Early-age concrete stresses induced by drying shrinkage and thermal dilation

To fully understand the role of drying shrinkage and thermal stresses in concrete crack development, the material-induced stress distribution must be investigated. A simple model is presented for quantifying the internal stress distribution in concrete exposed to drying, temperature changes, or self-desiccation. The measured concrete internal relative humidity, which has a fundamental relationship to material-induced stress development, is a main parameter in the model. The free shrinkage stress distribution and fully restrained stress distribution is modeled for a broad range of concrete mixtures. The model predicts a growing zone of damage near the drying surface of the fully restrained concrete which may be related to crack initiation. Further development of this model and combination with fracture and finite element models may lead to an improved understanding of concrete cracking in real structures and pavements.