硫酸盐半浸泡下CFRP-砌体界面粘结性能试验研究

Experimental Investigation on the Interface Bonding Performance between CFRP and Masonry under Sulfate Semi-immersion

为探究硫酸盐半浸泡环境对CFRP-砌体界面粘结性能的影响,对不同侵蚀天数下的加固砌体短柱进行单面剪切试验,研究了10%硫酸钠溶液持续半浸泡环境下CFRP-砌体和CFRP-预劣化砌体的界面粘结性能。结果表明:粘结界面破坏形态主要表现为FRP层破坏、树脂胶粘结层破坏和砖基体破坏。CFRP-砌体的界面破坏形态随着浸泡天数的增长由FRP层破坏逐渐过渡为砖基体破坏,CFRP-预劣化砌体由FRP层破坏逐渐过渡为树脂胶粘结层破坏。硫酸盐环境下界面极限承载力与粘结强度随着半浸泡天数的增加而降低,半浸泡90 d后,CFRP-砌体的极限承载力和粘结强度分别降低了24.6%和43%,而CFRP-预劣化砌体的降低幅度最大达到了65.8%。这表明在盐侵蚀劣化砌体表面粘贴CFRP时,劣化表面可能会对固化过程产生不利,进而影响粘结性能。此研究将为受硫酸盐侵蚀较为严重的地区使用CFRP加固砌体结构提供参考。

To investigate the effect of sulphate semi-immersion environment on the interfacial bonding properties of CFRP-masonry,one-sided shear tests were conducted on short columns of reinforced masonry under different erosion days,and the interfacial bonding properties of CFRP-masonry and CFRP-pre-deteriorated masonry were investigated under continuous semi-immersion environment of 10% sodium sulphate solution.The results show that the interfacial damage patterns are mainly FRP layer damage,resin-adhesive bond layer damage and brick matrix damage,and the interfacial damage patterns of CFRP-masonry gradually transitioned from FRP layer damage to brick matrix damage with the increase of immersion days,and CFRP-pre-deteriorated masonry gradually transitioned from FRP layer damage to resin-adhesive bond layer damage.The ultimate load carrying capacity and bond strength of the interface in the sulphate environment decreased with the increase of the number of half-immersion days,and after 90 d of half-immersion,the ultimate load carrying capacity and bond strength of CFRP-masonry decreased by 24.6% and 43%,respectively,whereas the decrease of CFRP-pre-deteriorated masonry reached the maximum of 65.8%.This suggests that when CFRP is adhered to salt attack deteriorated masonry surfaces,the deteriorated surfaces may be detrimental to the curing process,which in turn affects the bond performance.This study will provide a reference for the use of CFRP to strengthen masonry structures in areas subject to more severe sulphate erosion.