Study On Reinforced Concrete T-beam Strengthened By External Prestressing

As an important part of the active reinforcement method, external prestressing reinforcement now is increasingly being applied in the reinforcement project. Especially for some old reinforced concrete bridges, it plays a good reinforcement effect. Compared to the other strengthening method external prestressing reinforcement has some advantages, like making parts work together, no stress lag, not affecting the traffic when applying, good strengthening effect etc. Compared with foreign countries, the study on reinforcement technology of external prestressing in China started late, resulting in a slow development. The theory and practice of the external prestressing reinforcement need further study.Relying on external prestressing reinforcement project of Pangu Bridge, this paper studies the techniques of strengthening of reinforced concrete T-beam bridge. Based on the actual project, this paper summarizes the disease and its cause of the reinforced concrete T-beam bridge which is verified by theoretical calculation. This paper studies the external prestressing reinforcement theory, designed the external prestressing reinforcement plan on this basis. Checked by the external prestress calculation theory, the results show that the reinforcement plan is rational. We used the Midas FEA to build finite element model of the anchoring device for stress analysis to verify its safety. By carrying out the monitoring, we ensured the effectiveness and safety of the process of external prestressing reinforcement. By carrying out the load test, we verified the validity of the reinforcement plan, and obtained good external prestressing reinforcement effect conclusions.Through the research, this paper concludes:external prestressing reinforcement can effectively improve the stiffness and strenghth of reinforced concrete T-beam. It can also effectively inhibit the development of cracks and improve the performance of the original bridge. It plays a certain reference value for the old bridge reinforcement.