Coefficient of thermal expansion of Portland cement concrete in Utah and pavement performance

A laboratory investigation was conducted to determine the coefficient of thermal expansion (CTE) of typical Utah Department of Transportation (UDOT) concrete pavement mixtures made with aggregate obtained from 18 different sources around the state of Utah. The predominant aggregate type used in the concrete mixtures included quartzite, limestone, and basalt. The CTE of the concrete samples was determined using the AASHTO standard T336-09 Coefficient of Thermal Expansion of Hydraulic Cement Concrete. Three replicate test specimens were fabricated for each different aggregate source. All concrete specimens met the requirements for UDOT (AA)AE-type mixture. All specimens were moist-cured in a lime-bath for a minimum of 28 days after which their compressive strength and CTE were measured. CTE testing was not conducted on any specimens until they fulfilled the requirements set by the AASHTO standard T336- 09. The average CTE values for concrete containing quartzite aggregate is 5.63 |ie/0F and ranging from 4.34 [xc/°F to 6.21 JIE/°F. The average CTE result for concrete containing limestone aggregate is 4.67 |XE/°F and ranging from 4.26 jj,e/°F to 5.25 U£/°F. The average CTE result for concrete containing basalt aggregate is 4.46 U£/°F and ranging from 4.17 |i£/°F to 4.74 |as/°F. Test results conclude that aggregate geology has a significant effect on CTE results. In addition, this work also discusses the actual impact of the CTE changes on the performance of jointed plain concrete pavements as measured by transverse cracking, faulting, and international roughness index (IRI).