Experimental study on seismic performance of squat precast concrete sandwich shear walls under low axial load ratio

Abstract

To improve the thermal performance and seismic resistance of structures, precast concrete sandwich shear wall (PCSSW) emerges as a promising option due to its low thermal conductivity and favorable structural performance. This study aims to examine the effectiveness of a new type of vertical connection between the PCSSW and foundation under reversed cyclic loading. The proposed vertical connection is achieved by embedding steel bars in the precast wall and foundation, respectively, followed by casting fresh concrete in place. Considering pre-embedded steel bar arrangements (single-row or double-row) and cast-in-place (CIP) concrete strength as variables, three precast specimens were designed. Seismic performance was investigated through low reversed cyclic loading tests, with a comparison made against two CIP control specimens. The results showed that the behavior of all the tested walls was governed by shear, with the ultimate bearing capacity of the PCSSW determined by the horizontal shear capacity at the weak position. Under low axial compression ratios, the specimens with double-row steel bar arrangement had higher load-carrying capacity and ductility than single-row steel bar arrangement and could be equivalent to the CIP shear walls. Results from this study were compared with the predicted values from different codes to provide some reference value for the engineering design of the proposed structure.