Average Shrinkage of Samples in the Humidity Chamber APPENDIX E SHRINKAGE AND WEIGHT CHANGE FIGURES 2200 2000 Shrinkage (10-6 in/in) 1800 1600 1400 1200 1000 800 600 400 200 0 -200 0 10 20 30 40 Time (Days) 50 60 1x1x10" prism 1x1x10" prism 1x1x10" prism 1x1x10" prism 2x2x10" prism 2x2x10" prism 2x2x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism Figure 41. Shrinkage versus Time for Mix 1 Stored in Humidity Chamber 78 2200 2000 Shrinkage (10-6 in/in) 1800 1600 1400 1200 1000 800 600 400 200 0 -200 0 10 20 30 40 Time (Days) 50 60 1x1x10" prism 1x1x10" prism 1x1x10" prism 1x1x10" prism 2x2x10" prism 2x2x10" prism 2x2x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism Figure 42. Shrinkage versus Time for Mix 1 Stored in Fume Hood 2200 Shrinkage (10-6 in/in) 2000 1800 1x1x10" prism 1600 1x1x10" prism 1400 1x1x10" prism 1200 1x1x10" prism 1000 2x2x10" prism 800 2x2x10" prism 600 2x2x10" prism 400 3x3x10" prism 200 3x3x10" prism 0 3x3x10" prism -200 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 43. Shrinkage versus Time Stored in Refrigerator (Mix 2) 79 2200 Shrinkage (10-6 in/in) 2000 1800 1x1x10" prism 1600 1x1x10" prism 1400 1x1x10" prism 1200 1x1x10" prism 1000 2x2x10" prism 800 2x2x10" prism 600 2x2x10" prism 400 3x3x10" prism 200 3x3x10" prism 0 3x3x10" prism -200 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 44. Shrinkage versus Time Stored in Humidity Chamber (Mix 2) 2200 Shrinkage (10-6 in/in) 2000 1800 1x1x10" prism 1600 1x1x10" prism 1400 1x1x10" prism 1200 1x1x10" prism 1000 2x2x10" prism 800 2x2x10" prism 600 2x2x10" prism 400 3x3x10" prism 200 3x3x10" prism 0 3x3x10" prism -200 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 45. Shrinkage versus Time Stored in Fume Hood (Mix 2) 80 2200 2000 Shrinkage (10-6 in/in) 1800 1600 1400 1200 1000 800 600 400 200 0 -200 0 10 20 30 40 Time (Days) 50 60 1x1x10" prism 1x1x10" prism 1x1x10" prism 1x1x10" prism 2x2x10" prism 2x2x10" prism 2x2x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism Figure 46. Shrinkage versus Time Stored in Storage Room 130C (Mix 2) 2200 2000 Shrinkage (10-6 in/in) 1800 1600 1400 1200 1000 800 600 400 200 0 -200 0 10 20 30 40 Time (Days) 50 60 1x1x10" prism 1x1x10" prism 1x1x10" prism 1x1x10" prism 2x2x10" prism 2x2x10" prism 2x2x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism Figure 47. Shrinkage versus Time Stored in Room 110A (Mix 2) 81 2200 2000 Shrinkage (10-6 in/in) 1800 1600 1400 1200 1000 800 600 400 200 0 -200 0 10 20 30 40 Time (Days) 50 60 1x1x10" prism 1x1x10" prism 1x1x10" prism 1x1x10" prism 2x2x10" prism 2x2x10" prism 2x2x10" prism 2x2x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism 3x3x10" prism Figure 48. Shrinkage versus Time Stored in UDOT Lab (Mix 2) 2200 Shrinkage (10-6 in/in) 2000 1800 1x1x10" prism 1600 1x1x10" prism 1400 1x1x10" prism 1200 1x1x10" prism 1000 2x2x10" prism 800 2x2x10" prism 600 2x2x10" prism 400 3x3x10" prism 200 3x3x10" prism 0 3x3x10" prism -200 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 49. Shrinkage versus Time Stored in Fog Room (Mix 2) 82 Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 50. Weight Reduction for Mix 1 Stored in Humidity Chamber Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 51. Weight Reduction for Mix 1 Stored in Fume Hood 83 Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 52. Weight Reduction for Samples Stored in Refrigerator (Mix 2) Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 53. Weight Reduction for Samples Stored in Humidity Chamber (Mix 2) 84 Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 54. Weight Reduction for Samples Stored in Fume Hood (Mix 2) Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% -2% 0 -4% 10 20 30 40 50 60 3x3x10" prism 3x3x10" prism Time (Days) Figure 55. Weight Reduction for Samples Stored in Storage Room 130C (Mix 2) 85 Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 56. Weight Reduction for Samples Stored in Room 110A (Mix 2) 20% 1x1x10" prism Weight Reduction (%) 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 2x2x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism 3x3x10" prism Figure 57. Weight Reduction for Samples Stored in UDOT Lab (Mix 2) 86 Weight Reduction (%) 20% 18% 1x1x10" prism 16% 1x1x10" prism 14% 1x1x10" prism 12% 1x1x10" prism 10% 2x2x10" prism 8% 2x2x10" prism 6% 2x2x10" prism 4% 3x3x10" prism 2% 3x3x10" prism 0% 3x3x10" prism 0 10 20 30 40 Time (Days) 50 60 3x3x10" prism Figure 58. Weight Reduction for Samples Stored in Fog Room (Mix 2) APPENDIX F SHRINKAGE PREDICTION PER ACI COMMITTEE 209 In this appendix, shrinkage prediction parameters and comparison between predicted and measured shrinkage values will be listed by following ACI Committee 209 equations. 