Experimental study of temperature rise of concrete and assessment of cracking due to internal restraint

Experimental study was carried out on a prototype structure to investigate the temperature rise characteristics of the concrete used. Two thermocouples each in 2 layers at four similar locations, totaling 16 numbers were embedded during the concreting of said structure to assess the characteristics of the temperature rise and temperature difference at peak in the concrete. The cement used was OPC in first layer and was replaced by PPC in other layer to find out the effect on the temperature rise and the temperature difference at peak. The study revealed that the temperature rise in concrete with PPC was much less than where OPC was used. The derived temperature rise equations with strong R² values could be used to predict the early age temperature rise in structures with similar geometry, weather conditions, curing and form removal.

Another purpose of this study is to know the probability of cracking based on the existing cracking assessment based on Korean methods as Indian specifications are non-existent and also to find the crack index for internally restraint cases both the elastic; hypoelastic models. The study indicated that the existing provisions based on crack index appear to be very conservative which tend to overestimate the probability of crack occurrence compared with construction observations on prototype structures.