Experimental Study on Shear Behavior of Precast Shear Wall with Composite Alveolar Connections

To study the influence of the cross-sectional area of reinforcement and H-beam shear key on the shear performance of concrete walls, three full-scale prefabricated low-shear wall specimens with a shear span ratio of 0.87 were designed and manufactured. This paper mainly studies the failure process and ultimate failure mode, load characteristic value and load displacement curve of three shear wall specimens under monotonic push load under the condition that the vertical axial pressure remains unchanged. The effects of three different structural treatments on the shear performance of the specimens were compared and analyzed, which were common roughening at the interface of the new and old concrete, increasing the cross-sectional area of the steel bar and adding the H-shaped steel shear key. It is observed that the three specimens exhibit similar failure processes and final failure modes: ① the tensile yield or the even break of the reinforcement at the root of the concealed column on the right side of the shear wall specimen, ② the collapse and fall of the concrete at the root of the concealed column on the left side, and ③ the horizontal cracks at the joint surface, which are the main cracks. Results show that the U-shaped steel bar lap joint of the three shear wall specimens at the composite alveolar can effectively transfer the stress. Moreover, increasing the cross-sectional area of the steel bar at the joint surface and adding the H-shaped steel shear key can improve the shear bearing capacity of the specimens with a peak bearing capacity of 773.4 kN, 950.3 kN and 925.3 kN for YZW-1, YZW-2, and YZW-3, respectively. The ultimate bearing capacity of YZW-2 increases by 22.9% when the cross-sectional area of reinforcement is increased, while the ultimate bearing capacity of YZW-3 with H-beam is increased by 19.7%. Comparison results of the load-displacement curves of the three specimens reveal that YZW-2 exhibits a higher stiffness and stronger lateral displacement resistance compared to those of YZW-1, and is easy to operate in the actual construction process. Compared with YZW-1, YZW-3 with an added H-beam has the same stiffness but stronger ultimate deformation capacity in the later stage. © 2022, Editorial Board of Journal of Tianjin University(Science and Technology). All right reserved.