Diagonal reinforcement as strengthening to increase the stiffness and strength of concrete frame

Engineering Faculty, Civil Engineering Department, Universitas Muhammadiyah Surakarta, Indonesia

^* Corresponding author: yenny.nurchasanah@ums.ac.id

Abstract

Two test objects of concrete frame behavior against lateral loading were performed by applying structural analysis with the wall as diagonal reinforcement in modeling. The results of the structural analysis indicated that concrete frames with walls have better performance than concrete frames without walls. Twelve objects consisting of the frame without the wall, frame with the wall, and frames with a group of steel and bamboo as diagonal reinforcement at brick walls and concrete panel walls were tested at the laboratory with monotonic lateral forces that work parallel to the wall as the illustration of earthquake loads. The diagonal reinforcement elements can spread the force received by the wall and increase the strength of the wall as well as enhance the stiffness of the structural system at once. Bracing contributes to increasing the strength, especially in resisting the compressive forces due to the earthquake loads. Deformation occurs in the opposite direction between compression path and tension path at the diagonal area. The failure in the concrete frame can be caused by the in-plane force parallel to the wall. Bamboo is quite effective to be used as a substitute for steel reinforcement as bracing material despite its shortage of steel quality.