Study On The Compressive Behavior Of GFRP Bars And GFRP Reinforced Concrete Columns

The previous studies and engineering practice have proved that, using the Fiber ReinforcedPolymer (abbr. FRP) as the reinforcements for concrete structures can effectively prevent thecorrosion problems of steel. However, due to the limitations of material properties and theinfluence of conventional theories, the study on compression performance of FRP has made onlylimited achievements. The lake of compression data on FRP limits its application in thereinforced concrete compression members with FRP bars. Therefore, a comprehensive andsystematic study on compression performance of FRP is urgently needed, and it had importantsignificance toward the expansion application.In this paper, the studies of the compression performance of GFRP bars were conducted.The accelerated simulation experiments on alkali, chloride salt solution were made. Throughmaterial apparent conditions, mechanical properties, microscopic changes in the structure, thecorrosion mechanism and laws were analyzed. Based on the test results of the performance ofGFRP bars, the studies of the axial performance were carried out.Test results show that the GFRP bars have the performance of the high strength and thelarge ultimate strain of compression, and the stress strain curve expresses as approximate lines. Itis also indicated that with the length-diameter ratio of2.5during testing should be well preventlocal failure. The influence of the chloride salt corrosion on the compression performance ofGFRP bars is little, but it is obvious on the alkali corrosion. Along with the duration of corrosion,the performance declined furthermore, the sample with alkali corrosion only processes50%residual strength of the compression after90d. For the wet-dry cycling environment, the shortstage effect in GFRP bars was similar with chloride salt corrosion, but for longer exposure time,the effect on GFRP bars by wet-dry cycling was more sever than chloride salt corrosion. The testresults shows that the concrete columns reinforced with GFRP bars have high load-bearing. Thecompressive concrete will be crushed first, and the GFRP bars are still undamaged. Thecompression capacity would increase with the reinforcement ratio in the certain scope.Especially, it establish a good foundation for the next step of more in-depth, comprehensiveand systemic researching on this field。...