Early age thermal crack control in mass concrete

Abstract

Early age thermal cracking due to temperature differential is one of the major issues related to mass concrete construction. Temperature differential is created due to heat of hydration of cement and heat loss from the surface. If induced tensile stresses due to temperature differential exceed tensile strength of concrete, concrete tends to crack. Current practice in the local construction industry is to limit the temperature differential to 20ºC irrespective of the grade of concrete. A Finite Element Model (FEM) was developed using ANSYS to predict early age thermal stress behavior. Appropriate position of thermocouples to measure the temperature differential in mass concrete was also proposed based on a thermal analysis using FEM. Limiting values for the temperature differential were proposed based on analytical methods to minimize the risk of thermal cracking.