Nonequilibrium processes of power and enviromental resistance of reinforced concrete structures to progressive collapse

Abstract

The problems of calculating the parameters of non-equilibrium power and environmental resistance of reinforced concrete elements of a structural system under special effects are considered. A static-dynamic diagram of the deformation of corrosion-damaged concrete during overlimit impact caused by the sudden removal of a supporting structure is constructed. The section of this diagram is described by the analytical dependence for change in the strength of loaded and corrosion-damaged concrete from time, which takes into account, on the one hand, the process of the increasing strength of “healthy” concrete in time (theory of concrete aging), and on the other, the process of the degradation of an aggressive environment on concrete. A section of the dynamic deformation diagram is described by the Kelvin-Voigt model in a version of the theory of plasticity of concrete G.A. Genius, which corresponds to the conditions of deformation of concrete as an elastic-viscous-plastic material. The dynamic tensile strength of corrosion-damaged concrete is taken into account by the coefficient of increase in the dynamic strength of the material based on the two-element model of its deformation.