Long-Term Flexural Performance of Prestressed-NSM-CFRP Strengthened RC Beams.

摘要

The use of prestressed Fibre Reinforced Polymer (FRP) for strengthening structural members requires gaining further knowledge about the long-term behaviour of these members. In this research, the long-term flexural performance of the prestressed Near-Surface Mounted (NSM) Carbon Fibre Reinforced Polymer (CFRP) strengthened Reinforced Concrete (RC) beams subjected to accelerated environmental exposure and sustained load condition was studied. The static behaviour of the exposed and unexposed beams was predicted numerically and analytically, and the predicted results were compared with the experimental ones. The prestressing system used for tensioning the NSM CFRP reinforcements was modified. The prestress loss in the NSM CFRP reinforcements was studied. Deformability and ductility of the prestressed NSM CFRP strengthened RC beams were studied in detail. Furthermore, the effects of the different parameters on the flexural behaviour of the NSM CFRP strengthened RC beams and on the pullout capacity of the anchorage system used for prestressing were investigated numerically. The findings showed the significant effect of the applied exposure on the flexural performance of the beams, and furthermore, the high reliability of the developed numerical and analytical models for simulation of the static flexural behaviour of the exposed and unexposed beams. The results of this research lead to an understanding of the long-term flexural behave iour of the RC beams strengthened using prestressed NSM CFRP reinforcements and pursue the evolution of this strengthening system to be used in practical projects with sufficient confidence,