88 Table 22 Prediction Parameters Per ACI Committee 209 Mix Locations Fume Hood Mix 1 Humidity Chamber Refrigerator Humidity Chamber Fume Hood Mix 2 Storage Room 130C Room 110A UDOT Fog Room Dimensions 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 𝛾𝛾ℎ 𝛾𝛾𝑐𝑐𝑐𝑐 1 2 1 2 1 2 0.89 2 0.89 2 0.89 2 1 2 1 2 1 2 0.89 2 0.89 2 0.89 2 1 2 1 2 1 2 0.84 2 0.84 2 0.84 2 1 2 1 2 1 2 0.96 2 0.96 2 0.96 2 0 2 0 2 0 2 𝛾𝛾𝑡𝑡ℎ 𝛾𝛾𝑠𝑠 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 1.43 1 1.30 1 1.17 1 𝛾𝛾𝑓𝑓 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 𝛾𝛾𝑒𝑒 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 𝛾𝛾𝑐𝑐 1.36 1.36 1.36 1.36 1.36 1.36 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 1.22 𝛾𝛾𝑉𝑉⁄𝑆𝑆 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 1.17 1.14 1.11 𝛾𝛾𝑠𝑠ℎ 4.99 4.42 3.88 4.44 3.93 3.46 4.48 3.96 3.48 3.98 3.53 3.10 4.48 3.96 3.48 3.76 3.33 2.92 4.48 3.96 3.48 4.30 3.81 3.35 0.00 0.00 0.00 89 Table 23 Predicted Values, Measured Values, Error, and Squared Error for All Samples at All Ages (ACI Committee 209 Equations) Ages 3 7 Mix Locations Sizes P* M E SE P M E SE 1" 307 865 558 310897 649 1465 816 665864 Fume Hood 2" 272 263 -9 79 575 817 242 58579 3" 239 183 -57 3203 505 510 5 28 1 1" 274 787 513 263235 578 983 406 164615 Humidity 2" 242 247 4 19 511 620 109 11788 Chamber 3" 213 128 -85 7275 449 385 -64 4125 1" 276 210 -66 4317 582 735 153 23396 Refrigerator 2" 244 193 -51 2579 515 437 -79 6192 3" 214 150 -64 4151 453 320 -133 17604 1" 245 803 558 311316 518 983 465 216520 Humidity 2" 217 470 253 63876 459 797 338 114246 Chamber 3" 191 398 207 42708 403 710 307 94320 1" 276 1088 812 659013 582 1175 593 351600 Fume Hood 2" 244 587 343 117342 515 977 461 212810 3" 214 375 161 25784 453 625 172 29695 1" 231 573 341 116407 488 1013 524 274751 Storage Room 2 2" 205 230 25 634 432 567 134 18033 130C 3" 180 147 -32 1050 380 370 -10 96 1" 276 1070 794 630906 582 1363 781 610417 Room 110A 2" 244 443 199 39688 515 923 408 166448 3" 214 270 56 3088 453 547 94 8834 1" 265 525 260 67568 560 1248 688 473241 UDOT 2" 235 277 42 1762 495 723 228 51926 3" 206 178 -29 821 435 430 -5 27 1" 0 105 105 11025 0 120 120 14400 Fog Room 2" 0 113 113 12844 0 183 183 33611 3" 0 92 92 8556 0 190 190 36100 * P, M, E, SE stand for predicted values, measured values, error, and squared error. 90 Table 23 Continued Mix Locations Fume Hood 1 Humidity Chamber Refrigerator Humidity Chamber Fume Hood 2 Storage Room 130C Room 110A UDOT Fog Room Ages 14 Sizes P M E 1" 1113 1628 515 2" 985 1197 212 3" 865 910 45 1" 990 1210 220 2" 877 953 77 3" 770 687 -83 1" 998 1363 365 2" 883 750 -133 3" 776 527 -249 1" 888 1103 215 2" 786 1047 260 3" 691 998 307 1" 998 1225 227 2" 883 1237 353 3" 776 958 181 1" 837 1290 453 2" 741 870 129 3" 651 588 -64 1" 998 1420 422 2" 883 1203 320 3" 776 857 81 1" 959 1440 481 2" 849 1063 214 3" 746 695 -51 1" 0 255 255 2" 0 263 263 3" 0 253 253 SE 265160 44765 1999 48320 5868 6824 133017 17812 62177 46356 67800 94152 51627 124753 32935 205081 16583 4043 178265 102317 6504 231101 45784 2608 65025 69344 63756 P 1460 1293 1136 1300 1151 1011 1310 1160 1019 1166 1032 906 1310 1160 1019 1099 973 855 1310 1160 1019 1259 1115 979 0 0 0 M 1598 1290 1085 1253 1067 843 1655 1070 747 1257 1237 1223 1398 1443 1235 1488 1083 810 1450 1327 1057 1560 1277 868 295 317 325 21 E 137 -3 -51 -46 -84 -168 345 -90 -272 91 205 316 88 284 216 389 110 -45 140 167 38 301 162 -112 295 317 325 SE 18841 9 2570 2142 7063 28313 119306 8018 73908 8304 41891 99863 7728 80536 46861 151128 12205 1984 19714 27930 1455 90575 26205 12479 87025 100278 105625 91 Table 23 Continued Mix Locations Fume Hood 1 Humidity Chamber Refrigerator Humidity Chamber Fume Hood 2 Storage Room 130C Room 110A UDOT Fog Room Ages Sizes 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 28 P 1731 1532 1346 1540 1364 1198 1552 1374 1207 1381 1223 1074 1552 1374 1207 1302 1153 1013 1552 1374 1207 1492 1321 1161 0 0 0 M 1713 1397 1213 1343 1170 1005 1768 1290 920 1293 1293 1340 1258 1297 1148 1488 