Prestressed Experiment Study And Mechanism Analysis Of BFRP Sheet Reinforing Steel Pipeline

Prestressed FRP reinforcing steel pipe can be fully play to the superior performance of FRP, and can solve the problem of stress lag of FRP sheet. In prestressed FRP sheet reinforcing steel pipeline, the tension and anchorage of prestress is an important and urgent problem to be solved, study on the prestress loss is also one of the key technology in prestressed FRP reinforcement.Therefore the special study on anchor for prestressed FRP is very necessary.Based on the mechanical properties of FRP reinforcing metal pipeline, this paper developed a new-style stretching and anchoring integral device for prestressed FRP sheet, and carried out the experiment of prestress tensioning and anchorage performance. The results showed that FRP can be prestessed by rotating the anchor rod, and that the bolts can effectively anchor the sheet.Meanwhile, according to the new prestressed anchor proposed previously,this paper analysed the generation mechanism of friction loss, anchorage loss,relaxation loss caused by the strengthening process. By Elastic-plastic mechanical plane stress solution and friction loss test research, the stress distribution of fiber sheet after the friction loss is established. Be based on the analysis of relaxation loss test and anchorage loss test, finding that the anchorage loss exist in the first 80 minutes of the process and that the anchorage loss is related to the locking degree of bolt. Besides acquiring the relaxation loss percentage and the change law of relaxation loss with the time. Finally, analysed the failure characteristics of FRP sheet without epoxy resin; providing a reference for prestressed FRP reinforced steel pipeline theory.