Modeling on Shrinkage Stress in Early-Age Concrete Pavements

Abstract

In this paper, an integrative model for autogenous and drying shrinkage predictions of concrete at early-age is introduced first. Second, a model taking both cement hydration and moisture diffusion into account synchronously is used to calculate the distribution of interior humidity in concrete. Using the two models, the distribution of shrinkage strain in early-age concrete pavements under the condition that the pavement surface suffers to dry is calculated. Afterwards, the shrinkage stress resulted from the nonlinear shrinkage strain is calculated by dividing the shrinkage strain into uniform strain, linear strain and nonlinear strain. The model results show that the gradient of shrinkage strain and stress along the slab depth is obvious under the condition that the slab top suffers to dry. The maximum and minimum shrinkage strain and stress occurs at slab top and bottom respectively. The distribution of shrinkage strain and stress along the pavement depth are nonlinear and the nonlinearity is strong close to the drying face and the rest is weak.