1147 888 1480 1413 1207 1695 1460 1020 200 247 247 E -18 -136 -134 -197 -194 -193 215 -84 -287 -88 70 266 -295 -78 -60 185 -6 -125 -72 39 0 203 139 -141 200 247 247 SE 330 18413 17823 38789 37559 37227 46393 7102 82451 7752 4932 70566 86795 6023 3557 34329 40 15698 5200 1526 0 41128 19258 19754 40000 60844 61256 P 2396 2122 1864 2133 1888 1659 2149 1903 1671 1913 1694 1488 2149 1903 1671 1803 1596 1402 2149 1903 1671 2066 1829 1607 0 0 0 M 1670 1420 1388 1413 1257 1190 1918 1703 1390 1393 1367 1505 1393 1483 1413 1615 1320 1120 1570 1557 1470 1905 1787 1385 250 287 277 56 E -726 -702 -476 -719 -632 -469 -232 -200 -281 -519 -327 17 -757 -420 -259 -188 -276 -282 -579 -346 -201 -161 -43 -222 250 287 277 SE 527497 492428 226765 517486 399013 219671 53627 39804 79202 269718 106840 304 572407 175988 67044 35372 76444 79709 335329 119838 40573 25960 1826 49245 62500 82178 77006 92 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 59. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Refrigerator at All Ages (ACI Committee 209) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 60. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Fume Hood at All Ages (ACI Committee 209) 93 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 61. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Storage Room 130C at All Ages (ACI Committee 209) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 62. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Room 110A at All Ages (ACI Committee 209) 94 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 63. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Room 110A at All Ages (ACI Committee 209) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 64. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Fog Room at All Ages (ACI Committee 209) 95 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 65. Comparison Between Predicted and Measured Shrinkage Values for Mix 1 Samples Stored in Fume Hood at All Ages (ACI Committee 209) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 66. Comparison Between Predicted and Measured Shrinkage Values for Mix 1 Samples Stored in Humidity Chamber at All Ages (ACI Committee 209) APPENDIX G SHRINKAGE PREDICTION PER MOON AND WEISS In this appendix, shrinkage prediction parameters and comparison between predicted and measured shrinkage values will be listed by following Moon and Weiss diffusion equations. 97 Table 24 Prediction Parameters (Moon and Weiss) Mix 1 2 𝛾𝛾ℎ 1 Fume Hood 1 1 0.89 Humidity 0.89 Chamber 0.89 1 Refrigerator 1 1 0.89 Humidity 0.89 Chamber 0.89 1 Fume Hood 1 1 0.839 Storage 0.839 Room 130C 0.839 1 Room 110A 1 1 0.9614 UDOT 0.9614 0.9614 0 Fog Room 0 0 Locations 𝛾𝛾𝑐𝑐𝑐𝑐 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 𝛾𝛾𝑠𝑠 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 𝛾𝛾𝑓𝑓 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1 𝛾𝛾𝑒𝑒 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 𝛾𝛾𝑐𝑐 Shrinkage Coefficient 1.36 2335 1.36 2335 1.36 2335 1.36 2335 1.36 2335 1.36 2335 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 1.22 2094 98 Table 25 Internal RH and Delta RH at Specific Depths and Ages Mix Locations Fume Hood 1 Humidity Chamber Refrigerator Humidity Chamber Fume Hood 2 Storage Room 130C Room 110A UDOT Fog Room Age Sizes 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 3 Depth 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 0.5 1 1.5 RH(x,t) 0.899 0.997 1.000 0.922 0.998 1.000 0.853 0.996 1.000 0.922 0.998 1.000 0.899 0.997 1.000 0.930 0.998 1.000 0.890 0.997 1.000 0.912 0.997 1.000 1.000 1.000 1.000 7 ∆𝑅𝑅𝑅𝑅 RH(x,t) ∆𝑅𝑅𝑅𝑅 0.101 0.771 0.229 0.003 0.959 0.041 0.000 0.997 0.003 0.078 0.824 0.176 0.002 0.969 0.031 0.000 0.997 0.003 0.147 0.666 0.334 0.004 0.940 0.060 0.000 0.995 0.005 0.078 0.824 0.176 0.002 0.969 0.031 0.000 0.997 0.003 0.101 0.771 0.229 0.003 0.959 0.041 0.000 0.997 0.003 0.070 0.842 0.158 0.002 0.972 0.028 0.000 0.998 0.002 0.110 0.750 0.250 0.003 0.955 0.045 0.000 0.996 0.004 0.088 0.799 0.201 0.003 0.964 0.036 0.000 0.997 0.003 0.000 1.000 0.000 0.000 1.000 0.000 0.000 1.000 0.000 14 RH(x,t) ∆𝑅𝑅𝑅𝑅 0.668 0.332 0.878 0.122 0.969 0.031 0.745 0.255 0.906 0.094 0.976 0.024 0.515 0.485 0.821 0.179 0.954 0.046 0.745 0.255 0.906 0.094 0.976 0.024 0.668 0.332 0.878 0.122 0.969 0.031 0.770 0.230 0.915 0.085 0.978 0.022 0.638 0.362 0.866 0.134 0.966 0.034 0.709 0.291 0.893 