Evaluating Hydration Characteristics and HIPERPAV Prediction of Temperature Development in Early-Age Concrete Pavement

Cement hydration plays a key role in developments of temperatures and associated critical stresses and distresses of early-aged concrete pavement. Degree of hydration has been characterized by hydration parameters (i.e. activation energy and hydration curve parameters), which are affected by a myriad of factors including material components and test methods. Thus, it is essential to evaluate the influences of these factors on hydration parameters in order to better characterize hydration properties and capture temperature development. Accordingly, this paper aims to ascertain hydration characteristics for predicting temperature development. Isothermal and semi-adiabatic tests were performed on cement mortar and concrete containing water reducing admixtures and fly ash to determine hydration parameters. Federal Highway Administration (FHWA) HIPERPAV software was used to predict temperature developments. Test results show that activation energy and hydration curve parameters are affected by water reducing admixtures, fly ash, and test methods. The simulated pavement temperatures using HIPERPAV software show reasonable agreements with field measurements. A higher accuracy could be achieved in HIPERPAV analysis by using hydration curve parameters calculated from semi-adiabatic test data than that from isothermal test data. As part of the research results, the HIPERPAV software was modified to provide a user-friendly Window to define hydration parameters for enhancement of temperature prediction.