Experimental and Numerical Study on the Shear Performance of RC Shear Walls Confined with Welded Reinforcement Grids

The prefabricated Welded Reinforcement Grids (WRG) is an alternative to the conventional hoops and cross-tie reinforcement in RC structures. Its advantages include high precision, customizability, and economization of construction time, labour and material. However, its performance as shear reinforcement of concrete shear walls has not been thoroughly studied. This paper presents an experimental investigation on the static and seismic behaviour of RC shear walls with WRG as shear reinforcement and confinement of the boundary element. For the reinforcement of long shear walls, a detailing of overlapped WRG is proposed and also tested in specimens. The stiffness, shear capacity, failure mode and the development of strain in reinforcement were instrumented and compared. The test results showed that the shear capacity of WRG confined shear walls exceeded the value predicted by the formula of Chinese code GB50010-2010, Eurocode 2 and the US code ACI 318-14. For the shear wall with overlapped WRG, no major difference was observed on its stiffness, shear capacity and failure mode. The contribution of integral WRG and overlapped WRG to the total capacity of specimens was close. The overlapped WRG was able to develop significant strain, even attain its yielding strain. The capacity of reinforcement was fully exploited and tensile force was effectively transferred. A finite element model based on MSC.Marc was established to simulate the behaviour of test specimens. The results of numerical simulation corresponded with test results with a reasonable level of accuracy.