Characterization of the coefficient of thermal expansion and its effect on the performance of Portland cement concrete pavements

The coefficient of thermal expansion (CTE) of concrete is considered to be an important design parameter to predict Portland cement concrete (PCC) pavement performance in mechanistic-empirical pavement design guide (MEPDG). This study measured CTE values of concrete specimens having various coarse aggregates, and investigated the relationship between the CTE and critical design parameters. It was found that aggregate types, the amount of coarse aggregate, and relative humidity (RH) had a statistically significant impact on the CTE. Expansion CTE had a higher variation compared to contraction CTE, and the maximum value of expansion CTE at 63% RH was 8% higher than the value at 100% RH. Sensitivity analysis showed that inaccurate estimation of concrete CTE can cause serious error in predicting the performance of PCC pavements. A prediction equation of concrete CTE was introduced by modifying Hansen's model and the predicted CTE value had a good agreement with the measured CTE.