The performance of a precast concrete building during an earthquake depends on the behaviour of the joints between the precast members. The present study investigates the in-plane shear behaviour of wall-to-wall vertical joints. Conventionally, a vertical joint is achieved by overlapping the transverse joint reinforcement (in the form of steel U-bars or looped wire ropes) from the wall panels, and in-situ grouting of the gap between the panels. However, from previous studies, the behaviour of such grouted vertical joints was found to be brittle.
The present study aimed to improve the behaviour of grouted vertical joints in terms of ductility. To achieve this objective, joints with diagonal reinforcement were experimentally investigated. This seminar presents the brief of monotonic test results and the behaviour of specimens tested under cyclic loading. Based on the monotonic test results, a model for the joint behaviour is proposed and its use in the numerical simulation of a standalone wall assemblage is presented. Another numerical simulation of the tested specimens using commercially available FEM software is also presented.
From the test results, it is found that the specimens with diagonal connectors show better performance compared to specimens with overlapping U-bars or looped wire ropes. After incorporating the proposed model for the joint behaviour into the simulation of the wall assemblage, the strength and deformability of the assemblage improve.