Testing Research On The Durability Behaviors Of Glass Fiber Plastics Reinforced Concrete Columns

Fiber reinforced plastics (FRP) is a new building and reinforcing material,which has been taken widely attention in the civil engineering due to several strongpoints: high strength-weight ratio , low expand quotiety(e.p. the quotiety of GFRP is the same as the concrete's),anisotropism light weight, high corrosion resistance, nonmagnetic, well fatigue resistance and high durability. At present, it's application in the civil engineering was mature. In the end of 1990s, our country started studying it, especially, the study of external reinforcing concrete by bonding the FRP is the most important. In this paper, combined with the key program "The special project of prior research of national greatbasic research ------durability of FRP — reinforced concrete members in severeconditions ", and there are little studies about the durability of FRP reinforcing concrete-structures, a series of tests about it have been completed, and many conclusionhave been obtained.1. The tensile property of glass fiber sheets in typical environments such as carbonization dry/wet cycles was tested ,and tensile strength, elastic modulus and elongation of GFRP versus these typical environments were measured. Results showed that the tensile property of glass fiber reinforced plastic in typical environments has an important relation with the type of adhesive , the time of carbonization and the times of dry/wet cycles.2. The shear bond performance in several typical environments such as carbonization, dry/wet cycles was tested, and the effect that the environments affect the bond between GFRP and concrete was measured. The result shows that carbonization causes the bond strength depressing, dry/wet cycles have a bad influence on the bond behavior between GFRP and concrete.3. The upright pull bong performance in the same typical environments was tested, and the effect that the environments affect the bond between GFRP and concrete was measured. The result shows that the two environments causes the upright pull bond strength declining and the change of failure form.4. Based on the test results of 40 columns strengthened by externally bonding GFRP in the two environments, the performance of axial express was discussed. The influence about the environments affecting the axial compressive performance of the specimens and a formula on the axial compressive strength of columns strengthened with GFRP exposed in the two environments.