Experimental and Theoretical Studies of the Concrete Static-Dynamic Stress–Strain Curves

Abstract

During operation, both of a residual static and dynamic load can be applied to the structural members, and in the case of an emergency impact, such as the sudden structural member removal, the dynamic additional loading arises in the structural elements. Ultimate deformations and strength of concrete and reinforced concrete under this loading mode significantly differ from their values under static or dynamic loading mode. This paper presents the results of experimental and theoretical determination of the concrete stress–strain curve parameters for varying levels of the initial static load and loading modes. The differential equation of the concrete deformation model for the static-dynamic loading mode and its solution at various levels of the initial static stress were obtained. It was established that the maximum permissible time of impact on a concrete specimen under dynamic additional loading and the ultimate strength of concrete depend on the level of the initial static load. Numerical analysis and specimens’ tests shown that parameters of the concrete stress–strain curves under static-dynamic loading mode substantially depend on the level of initial relative stresses in concrete.