Experimental study on seismic performance of resilient recycled aggregate concrete shear walls

A type of recycled aggregate concrete shear wall was proposed in this work, which used the painted ultra-high-strength steel (UHSS) reinforcements with low bond strength and high yield strength in the boundary elements. For investigating the seismic resistance and resilient performance of this shear wall, six shear walls with the shear-to-span ratio of 1.5 were fabricated and tested under the cyclic loads. The variables studied in this paper were the types of the longitudinal reinforcement in the boundary elements, the existence of steel fibers, the presence of the concealed bracings (X-shaped) and the different axial compression ratios. The test results indi-cated that specimens with the UHSS reinforcement in the boundary elements decreased the residual deformation substantially and improved the resilient properties. The higher axial compression ratio enhanced lateral force resistance of shear wall but aggravated concrete damage which was adverse to the resilience. In addition, the utilization of steel fibers in concrete significantly reduced the crack width. The shear wall including concealed bracing not only showed much higher lateral force resistance, but also had desirable resilient performance under the large deformation. Finally, a simplified calculation model for such shear walls was proposed on the basis of experiment. And the good accuracy of the calculation model was verified by comparing the calculation results and the measured results.

Automated summary

A type of recycled aggregate concrete shear wall using painted ultra-high-strength steel reinforcements has been proposed and experimentally investigated in this study. The results showed that the use of ultra-high-strength steel reinforcements in the boundary elements significantly reduced residual deformation and improved the resilient properties. Higher axial compression ratios enhanced lateral force resistance but aggravated concrete damage, which was detrimental to resilience. The inclusion of steel fibers in concrete effectively reduced crack width. Shear walls with concealed bracings exhibited higher lateral force resistance and desirable resilient performance under large deformation. A simplified calculation model for such shear walls was also proposed and validated.