EXPERIMENTAL STUDY ON MECHANICAL BEHAVIOR OF SLAB CONNECTIONS UNDER COMBINED SHEAR AND TENSION LOADING

An experimental program consisting the prototype tests of selected twelve slab connections was conducted to evaluate the mechanical behavior of the proposed slab connections used in discrete connected precast RC diaphragms (DCNPD) under combined shear with tension loading. The performance of test specimens was evaluated in terms of shear bearing capacity, crack and failure mode, ductility, strain response, etc. The test results indicated that:1) due to the presence of tension, the compressive force resulting from the shear demand was reduced to a certain decreased magnitude, and as the tension to shear force ratio increased, the shear bearing capacity decrease the effect of slab connection become more evident; 2) due to the presence of tension, the progress into nonlinear stage of the slab connection was accelerated; 3) and also, the shear deformation ductility of slab connection decreased due to the existing of tension, especially for the connections in high tension to shear force ratio area, and proper measures should be adopted to avoid brittle failure. According to the performance of slabs in force-deformation responses, in ductility, and in failure model, the three connections named HPC, CPC and HP-CPC are ideal slab joints for DCNPD, but welds between the anchor bar and anchor plate of SPC connections are inclined to fracture under combined loading, and proper measures should be used to improve its property.