EXPERIMENTAL STUDY ON RESTORING FORCE MODEL FOR STEEL-POLYPROPYLENE-FIBER-REINFORCED CONCRETE SHEAR WALLS WITH LITHIUM SLAG

In order to study the seismic performance and restoring force characteristics of steel-polypropylene-fiber-reinforced concrete shear wall with lithium slag, three shear walls were tested by quasi-static test. The components had gone through the elastic stage, elastic-plastic stage, yield stage, and failure stage. Based on test results, taking cracking points, yield points, peak points and breaking-down points as characteristic points, the stress form and failure results of the specimen were analyzed, and the four-fold-line skeleton curve model, stiffness degradation law and restoring force model of the new shear wall were proposed. The results showed that under the same axial compression ratio, the hybrid fiber could effectively improve the ductility and ultimate deformation capacity of the component. As the axial compression ratio increased, the specimen mixed with the hybrid fiber would increase the bearing capacity and ductility, reduce the residual deformation and stiffness. According to the test results, the four-fold-line skeleton curve model fitted well with the test results, which could better reflect the stress state of the specimen at each stage. The stiffness degradation equation established by regressive and theoretical analysis of test data could better describe the stiffness degradation law of members at each stage. The restoring force model based on the hysteresis rule was preposed.