冻融循环对FRP片材-砌块界面粘结性能的影响

Effect of freeze-thaw cycles on bond properties of FRP sheet-brick

  • 摘要: 研究了冻融循环对纤维增强树脂复合材料(FRP)加固砌块界面粘结性能的影响,分别采用碳纤维增强树脂复合材料(CFRP)片材和玻璃纤维增强树脂复合材料(GFRP)片材对烧结黏土砖和页岩砖进行了加固,通过试验研究了不同冻融次数条件下砖、砂浆、FRP片材和树脂各种材料性能的变化及FRP片材与砌体间的正拉粘结强度和单面剪切强度的变化规律。研究结果表明,冻融循环对黏土砖、页岩砖、砂浆块、CFRP片材、GFRP片材和粘贴环氧树脂的力学性能产生了显著的影响,均随着冻融次数的增加而明显降低;FRP片材与砖砌块界面间的正拉粘结强度和单面剪切强度随着冻融循环次数的增加而逐渐降低,经过30次冻融循环后FRP片材加固单砖的正拉粘结强度最大会降低45.49%,单面剪切强度最大可降低42.26%;FRP片材的种类对不同冻融次数条件下FRP片材-砌体的正拉粘结强度几乎没有影响,但对单面剪切强度有一定的影响。

     

    Abstract: The effect of freeze-thaw cycles on the interfacial bonding properties of fiber reinforced polymer (FRP) sheet reinforced blocks was studied. Two kinds of fiber sheets, carbon fiber reinforced polymer (CFRP) sheet and glass fiber reinforced polymer (GFRP) sheet, were used to strengthen clay brick and shale brick respectively. The tests of various material properties, pull-off bond and single-lap shear bond were carried out to study the effect of freeze-thaw times. The results show that the mechanical properties of clay brick, shale brick, mortar block, CFRP sheet, GFRP sheet and epoxy resin are seriously affected by freeze-thaw cycles, and all decrease significantly with the increase of freeze-thaw times. The pull-off bond strength and single-lap shear bond strength of FRP sheet and brick gradually decrease with the increase of freeze-thaw times. After 30 freeze-thaw cycles, the pull-off debonding force of FRP sheet and brick block is reduced by 45.49%, and the single-lap shear bond strength of FRP sheet and brick block is reduced by 42.26%. The type of FRP sheet has little effect on the pull-off bond strength under different freeze-thaw times, but has a certain effect on the single-lap shear bond strength.

     

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