A generic unified reinforced concrete model

Abstract

The behaviour of reinforced concrete members with ductile steel reinforcing bars at the ultimate limit state is extremely complex. Consequently, there has been a tendency for the seemingly disparate research areas of flexure, shear and confinement to follow separate paths in order to develop safe approaches to design. In this paper, it is shown how the already much researched and established, but somewhat peripheral, areas of reinforced concrete research of shear friction, partial interaction and rigid body displacements can be combined to produce a single unified reinforced concrete model that simulates the moment–rotation of hinges and their capacities, the shear deformation across critical diagonal cracks leading to failure and the effect of confinement on these behaviours. It is shown that this unified reinforced concrete model is completely generic, as it can be used to simulate reinforced concrete members with any type of reinforcement material (including brittle steel or fibre-reinforced polymer), various cross-sectional shapes of reinforcement (not only round bars but also flat externally bonded or rectangular near surface mounted adhesively bonded plates) and any type of concrete (e.g. high-strength or fibre-reinforced concrete). This new model, therefore, should allow the development of more accurate and safe design procedures as well as enabling more rapid development of new technologies.