Flexural behavior of prestressed CFRP reinforced RC beams with secondary stress

In this paper, the leading and lagging strain relationship under prestressed CFRP is analyzed. By modifying the formula of the calculation model of the debonding bearing capacity based on the adjustment coefficients related to temperature and humidity, the calculation method of the flexural bearing capacity of the prestressed CFRP reinforced concrete beam when the debonding failure occurs under the indoor environment and high temperature environment is obtained. The flexural properties of CFRP reinforced specimens are compared with those of other composite materials. The enhancement effects of different reinforcement schemes on flexural performance were discussed. The results show that the calculated value of flexural ultimate bearing capacity of prestressed CFRP reinforced concrete beams under secondary stress is slightly less than the experimental value, and the calculated value is safe. When the reinforced beam is in a hot and humid environment, the change of temperature and humidity will deteriorate the interface performance, which will affect the occurrence time of stripping failure. The higher the temperature and humidity, the greater the degree of interface damage under the same load, and the faster the stripping time of CFRP. The bolt mechanical anchoring reinforcement scheme proposed in this paper can well play the reinforcement effect of the CFRP plate. The flexural performance is sensitive to the variable parameters of the anchoring scheme. In the reinforcement scheme, better anchoring effect can be obtained by changing the anchoring position and number of bolts. The application of this method in practical reinforcement engineering is meaningful.