Preliminary notions for prediction of cracking in expansive concrete based on its crack resistant mechanism

摘要

This paper presents some preliminary ideas for predicting cracking of expansive concrete. For normal concrete, which shows almost linear behavior before cracking, the stress-based criterion for predicting cracking is reasonable. However, a well-confined expansive concrete shows highly nonlinear behavior and large deformability, up to cracking in tension. This is assumed to be due to the internal microscopic strains being widely distributed and varied. This peculiar strain distribution is caused by the combination of simultaneous processes, namely solidification due to hydration and volumetric deformation due to the generation of expansive energy. To accurately predict cracking, the stress-based criterion has little sense for expansive concrete, especially in flexure. Thus, some preliminary ideas for more appropriate approach are discussed based on mechanism of expansive concrete.