Modeling hydration properties and temperature developments of early-age concrete pavement using calorimetry tests

This research aims to evaluate the calorimetry tests for characterizing cement hydration properties and predicting temperature developments of the early-age Portland cement concrete pavement (PCCP). Analytical models are studied to simulate hydration properties, using the measured heat evolution data from both the isothermal and semi-adiabatic tests. HIPERPAV III (R) engineering software with these analytical models embedded is used to predict temperature developments of the early-age PCCP. Results show that the maximum hydration time parameter tau corresponds to the maximum activation energy E-a. Semi-adiabatic tests result in a lower hydration shape parameter beta yet a higher hydration time parameter tau than isothermal tests. As results, the simulated degree of hydration based on semi-adiabatic tests is higher at the early hours, but lower at later hours compared to that based on isothermal tests. This effect is also reflected from the simulated temperature developments of the early-age PCCP. Three engineering projects in this research show that predicted temperatures of the PCCP using hydration parameters determined from semi-adiabatic tests better match actual measurements than that from isothermal tests. (C) 2010 Elsevier B.V. All rights reserved.