Prediction of Pavement Concrete Strength Development, Joint Sawing, and Opening Time Using FEMLAB

Abstract

This paper describes a new model using Finite Element Modeling Laboratory (FEMLAB). The model can be used to predict pavement strength development and consequently the pavement joint-sawing and opening times. The strength prediction was based on the temperature history of the concrete pavement, which was determined by the rate of heat generation and the heat exchange between the pavement and the environment. Pavement joint-sawing and opening times were defined as the times when concrete strength reached 4.3 and 24.1 MPa (megapascals), respectively. Using this model, the effects of weather conditions, fly ash and slag replacement, concrete placement time and temperature, and pavement thickness on concrete strength, joint-sawing time, and pavement opening time were evaluated. Results showed that weather conditions and the use of fly ash and slag had a significant effect on strength development, joint-sawing time, and pavement opening time. Based on the prediction, this model can be used to optimize the concrete mix design to select the appropriate concrete placement temperature and paving time for the optimal concrete construction and strength development under certain environmental condition.