Strengthening of brick infilled rc frames with cfrp reinforcement-general principles

Akın, Emre
There is an excessive demand for the rehabilitation of frame type reinforced concrete (RC) buildings which do not satisfy current earthquake code provisions. Therefore, it is imperative to develop user-friendly seismic strengthening methodologies which do not necessitate the evacuation of building during rehabilitation period. In this study, it was aimed to strengthen the brick infill walls by means of diagonal Carbon Fiber-Reinforced Polymer (CFRP) fabrics and to integrate them with the existing structural frame in order to form a new lateral load resisting system. The possible effects of height to width (aspect) ratio of the infill walls and scale of the frame test specimens on the overall behavior attained by the developed rehabilitation methodology were investigated. The experimental part of the study was carried out in two steps. In the first step, ten individual panel specimens were tested in order to understand the behavior of strengthened/non-strengthened masonry walls under diagonal earthquake loads. And in the second step, the tests of eight 1/3 and four 1/2 scaled one-bay, two-story RC frames having two different aspect ratios were performed to determine design details. The experimental results were revealed in terms of lateral stiffness, strength, drift and energy dissipation characteristics of the specimens. In the analytical part, an equivalent strut and tie approach was used for modeling the strengthened/non-strengthened infill walls of the frames. The predicted pushover responses of the frame models were compared with the test results. The design criteria required for the aforementioned strengthening methodology was developed referring these analytical results.