0.107 0.972 0.028 1.000 0.000 1.000 0.000 1.000 0.000 99 Table 25 Continued Mix Locations Fume Hood 1 Humidity Chamber Refrigerator Humidity Chamber Fume Hood 2 Storage Room 130C Room 110A UDOT Fog Room Age Sizes 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 1" 2" 3" 21 28 56 Depth RH(x,t) ∆𝑅𝑅𝑅𝑅 RH(x,t) ∆𝑅𝑅𝑅𝑅 RH(x,t) ∆𝑅𝑅𝑅𝑅 0.5 0.616 0.384 0.583 0.417 0.518 0.482 1 0.816 0.184 0.771 0.229 0.668 0.332 1.5 0.930 0.070 0.894 0.106 0.790 0.210 0.5 0.704 0.296 0.679 0.321 0.629 0.371 1 0.859 0.141 0.824 0.176 0.745 0.255 1.5 0.947 0.053 0.919 0.081 0.838 0.162 0.5 0.439 0.561 0.390 0.610 0.295 0.705 1 0.732 0.268 0.666 0.334 0.515 0.485 1.5 0.898 0.102 0.845 0.155 0.693 0.307 0.5 0.704 0.296 0.679 0.321 0.629 0.371 1 0.859 0.141 0.824 0.176 0.745 0.255 1.5 0.947 0.053 0.919 0.081 0.838 0.162 0.5 0.616 0.384 0.583 0.417 0.518 0.482 1 0.816 0.184 0.771 0.229 0.668 0.332 1.5 0.930 0.070 0.894 0.106 0.790 0.210 0.5 0.734 0.266 0.711 0.289 0.666 0.334 1 0.873 0.127 0.842 0.158 0.770 0.230 1.5 0.952 0.048 0.927 0.073 0.854 0.146 0.5 0.580 0.420 0.544 0.456 0.473 0.527 1 0.799 0.201 0.750 0.250 0.638 0.362 1.5 0.924 0.076 0.884 0.116 0.770 0.230 0.5 0.663 0.337 0.634 0.366 0.577 0.423 1 0.839 0.161 0.799 0.201 0.709 0.291 1.5 0.939 0.061 0.907 0.093 0.816 0.184 0.5 1.000 0.000 1.000 0.000 1.000 0.000 1 1.000 0.000 1.000 0.000 1.000 0.000 1.5 1.000 0.000 1.000 0.000 1.000 0.000 100 Table 26 Predicted Values, Measured Values, Error, and Squared Error for All Samples at All Ages (Moon and Weiss) Ages 3 7 Mix Locations Sizes P* M E SE P M E SE 1" 235 865 630 396315 534 1465 931 866146 Fume Hood 2" 7 263 257 65822 95 817 722 520581 3" 0 183 182 33295 8 510 502 252056 1 1" 181 787 606 366679 411 983 572 327539 Humidity 2" 5 247 241 58300 73 620 547 298996 Chamber 3" 0 128 127 16250 6 385 379 143554 1" 309 210 -99 9729 700 735 35 1199 Refrigerator 2" 9 193 184 34022 125 437 312 97309 3" 0 150 150 22488 10 320 310 95841 1" 162 803 641 410744 369 983 615 377873 Humidity 2" 5 470 465 216528 66 797 731 534394 Chamber 3" 0 398 397 157990 5 710 705 496344 1" 211 1088 876 767950 479 1175 696 484129 Fume Hood 2" 6 587 581 337084 85 977 891 794469 3" 0 375 375 140605 7 625 618 381765 1" 146 573 426 181735 332 1013 681 463410 Storage 2 2" 4 230 226 50982 59 567 508 257645 Room 130C 3" 0 147 147 21751 5 370 365 133272 1" 231 1070 839 704482 523 1363 840 705420 Room 110A 2" 7 443 437 190703 93 923 830 689098 3" 0 270 270 72884 8 547 539 290392 1" 185 525 340 115476 420 1248 827 684381 UDOT 2" 5 277 271 73624 75 723 648 420552 3" 0 178 177 31498 6 430 424 179563 1" 0 105 105 11025 0 120 120 14400 Fog Room 2" 0 113 113 12844 0 183 183 33611 3" 0 92 92 8556 0 190 190 36100 * P, M, E, SE stand for predicted values, measured values, error, and squared error. 101 Table 26 Continued Mix Locations Fume Hood 1 Humidity Chamber Refrigerator Humidity Chamber Fume Hood 2 Storage Room 130C Room 110A UDOT Fog Room Ages 14 Sizes P M E 1" 775 1628 853 2" 286 1197 911 3" 73 910 837 1" 596 1210 614 2" 220 953 734 3" 56 687 631 1" 1016 1363 347 2" 374 750 376 3" 96 527 430 1" 535 1103 569 2" 197 1047 850 3" 51 998 947 1" 695 1225 530 2" 256 1237 981 3" 66 958 892 1" 481 1290 809 2" 177 870 693 3" 46 588 542 1" 759 1420 661 2" 280 1203 924 3" 72 857 785 1" 609 1440 831 2" 225 1063 839 3" 58 695 637 1" 0 255 255 2" 0 263 263 3" 0 253 253 SE P M 726974 897 1598 830173 429 1290 699926 162 1085 376928 690 1253 538310 330 1067 398225 125 843 120291 1176 1655 141181 562 1070 185311 213 747 323499 619 1257 721970 296 1237 896571 112 1223 280972 805 1398 961566 385 1443 795105 146 1235 654308 557 1488 479860 266 1083 293696 101 810 436815 879 1450 853081 420 1327 615877 159 1057 689893 706 1560 703549 337 1277 406134 128 868 65025 0 295 69344 0 317 63756 0 325 21 E SE 700 490471 861 741587 923 851279 563 317203 737 542853 718 514969 479 229475 508 257949 534 285009 638 406710 941 885138 1110 1233205 593 351522 1059 1120909 1089 1186785 930 865764 817 667602 709 502962 571 326179 907 821853 898 805727 854 730036 939 882470 740 547329 295 87025 317 100278 325 105625 102 Table 26 Continued Age Mix Locations Size P 1" 974 Fume Hood 2" 534 3" 247 1 1" 749 Humidity 2" 411 Chamber 3" 190 1" 1277 Refrigerator 2" 700 3" 324 1" 672 Humidity 2" 369 Chamber 3" 170 1" 874 Fume Hood 2" 479 3" 221 1" 605 Storage Room 2 2" 332 130C 3" 153 1" 954 Room 110A 2" 523 3" 242 