The Pushout Test of Seismic Reinforcement System (SRM) Connection that Respond to Earthquake Extensive Level

This paper introduces a state-of-the art seismic retrofit method (SRM) that has the resistance mechanism of eccentrically braced frames (EBF). In EBF, local failure is induced to the link beam such that other members remain in the elastic state when an earthquake load is applied. SRM works by attaching to an existing building in the form of an external frame to enhance its seismic performance. The seismic reinforcement of medium- and low-rise reinforced concrete buildings has a small inter-story drift; hence, the adhesion between the two materials has a great influence on the seismic reinforcement effect. In this study, a push-out test was performed to show the adhesion performance under various conditions. The performance of various attachment methods was also explored to improve adhesion with the RC structure for securing the performance of the SRM system. Additionally, this study proposes a shear strength equation that considers the influence of the contact direction of steel, increase in plate thickness, and anchor yield strength. The test results indicated that it can be used as a new shear strength equation as the error rate is within 10% compared to the experimental results. Although the web direct bonding method using end plates is disadvantageous in terms of processability, it showed the highest strength improvement results. Furthermore, the chemical anchor (Hilti) connection exhibited stable performance results regardless of the bonding method.