Effect of Internal Water Pressure on the Measured Coefficient of Thermal Expansion of Concrete

Abstract

A study was conducted to evaluate the effect of coefficient of thermal expansion (CTE) test procedures and length-change measuring devices on the measured CTE values. Twenty different coarse aggregate sources were tested using the Texas Department of Transportation (TxDOT) and the American Association of State Highway and Transportation Officials (AASHTO) suggested CTE methods. Two different types of length-change measuring devices, linear variable differential transformers (LVDTs) and differential variable reluctance transducers (DVRTs), were used. No significant effects of length-change measuring devices were observed on the CTE values measured by the TxDOT method. However, the test methods have shown effects on the measured values. The TxDOT method yields higher CTE values than the AASHTO method. Data obtained in this study confirmed that the internal water pressure development during the heating and cooling cycles is one of the potential reasons. Internal water pressure can significantly affect the CTE of concrete. Further investigation is needed to determine the effect of internal water pressure on the CTE, which affects the design and service life of concrete pavements.