1" 766 UDOT 2" 420 3" 194 1" 0 Fog Room 2" 0 3" 0 M 1713 1397 1213 1343 1170 1005 1768 1290 920 1293 1293 1340 1258 1297 1148 1488 1147 888 1480 1413 1207 1695 1460 1020 200 247 247 28 E 738 862 966 594 759 815 491 590 596 621 925 1170 384 817 926 883 815 734 526 890 965 929 1040 826 200 247 247 SE 545314 743624 932257 352915 576046 664268 240846 347654 355559 386095 855095 1368023 147411 668242 857500 779210 664076 538995 276471 791910 930713 862960 1081129 681901 40000 60844 61256 P 1127 775 491 867 596 378 1477 1016 644 777 535 339 1010 695 440 699 481 305 1104 759 481 886 609 386 0 0 0 M 1670 1420 1388 1413 1257 1190 1918 1703 1390 1393 1367 1505 1393 1483 1413 1615 1320 1120 1570 1557 1470 1905 1787 1385 250 287 277 56 E 543 645 896 547 661 812 441 688 746 616 832 1166 382 788 972 916 839 815 466 798 989 1019 1177 999 250 287 277 SE 295386 416189 803434 298980 436407 659650 194413 472880 556836 379687 692396 1359942 146085 621576 944814 838266 703741 664305 217578 636145 977835 1038471 1385952 997459 62500 82178 77006 103 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 67. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Refrigerator at All Ages (Moon and Weiss) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 68. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Fume Hood at All Ages (Moon and Weiss) 104 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 69. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Storage Room 130C at All Ages (Moon and Weiss) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 70. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Room 110A at All Ages (Moon and Weiss) 105 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 71. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in UDOT at All Ages (Moon and Weiss) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 72. Comparison Between Predicted and Measured Shrinkage Values for Mix 2 Samples Stored in Fog Room at All Ages (Moon and Weiss) 106 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 73. Comparison Between Predicted and Measured Shrinkage Values for Mix 1 Samples Stored in Fume Hood at All Ages (Moon and Weiss) 2500 Shrinkage (10-6 in/in) 2000 1" Prisms Prediction 1500 1" Prisms Measured 2" Prisms Prediction 1000 2" Prisms Measured 3" Prisms Prediction 500 3" Prisms Measured 0 0 10 20 30 40 50 60 Time (Days) Figure 74. Comparison Between Predicted and Measured Shrinkage Values for Mix 1 Samples Stored in Humidity Chamber at All Ages (Moon and Weiss) APPENDIX H SEM/EDS SAMPLE PREPARATION The concrete sample preparation steps for the analysis under SEM/EDS were based on the FHWA manual, and are detailed below: Part I: Epoxy Samples were all put into epoxy before flatting and polishing. 1. The appropriate molds were selected based on samples' dimensions; 2. One mold for one sample each time; 3. Acrylic powder and liquid with a liquid/powder ratio of ½ were used as epoxy material; 4. The acrylic liquid was poured into the specific mixing cup firstly, then the powder was added. The mixture was stirred to a "jelly" status, then poured into the mold; 5. A 40-psi pressure was put to the mold by using a pump, then remained for about 10 minutes to a complete solid status to avoid air voids. Part II: Flat and Polishing When samples were all in epoxy, they were flatted and polished to have a better image quality by Gatan 691 Precision Ion Polishing System in University of Utah Nanofab. 1. The RPM number was set to 100 for polishing machine; 108 2. A 60-grade sand paper was used to flat the sample, checked every 5 minutes to see if the tested sample surface is in the same plane with the epoxy surface, which usually takes 1-2 hours. 3. A 180-grade sand paper was used to polish for approximately 30 minutes. Part III: Carbon Coating To avoid changing in SEM, all samples were carbon coated by Gatan 682 Precision Etching Coating System in University of Utah Nanofab Lab after polishing. 