Research On Mechanical Properties Of Damaged Reinforced Concrete Beams Strengthened By CFRP Under Freeze-thaw Environment

With the practical application of FRP reinforcement increasing civil engineering, carbon fiber(CFRP) Reinforcement Project also been widely used, but the long-term strengthening CFRP performance still has not been fully verified, especially in our country northern region, due to the winter weather is cold, freeze-thaw cycles of destruction is the main reason for the destruction of concrete structures, while in reality Reinforcement Project, when using CFRP, need reinforcement structure has generally been too long already under load or loads for a long time. Therefore, before CFRP reinforced concrete beams has been subjected to a pre-loaded in-depth study of this aspect more realistic reality strengthening works on later in life actually strengthening works of great significance.In this paper, by laboratory tests and finite element software simulation of two parts, the main research after freeze-thaw cycles CFRP reinforced concrete beams damaged mechanical properties studied are as follows:1, with the CFRP preloaded different degrees of reinforced concrete beams, and after reinforcement beams to destroy the test load test, the experimental results show that the pre-loaded reinforced concrete beams after pasting CFRP flexural rigidity was increase to a certain extent, the same as the different layers of CFRP pasted beam bending performance played an effective increase under extent of the damage. The beam shear test performance due to CFRP beam bottom position is, therefore, from the experimental results of performance test beam shear increase is not very obvious.2, making concrete trabecular 100 × 100 × 400, and to carry out the trabecular CFRP processing, 《 ordinary concrete long-term performance and durability test method 》(GB50082-2009)after reinforcement reference in fast freeze frost resistance test method performed, the number of freeze-thaw 25,50,75,100 respectively, results showed that with the freeze-thaw cycles increases the flexural strength decreased, but at the same freeze-thaw cycles with CFRP layers increase Large and reinforcement approach, the flexural strength of concrete beams increases.3, using the finite element software after freezing damage to the mechanical properties of CFRP reinforced concrete beam tests were simulated. Finite element results are consistent with the law better, and after freezing damage to reinforced concrete beam reinforcement design can learn from.