Investigation of strengthening effectiveness of reinforced concrete bridge with prestressed CFRP strips

Abstract

CFRP strips are commonly used for post-strengthening of various structures including bridges. In the recent years prestressed strips have been phased in due to their better effectiveness and durability as compared to non-prestressed strips. Several tensioning-anchoring kits have been developed to implement the prestressed CFRP strips technology. This paper describes implementation of a newly developed tensioning-anchoring kit and the results of experimental investigation of its effectiveness. The structural system of the bridge in question is a reinforced concrete simply supported beam with cantilevers at both sides. During the repair static load tests were carried out before and after installation of prestressed CFRP strips. The purpose of these tests was to verify the post-strengthening effect and assess the in-field performance of system. It was established that post-strengthening with prestressed CFRP strips reduced by 20-30% the stresses induced in the existing reinforcing steel and that the strips acted in combination with the existing reinforcement. The results of the performed tests have proven satisfactory effect and desired performance of the newly developed tensioning-anchoring kit.