A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1991

The subject of this study is to enhance the applicability of contact density model to reinforced concrete, and to propose a generalized stress transfer model, which can predict behaviors across any concrete crack plane, subjected to cyclic loading. The reversed cyclic stress transfer mechanism of concrete across a crack in reinforced concrete flexural members has been investigated in this study. Experimental reversed cyclic shear load - shear displacement and moment - curvature results for concrete only in reinforced concrete members are given. In reinforced concrete flexural members, the crack surface, geometry of the crack and its mechanical behaviors are experimentally found to be quite different from those of normal plain concrete, and the microcracking, nonlinear interaction between bars and flexural bending reduce the ultimate shear carrying capacity of rough crack. A single crack in reinforced concrete flexural member is discretized into finite numbers of elements. Within these elements the rough crack surface is idealized as a set of numerous contact units with various inclinations. The distribution of their direction is expressed by the "Modified Contact Density Function". In each direction the contact units can transfer the normal stress and shear stress, which are formulated by elasto-plastic model. The derived model is capable of dealing not only with monotonic loading but also with cyclic loading and verified by a series of experimental results.