Research Of The Craft Prestressing CFRP Boads And The Stress Loss Of The Prestressed CFRP Boads

The method of strengthening technology using prestressed CFRP has been used in civil engineering. But anchoring and prestressing the corbon fiber sheets have been the two hung-ups for a long time. Zhuo Jing invented the Wave-shaped-gear-grip(WSGG) anchorage for this reason. Zhuo Jing's researchs have proved that the WSGG anchorage is a effective anchorage for the FRP sheets. But he did not make out the construction technics of prestressing the FRP sheets, and he also did not reseash the stress loss of the prestressed CFRPS.For this actuality , we use a 5.7m long steel beam as a pedestal and the WSGG anchoage as the anchoring and the prestessing implement exploring the technics of prestessing the FRP sheets and researching the problem the stess loss. The reason using the steel beam as the pedestal is that the steel beam can be reused , so it can avoid the unnecessary waste.After the research on six members, we have fished out a simple and easy prestressing construction technics for the FRP sheets. This technics consists of four construction process, these are: (1)fixing the WSGG anchor; (2)making the CFRP sheets; (3)anchoring the CFRP sheets; (4)tensioning the CFRP sheets. According observing the strain of the prestressed CFRP sheets of three members, we have known that in the first two days the long time stress loss of prestressed CFRP sheets is most is the most rapid, and the quantity of the stess loss in the first two days in also the most which is more than 70 percent of the total quantity of the stress loss which is less than 10 percent of the total valid prestress of the CFRP sheets. According the durability test , we have known that the anchoring effect of the WSGG anchor can not fail at the 130 centigrade degree.The WSGG anchor is a new and practical anchoring and prestessing implement for the FRP sheets, which has high academic value and practical value and is hoped to be applied popularly in civil engineering.