Seismic performance of pre-cast self-insulation shear walls made by a new type of foam concrete with high strength and low thermal conductivity

Abstract

Foam concrete with high strength and low thermal conductivity (HLFC) was developed by using certain mix ratio and physical mixing method, which could be used as load-bearing structure material. The mechanical properties and thermal conductivity of HLFC were obtained through a series of tests. Combining the concept of energy-saving and industrialization of building, a new type of assembled self-insulation shear wall prefabricated by HLFC and suitable for low-rise residential buildings was proposed. In order to study the seismic performance of the wall, three specimens considering different axial compression ratio and height-width ratio were designed, and the failure mode, seismic bearing capacity, ductility, stiffness degradation and energy dissipation capacity of them were analyzed under in-plane cyclic load. Test results showed that HLFC with density of A-08 grade had higher compressive strength and lower thermal conductivity than the traditional foam concrete. The new type of assembly connection effectively maintained the structural integrity and had stable hysteretic performance under cyclic load. But, the diagonal cracks generated were much more than ordinary concrete shear walls because of the relatively low strength. The increase of axial compression ratio from 0.1 to 0.2 changed the controlling failure mode of the wall with bending-shear failure mode, and brought an obvious increase in the load-bearing capacity by nearly 2 times. With the decrease of height-width ratio from 1.56 to 0.93, the HLFC shear wall showed brittle characteristics with a low ductility though the bearing capacity increased by nearly 3 times. Then tested load-bearing capacities were compared with the calculation results according to standards as ACI318-14, EC8 and GB50010-2010 suitable for concrete structures to verify the applicability of the formulas for this new type shear wall. Finally, based on standard GB50010-2010, a reduction coefficient as 0.85 was used to modify the calculation results to make an accurate prediction, and the differences between the experimental and modified results were within 5%.