1. The Argon gas was turned on for protection; 2. The left and right guns were turned on for approximately 10 minutes for warming up; 3. The chamber and stand were popped out by turning the middle switch to "off" and pushing the "Vent" button; 4. The sample was put on the stand, which was pushed back into the chamber; 5. The "VAC" button was pushed when the Torr number drops; 6. The middle switch was turned to "On"; 7. The rotation wire was turned on; 8. Carbon was selected as the coating material; 9. The left and right guns were turned on; 10. Coating time was set to 20 minutes, then turn on the coating button. The sample was fully carbon-coated when it finished and ready for SEM/EDS analysis. APPENDIX I RAW EDS NUMBER In this section, tables showed the raw data of weight percentage for each of the three randomly selected spots for each chemical element from SEM/EDS and its normalized percentage weight. Table 27 EDS Number for PURETi Sample 09/17/15 Element C O Na Mg Al Si S K Ca Fe Sum Sample 1: PureTi 09/17/15 %Weight (Reading) %Weight (Normalized) Spot 1 Spot 2 Spot 3 Spot 1 Spot 2 Spot 3 Average 16.72 21.14 15.61 16.72 21.58 15.69 18.00 30.44 26.29 30.12 30.44 26.84 30.27 29.18 1.08 0.98 0.95 1.08 1.00 0.95 1.01 1.31 1.60 1.63 1.31 1.63 1.64 1.53 1.75 1.84 1.83 1.75 1.88 1.84 1.82 13.85 9.70 10.70 13.85 9.90 10.75 11.50 1.07 0.93 1.00 1.07 0.95 1.01 1.01 1.66 1.46 2.37 1.66 1.49 2.38 1.84 29.89 31.71 32.43 29.89 32.37 32.59 31.62 2.24 2.30 2.86 2.24 2.35 2.87 2.49 100.01 97.95 99.50 100.00 100.00 100.00 100.00 110 Table 28 EDS Number for TiO2 Sample 09/17/15 Element C O Na Mg Al Si S K Ca Ti Fe Sum Sample 2: 1% TiO2 09/17/15 %Weight (Reading) %Weight (Normalized) Spot 1 Spot 2 Spot 3 Spot 1 Spot 2 Spot 3 Average 9.98 13.03 13.30 9.98 13.03 13.65 12.22 30.42 32.16 31.17 30.42 32.16 31.99 31.53 0.62 0.62 0.62 0.64 0.63 1.49 1.36 2.63 1.49 1.36 2.70 1.85 2.14 1.55 1.83 2.14 1.55 1.88 1.86 10.79 11.72 9.89 10.79 11.72 10.15 10.89 1.18 1.26 1.18 1.26 1.22 0.81 1.79 1.03 0.81 1.79 1.06 1.22 39.44 33.53 33.59 39.44 33.53 34.48 35.82 0.74 0.65 0.77 0.74 0.65 0.79 0.73 3.00 2.33 2.60 3.00 2.33 2.67 2.67 99.99 100.00 97.43 100.00 100.00 100.00 100.00 Table 29 EDS Number for Plain Concrete Sample 09/17/15 Element C O Na Mg Al Si S K Ca Fe Sum Sample 3: Plain Concrete 09/17/15 %Weight (Reading) %Weight (Normalized) Spot 1 Spot 2 Spot 3 Spot 1 Spot 2 Spot 3 Average 15.54 17.15 19.98 15.72 17.33 20.09 17.71 35.70 37.40 30.32 36.11 37.79 30.49 34.80 0.68 1.01 0.69 1.02 0.85 1.51 1.26 1.20 1.53 1.27 1.21 1.34 2.01 2.25 1.96 2.03 2.27 1.97 2.09 10.83 10.03 8.70 10.95 10.14 8.75 9.95 0.64 0.87 1.26 0.65 0.88 1.27 0.93 1.56 1.20 1.06 1.58 1.21 1.07 1.29 28.01 26.32 30.75 28.33 26.60 30.92 28.62 2.38 2.48 3.20 2.41 2.51 3.22 2.71 98.86 98.96 99.44 100.00 100.00 100.00 100.00 111 Table 30 EDS Number for PURETi Sample 10/28/15 Element C O Na Mg Al Si S K Ca Fe Sum Sample 4: PureTi 10/28/15 %Weight (Reading) %Weight (Normalized) Spot 1 Spot 2 Spot 3 Spot 1 Spot 2 Spot 3 Average 12.82 14.85 12.82 14.95 13.89 31.19 40.17 33.24 31.19 40.17 33.47 34.94 0.48 0.48 0.48 1.68 1.00 1.01 1.68 1.00 1.02 1.23 1.85 1.62 1.78 1.85 1.62 1.79 1.75 12.62 25.61 9.80 12.62 25.61 9.87 16.03 1.05 1.01 1.05 1.02 1.03 0.75 1.26 0.95 0.75 1.26 0.96 0.99 35.00 27.95 33.48 35.00 27.95 33.71 32.22 3.03 2.40 2.71 3.03 2.40 2.73 2.72 99.99 100.01 99.31 100.00 100.00 100.00 100.00 Table 31 EDS Number for TiO2 Sample 10/28/15 Element C O Na Mg Al Si S K Ca Ti Fe Sum Sample 5: 1% TiO2 10/28/15 %Weight (Reading) %Weight (Normalized) Spot 1 Spot 2 Spot 3 Spot 1 Spot 2 Spot 3 Average 13.04 12.50 11.74 13.25 12.67 11.84 12.59 28.87 30.86 30.17 29.34 31.28 30.42 30.34 0.56 0.39 0.57 0.40 0.48 1.09 1.43 1.44 1.11 1.45 1.45 1.34 1.90 1.96 2.01 1.93 1.99 2.03 1.98 13.16 14.87 11.84 13.37 15.07 11.94 13.46 0.91 0.99 1.08 0.92 1.00 1.09 1.01 1.29 0.67 0.64 1.31 0.68 0.65 0.88 34.06 31.46 36.20 34.61 31.89 36.50 34.33 0.73 0.83 0.95 0.74 0.84 0.96 0.85 2.79 2.70 3.12 2.84 2.74 3.15 2.91 98.40 98.66 99.19 100.00 100.00 100.00 100.00 112 Table 32 EDS Number for Plain Concrete Sample 10/28/15 Element C O Na Mg Al Si S K Ca Fe Sum Sample 6: Plain Concrete 10/28/15 %Weight (Reading) %Weight (Normalized) Spot 1 Spot 2 Spot 3 Spot 1 Spot 2 Spot 3 Average 11.33 8.89 8.21 11.33 8.91 8.21 9.48 40.57 36.40 35.09 40.57 36.46 35.09 37.37 0.49 0.57 0.49 0.57 0.53 0.39 2.05 1.95 0.39 2.05 1.95 1.46 6.48 2.99 3.07 6.48 3.00 3.07 4.18 24.15 12.87 12.07 24.15 12.89 12.07 16.37 0.58 0.60 0.58 0.60 0.59 1.72 0.94 0.91 1.72 0.94 0.91 1.19 13.61 30.92 33.22 13.61 30.97 33.22 25.93 1.76 3.70 4.32 1.76 3.71 4.32 3.26 100.01 99.83 100.01 100.00 100.00 100.00 100.00 APPENDIX J RAW TGA 114 400 0.07 350 0.06 300 0.05 0.04 250 0.03 200 0.02 150 0.01 Ion Current (A) DTA signal (%mass/ºC) a) 0.08 DTA signal