Experimental Study On Reinforced Concrete Beams Strengthened By Composite Cover Of High Strength Wire Cable Mesh And Polymer Mortar

There is a great number of dangerous and old bridges in our country, which are in deviant service. It has important society significance to maintain, strengthen, rehabilitate the existing bridges for the purpose of keeping their serviceability, extending their service life, and accomplishing the sustainable development. The composite cover of high strength wire mesh and polymer mortar is a new applicated technology for strengthening concrete structures in recent years, which possess advantanges of high-strength, fire-resistance, corrupt-protection, anti-aging, strong polymerization, non-pollution, and easy construction,etc. So this technology seems to be widely application market. This paper focuses on the study on the flexural behavior of concrete beams strengthened with the composite cover of high strength wire mesh and polymer mortar. The main works included as follows: (1) Construction strengthening technology by using high strength wire mesh (HSWM) and polymer mortar (PM) was explored. (2) 8-pieces reinforced concrete (RC) beams and 8-pieces pre-stressing reinforced concrete (PRC) beams strengthened by HSWM-PM were tested under flexural loading. (3) The flexural behaviors of RC beams and PRC beams strengthened by HSWM-PM were analyzed and compared. (4) The flexural behaviors of damaged RC beams and damaged PRC beams strengthened by HSWM-PM were analyzed and compared. (5) The similarities and differences of danaged beams strengthened by HSWM-PM and by gluing steel plates were analyzed and compared. (6) The simplified calculation methods of flexural behavior for RC and PRC beams strengthened by HSWM-PM were studied. Some important conclusions were extracted from the experiments and analysis and lised in the following: (1) The strengthening method by using HSWM-PM can restrain cracks development, improve the load-carrying capacity and cracking load, and enhance the flexural stiffness of RC beams and PRC beams. (2) Load history will effect the cracking load, the flexural stiffness and ductility of the strengthened RC beams. But it is not obvious in the flexural stiffness and ductility for the strengthened PRC beams. (3) Because of high-level content of steel plate, the load-carrying capacity and the flexural stiffness of RC beams and PRC beams strengthened by gluing steel plates are grater than those of RC beams and PRC beams strengthened by HSWM-PM. But the ductilities of the members strengthened by gluing steel plates are lower than that of RC beams and PRC beams strengthened by HSWM-PM. (4) The simplied calculation models of the ultimate load-carrying capacity, cracking load, and flexural stiffness and deflection for the damaged RC and PRC beams strengthened by HSWM-PM were proposed, and the prediction results from these models agree well with those of testing. These calculation models can be used to strengthening design of RC beams and PRC beams by using the high strength wire mesh and polymer mortar.