Experimental study on seismic behaviour of an unreinforced precast wall-slab structure based on UHPC sandwich panels

Heavy prefabricated components and complex reinforcement arrangements are regarded as main problems affecting the construction efficiency of traditional precast concrete structures. This study proposes a new wall-slab structure based on prefabricated ultra-high performance concrete (UHPC) sandwich panels, which features with light weight, no reinforcement, fast bolt-based dry connection and insulation system integrated. A large-scale two-story substructure is prefabricated and assembled, which consists of eight sandwich walls and four sandwich slabs. Vertical load test and lateral cyclic load test are conducted to investigate the mechanical behavior of the wall-slab structure. The cracking patterns, failure modes, bearing capacity, stiffness, energy dissipation capacity, and strain distribution are analyzed. Test results demonstrate that the maximum and cracking base shear forces are about 10 and 7 times the sum of gravity and live load of the specimen, respectively. The various connections between precast panels are all reliable without obvious damage during the test. Therefore, the new wall-slab structure has excellent seismic performance, which can even avoid cracking under severe earthquake. In addition, design suggestions are proposed based on the test results, regarding the design principle, inter-story drift ratio limit and panel connections.