An RBS-based replaceable precast concrete beam-column joint: Design approach and experimental investigation

Abstract

In traditional reinforced concrete (RC) frame systems, severe damage usually occurs in the beam-column joint zone under strong earthquakes, which increases the post-earthquake repair difficulties in restoration speed and expenditure. In response to this problem, a new reduced beam section (RBS)-based steel beam-column joint for seismic-resistant precast concrete (PC) frames was proposed, to achieve the damage control for rapid replacement and restoration. The RBS-based beam-column joint (RBSJ) is installed in the beam end close to the column so that the plastic hinge will develop at the predetermined location. The design procedure of the replaceable RBSJ was developed, and the cyclic loading tests of two 1:2 scale specimens including a monolithic joint (MJ) specimen and a RBSJ specimen were carried out. Test results demonstrated that the proposed RBS-based joint exhibited expected failure mode and excellent hysteretic response, compared with the monolithic joint. Additionally, the damaged RBSJ specimen was subsequently replaced in situ for three times, and the quasi-static test was performed for each replaceable specimen. The test results demonstrated the replaced RBSJ specimens behaves the same behavior as the origin specimen, indicating the proposed joint was feasible in precast RC framed structures.