Numerical simulation of risk mitigation methods for early age thermal cracking of concrete

Minimising the risk of early age thermal cracking is a major challenge faced by the concrete industry when dealing with mass concrete, large restrained concrete elements, and concrete with high cement content. With this in mind, several numerical simulation models and guidelines have been developed to predict the temperature rise in concrete and to provide guidelines on design of reinforcements to limit the width of resulting cracks. However, such models have a number of key limitations which include inability to consider the effect of admixtures, providing 2D rather than 3D representation of the element, and inability to investigate different risk minimisation scenarios including placement of concrete in multiple layers, mix optimisation and embedment of cooling pipes. Among these, the latter is of particular importance as it considerably limits the ability of concrete specialists in dealing with high risk scenarios. In this paper, the working principles and features of a novel multi-physics numerical simulation model developed to address the above limitations is presented. The proposed model is then applied to three different real-life case studies to demonstrate its application in evaluating the effectiveness of sequential concrete placement and internal cooling strategies on minimising the risk of early age thermal cracking in the presented case studies.