Moisture Gradient and Time-Dependent Crack Growth in Restrained Concrete Elements Subjected to Drying

Recent research has shown that the risk of early-age shrinkage cracking in concrete is influenced by many factors including the rate of shrinkage, the rate of strength development, the degree of restraint, and the extent of stress relaxation (creep). Previous research introduced an analytical model to predict residual stress development in restrained concrete elements, however this model assumed that the concrete was undamaged (i.e., uncracked) at each age before determining if the increase in shrinkage was significant enough to cause failure. This paper presents an approach to account for the role of moisture gradients on residual stress development that considers stable crack growth in restrained specimens over time. The model can be used to illustrate how alterations in binder composition (i.e., changes in ultimate shrinkage and autogenous/drying effects) change the residual stresses that develop and the resulting potential for cracking.