CO2 H2O 100 0.00 10 20 -0.02 30 40 50 Time (min) 60 50 0 b)100% 0.08 98% 0.07 TGA (%mass) 0.06 TGA (%mass) 96% 0.05 94% 0.04 92% 0.03 90% 0.02 0.01 88% DTA Signal (%mass/ºC) 0 86% -0.01 84% -0.02 1000 0 200 400 600 Temperature (ºC) 800 Figure 75. Plain Concrete 08/12/15 at 5 mm Depth a) MS; b) TGA DTA Signal (%mass/ºC) 0 -0.01 0.06 140 0.05 120 0.04 100 0.03 80 0.02 60 0.01 40 0.00 20 0 10 20 -0.01 b) 30 40 50 Time (min) DTA signal CO2 H2O 60 0 0.06 100% 0.05 98% TGA (%mass) TGA (%mass) 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 76. Plain Concrete 08/12/15 at 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 115 116 a) 0.06 120 0.05 0.04 0.03 80 0.02 60 0.01 40 0.00 -0.01 0 10 20 30 40 50 Ion Current (A) DTA signal (%mass/ºC) 100 DTA signal CO2 H2O 60 20 -0.02 -0.03 0 0.06 100% TGA (%mass) 0.05 98% TGA (%mass) 0.04 96% 0.03 94% 0.02 92% 0.01 DTA Signal (%mass/ºC) 0 90% -0.01 88% -0.02 86% 0 200 400 600 Temperature (ºC) 800 -0.03 1000 Figure 77. Plain Concrete 08/12/15 at 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) Time (min) 117 a) 2.50 0.06 2.00 0.04 1.50 0.03 0.02 1.00 Ion Current (A) DTA signal (%mass/ºC) 0.05 DTA signal CO2 H2O 0.01 0.50 0.00 0 10 20 -0.01 40 50 Time (min) 60 0.00 100% 0.06 TGA (%mass) 98% 0.05 TGA (%mass) 96% 0.04 94% 0.03 92% 0.02 90% 0.01 88% DTA Signal (%mass/ºC) 86% 0 84% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 78. Plain Concrete 09/17/15 at 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) 30 118 a) 2.50E-09 0.07 2.00E-09 0.05 0.04 1.50E-09 0.03 1.00E-09 0.02 Ion Current (A) DTA signal (%mass/ºC) 0.06 DTA signal CO2 H2O 0.01 5.00E-10 0.00 0 -0.01 20 30 40 Time (min) 50 60 0.00E+00 0.07 100% TGA (%mass) 0.06 TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 79. Plain Concrete 09/17/15 at 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) 10 0.08 5.00 0.07 4.50 0.06 4.00 3.50 0.05 3.00 0.04 2.50 0.03 2.00 0.02 1.50 0.01 b) CO2 H2O 1.00 0.00 -0.01 DTA signal 0.50 0 10 20 30 40 50 Time (min) 60 0.00 100% 0.08 TGA (%mass) 0.07 98% TGA (%mass) 0.06 96% 0.05 0.04 94% 0.03 92% 0.02 0.01 90% DTA Signal (%mass/ºC) 0 88% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 80. Plain Concrete 10/28/15 at 5 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 119 120 0.06 160 0.05 140 120 0.04 100 0.03 80 0.02 60 0.01 DTA signal CO2 H2O 40 0.00 0 10 20 -0.01 b) Ion Current (A) DTA signal (%mass/ºC) a) 30 40 50 Time (min) 60 20 0 100% 0.06 TGA (%mass) TGA (%mass) 0.04 96% 0.03 94% 0.02 92% 0.01 90% 0 DTA Signal (%mass/ºC) 88% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 81. Plain Concrete 10/28/15 at 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) 0.05 98% 121 800 0.05 700 600 0.03 500 400 0.02 300 0.01 0 10 20 -0.01 TGA (%mass) CO2 H2O 200 0.00 b) DTA signal 30 40 50 Time (min) 60 100 0 100% 0.05 TGA (%mass) 98% 0.04 96% 0.03 94% 0.02 92% 0.01 DTA Signal (%mass/ºC) 90% 0 88% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 82. Plain Concrete 10/28/15 at 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) 0.04 Ion Current (A) a) 122 a) 0.08 300 0.07 0.06 0.05 200 0.04 150 0.03 100 0.02 Ion Current (A) DTA signal (%mass/ºC) 250 DTA signal CO2 H2O 0.01 50 0.00 TGA (%mass) b) 0 10 20 30 40 50 Time (min) 60 0 100% 0.08 TGA (%mass) 98% 0.07 96% 0.06 0.05 94% 0.04 DTA Signal (%mass/ºC) 92% 0.03 90% 0.02 88% 0.01 86% 0 84% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 83. PureTi 08/12/15 at 5 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) -0.01 123 a) 250 0.06 200 0.04 150 0.03 0.02 100 Ion Current (A) DTA signal (%mass/ºC) 0.05 DTA signal CO2 H2O 0.01 50 0.00 0 10 20 -0.01 b) 30 40 50 Time (min) 60 0 0.06 100% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 84. PureTi 08/12/15 at 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) TGA (%mass) TGA (%mass) 98% 124 0.06 400 0.05 350 300 0.04 250 0.03 200 0.02 150 0.01 DTA signal CO2 H2O 100 0.00 0 10 20 -0.01 30 40 50 Time (min) 60 50 0 100% 0.06 TGA (%mass) 98% 0.05 TGA (%mass) 96% 0.04 94% 0.03 92% 0.02 90% 0.01 88% DTA Signal (%mass/ºC) 86% 0 84% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 85. PureTi 08/12/15 at 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) Ion Current (A) DTA signal (%mass/ºC) a) 125 a) 500 0.10 450 400 350 0.06 300 250 0.04 200 0.02 150 DTA signal CO2 H2O 100 0.00 0 10 20 -0.02 30 40 50 Time (min) 60 50 0 100% 