| In this study, the performance under reversed cyclic loading of beam-column joint subassemblages made with relatively new materials is investigated and compared to that of conventional steel-reinforced code conforming joints. For instance, the performance of a steel-free GFRP (glass fibre reinforced polymers)-reinforced beam-column joint subassemblage was examined. This type of construction can be employed where high resistance to corrosion is needed or when magnetic neutrality is required. However, due to the inherent elastic behaviour of fibre reinforced polymers (FRP), the steel free subassemblage exhibited low energy dissipation and ductility. Thus, a full-scale hybrid steel-GFRP reinforced beam-column joint subassemblage was investigated. This reinforcement configuration was able to dissipate energy and produce a ductile failure. A large concrete cover protects the steel reinforcement, while the outer reinforcement, which has a typical concrete cover, consists only of GFRP. The study also looked into the use of self-consolidating concrete (SCC) in order to enhance the construction of beam-column joint subassemblages by eliminating the need for mechanical vibration and achieving higher quality finish surfaces. Despite the fact that the beam-column joint subassemblage made using SCC was able to reach a similar load-carrying capacity to that of a normal concrete joint, it could not maintain such capacity at high deformations due to the relatively low aggregate content in SCC and the reduced contribution of aggregate interlock to shear-resisting mechanisms.; The study also proposed a new shear stress-strain function to model the behaviour of reinforced concrete structures under monotonic and cyclic loading. In contrast to many available shear models for reinforced concrete, which rely on empirical formulations, the proposed shear stress function uses a rational approach along with simplified yet accurate cyclic rules. A simple yet accurate normal stress function describing the cyclic behaviour of reinforced concrete under axial stress is also employed. The proposed functions were verified using experimental data of reinforced concrete panels tested under monotonic and cyclic loading. Subsequently, the normal and shear stress functions along with their cyclic rules are integrated in a nonlinear finite element analysis code and used to analyse two shear walls and different beam-column joint specimens under cyclic loading. The model showed an excellent capacity for predicting shear deformations of reinforced concrete elements under cyclic loading with minimal computational efforts. (Abstract shortened by UMI.)... |
