Modeling the crack-resistance of high-strength self-compacting concrete

Abstract

The results of modeling the crack resistance of high-strength self-compacting concretes are presented. By modeling elastic and microplastic deformations from the deformation diagrams of prism specimens with an initiated crack, the parameters of crack opening in the concretes under study were established. According to the model, it was found that the width of the opening of shrinkage cracks in all investigated concretes (by 120 days) significantly exceeds this indicator for the beginning of the formation of the main crack. Thus, with limited shrinkage, the formation of cracks in the concretes is inevitable. In accordance with the model, the formation of shrinkage microcracks of concrete without additives begins on the 9th day, and the formation of the main crack — onthe 11th day of hardening. The beginning of the formation of shrinkage microcracks in concrete with fly ash, limestone and microsilica begins on the 6th day of hardening. The formation of shrinkage main cracks in these concretes begins on the 8th, 10th and 11th days of hardening, respectively. The beginning of the formation of shrinkage microcracks in concrete with metakaolin begins on the 8th day, and the main crack — on the 17th day of hardening. Thus, the composition of concrete with metakaolin can be considered the most crack-resistant. This is due to less shrinkage, a relatively low modulus of elasticity and a relatively large area ofmicroplastic deformation of concrete with metakaolin