Grooving methods in square RC columns strengthened with longitudinal CFRP under cyclic axial compression
Grooving methods in square RC columns strengthened with longitudinal CFRP under cyclic axial compression
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DOI：
10.1016/j.engstruct.2018.08.007
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发表时间：
2018-11
影响因子：
5.5
通讯作者：
Alireza Saljoughian;D. Mostofinejad
中科院分区：
文献类型：
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作者：
Alireza Saljoughian;D. Mostofinejad
研究了纵向排列碳纤维复合材料（CFRP）在提高方形钢筋混凝土（RC）柱轴压强度和延性方面的应用。所述复合材料的整体屈曲可能导致CFRP从试样表面剥离，这阻碍了增强试样的延性和抗压强度的适当提高。为了延缓纵向CFRP板在受压状态下的屈曲，采用了最近发展起来的开槽法（GM），并与采用传统表面处理技术的外粘结加固（EBR）技术进行了比较。为此，8个方形RC柱进行循环轴压。实验参数包括纵向加固柱的技术和存在（不存在）的间歇性限制包裹。两种开槽技术，外粘结增强的凹槽（EBROG）和外粘结增强的凹槽（EBRIG），被使用。实验结果表明，相当高的贡献开槽的方法，相对于传统的EBR，限制屈曲的碳纤维布和提高柱的延性和抗压强度。结果表明，当采用GM时，FRP的抗压强度基于纵向片材中碳纤维的抗压能力的开发而提高。结果表明，在使用EBROG或EBRIG技术纵向增强的试件中，复合材料中的纤维压缩能力达到了平板试件中纤维极限拉伸强度的43.9%和69.3%，而通过EBR技术增强的柱中，该量仅为9.6%。
The current research investigates the application of carbon-fiber reinforced polymer (CFRP) composites with longitudinally aligned fibers for enhancing the compressive strength and ductility of square reinforced concrete (RC) columns under cyclic axial compression. Global buckling of the composite described may result in the debonding of CFRP off the specimen surface, which hinders proper enhancement in the ductility and compressive strength of the strengthened specimens. To postpone the buckling of the longitudinal CFRP sheets under compression, the recently developed grooving method (GM) was employed in the current research and compared with the externally bonded reinforcement (EBR) technique using the conventional surface preparation technique. For this objective, 8 square RC columns were subjected to cyclic axial compression. The experimental parameters consisted technique employed for longitudinal strengthening of the columns and the presence (absence) of intermittent confining wraps. Two grooving techniques, the externally bonded reinforcement on grooves (EBROG) and the externally bonded reinforcement in grooves (EBRIG), were used. Experimental results indicated the considerably higher contribution of the grooving method, relative to that of the conventional EBR, to limiting the buckling of CFRP sheets and to enhancing the ductility and compressive strength of the columns. It was observed that when the GM is employed, the compressive strength of FRP is enhanced based on the exploitation of the compressive capacity of the carbon fibers in the longitudinal sheets. The results illustrated that in the specimens longitudinally strengthened using the EBROG or EBRIG techniques, fiber compressive capacity in the composite reached 43.9% and 69.3% of ultimate tensile strength of fibers in flat coupons; this amount was only 9.6% for the columns strengthened through the EBR technique.