Seismic Testing and Numerical Analysis of Beam-Column Knee Joints in Recycled-Aggregate Concrete Frames

摘要

Post-earthquake investigations have shown that the beam-column joint is one of the weakest links in reinforced concrete moment-resisting frames under severe ground motions. An extensive study on natural aggregate concrete (NAC) beam-column joints has been conducted. However, few studies have examined the seismic performance of beam-column joints made with recycled aggregate concrete (RAC), especially for RAC roof-level exterior beam-column joints. In this paper, a series of RAC roof-level exterior beam-column joints were fabricated and subjected to reversed cyclic loadings. The ductility capacity, energy dissipation capacity, equivalent viscous damping, and load-deformation behavior of each specimen were evaluated. OpenSees was adopted to perform the finite element analyses. The numerical simulation predictions show good agreement with test results. The equations for joint shear strength determination proposed in this work exhibit a better correlation between experimental and theoretical values.