0.1 TGA (%mass) 98% 0.08 TGA (%mass) 96% 0.06 94% 92% 0.04 90% 0.02 88% 0 DTA Signal (%mass/ºC) 86% 84% 0 200 400 600 Temperature (ºC) 800 -0.02 1000 Figure 86. PureTi 09/17/15 at 5 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) Ion Current (A) DTA signal (%mass/ºC) 0.08 126 0.06 160 0.05 140 120 0.04 100 0.03 80 0.02 60 0.01 0 10 20 -0.01 CO2 H2O 30 40 50 Time (min) 60 20 0 0.06 100% TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 87. PureTi 09/17/15 at 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) TGA (%mass) DTA signal 40 0.00 b) Ion Current (A) DTA signal (%mass/ºC) a) 0.06 350 0.05 300 0.04 250 0.03 200 0.02 150 0.01 100 0.00 50 0 10 20 -0.01 TGA (%mass) b) 30 40 50 Time (min) DTA signal CO2 H2O 60 0 0.06 100% TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 88. PureTi 09/17/15 at 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 127 128 0.12 800 0.10 700 600 0.08 500 0.06 400 0.04 300 0.02 DTA signal CO2 H2O 200 0.00 0 10 20 -0.02 30 40 50 Time (min) 100% 60 100 0 0.12 TGA (%mass) 98% 0.1 TGA (%mass) 96% 0.08 94% 0.06 92% 90% 0.04 DTA Signal (%mass/ºC) 88% 0.02 86% 0 84% 82% 0 200 400 600 Temperature (ºC) 800 -0.02 1000 Figure 89. PureTi 10/28/15 at 5 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) Ion Current (A) DTA signal (%mass/ºC) a) 0.06 300 0.05 250 0.04 200 0.03 150 0.02 100 0.01 0 10 20 -0.01 TGA (%mass) CO2 H2O 50 0.00 b) DTA signal 30 40 50 Time (min) 60 0 0.06 100% TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 0.01 90% DTA Signal (%mass/ºC) 88% 0 86% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 90. PureTi 10/28/15 at 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 129 0.06 350 0.05 300 0.04 250 0.03 200 0.02 150 0.01 100 0.00 50 0 10 20 -0.01 TGA (%mass) b) 30 40 50 Time (min) DTA signal CO2 H2O 60 0 0.06 100% TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 91. PureTi 10/28/15 at 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 130 131 350 0.09 DTA signal (%mass/ºC) 0.08 300 0.07 250 0.06 0.05 200 0.04 150 0.03 0.02 Ion Current (A) a) DTA signal CO2 H2O 100 0.01 50 0.00 b) 0 10 20 30 40 Time (min) 50 60 0 100% 0.09 TGA (%mass) 0.08 98% 0.07 TGA (%mass) 96% 0.06 94% 0.05 92% 0.04 DTA Signal (%mass/ºC) 90% 0.03 0.02 88% 0.01 86% 0 84% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 92. TiO2 09/17/15 5 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) -0.01 132 90 0.06 80 70 0.04 60 0.03 50 0.02 40 30 0.01 0 10 20 -0.01 TGA (%mass) CO2 H2O 20 0.00 b) DTA signal 30 40 50 Time (min) 60 10 0 0.06 100% TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 93. TiO2 09/17/15 10 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) 0.05 Ion Current (A) a) 0.06 300 0.05 250 0.04 200 0.03 150 0.02 100 0.01 0 10 20 -0.01 TGA (%mass) CO2 H2O 50 0.00 b) DTA signal 30 40 50 Time (min) 100% 60 0 0.06 TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% 0 200 400 600 Temperature (ºC) 800 -0.01 1000 Figure 94. TiO2 09/17/15 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 133 134 500 0.12 450 DTA signal (%mass/ºC) 0.10 400 0.08 350 300 0.06 250 0.04 200 150 0.02 Ion Current (A) a) DTA signal CO2 H2O 100 0.00 0 10 20 -0.02 40 50 Time (min) 60 50 0 100% 0.12 TGA (%mass) 98% 0.1 TGA (%mass) 96% 94% 0.08 92% 0.06 90% 0.04 88% DTA Signal (%mass/ºC) 86% 0.02 84% 0 82% 80% 0 200 400 600 Temperature (ºC) 800 -0.02 1000 Figure 95. TiO2 10/28/15 5 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) b) 30 0.07 350 0.06 300 0.05 250 0.04 200 0.03 150 0.02 CO2 H2O 100 0.01 50 0.00 0 10 20 -0.01 30 40 50 Time (min) b) 100% TGA (%mass) DTA signal 60 0 0.07 TGA (%mass) 98% 0.06 96% 0.05 94% 0.04 92% 0.03 90% 0.02 88% 0.01 DTA Signal (%mass/ºC) 86% 0 84% 0 200 400 600 Temperature (ºC) 800 Figure 96. TiO2 10/28/15 10 mm Depth a) DTA-MS; b) TGA -0.01 1000 DTA Signal (%mass/ºC) DTA signal (%mass/ºC) a) Ion Current (A) 135 136 180 0.06 160 140 0.04 120 0.03 100 0.02 80 60 0.01 0 10 20 -0.01 TGA (%mass) CO2 H2O 40 0.00 b) DTA signal 30 40 50 Time (min) 60 20 0 0.06 100% TGA (%mass) 98% 0.05 96% 0.04 94% 0.03 92% 0.02 90% 0.01 DTA Signal (%mass/ºC) 88% 0 86% -0.01 1000 0 200 400 600 Temperature (ºC) 800 Figure 97. TiO2 10/28/15 15 mm Depth a) DTA-MS; b) TGA DTA Signal (%mass/ºC) DTA signal (%mass/ºC) 0.05 Ion Current (A) a) REFERENCES A. Fujishima, K. H., and Kikuchi, S. (1969). 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