Research Methods of Reinforcement with Concrete Interaction Part 1. Experimental and Analytical Methods
Reinforced concrete is a composite material that consists of reinforcement and concrete. The strain compatibility of reinforced concrete is ensured by the resistance of concrete to displacement of reinforcement, which is determined by the properties of reinforcement and concrete. This paper is devoted to methods for study this property of reinforced concrete. In the first part, experimental and analytical research methods are considered. Experimental research methods differ in test schemes, specimen design and the type of information characterizing the reinforcement with concrete interaction. Two tests of bond for reinforcement steel prevail -pull-out test and beam test. In these cases, the displacements of concrete and reinforcement and their deformations are measured separately or a combination of these measurements is made. This information allows formulating mathematical models of reinforced concrete deformation. Analytical theories of bond are considered, which simplify the real process of reinforcement with concrete interaction. These theories only describe the resistance of concrete to axial displacement of the reinforcement. The main provisions of such analytical theories were formulated in the technical theory of bond by M. М. Kholmyanskiy. This theory considers the interaction of three components: concrete, bond-slip layer and reinforcement. The main element of the model is the bond-slip layer, the characteristics of which relate the displacements and forces of contact interaction between reinforcement and concrete. The analysis of experimental and analytical methods made it possible to select the type test of bond for reinforcement steel with concrete for solving specific problems.