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纤维水泥基材料常常用于锈蚀钢筋混凝土结构的修复与加固,其与锈蚀钢筋的界面粘结性能是影响修复后锈蚀构件力学性能的关键因素之一。本文针对2种用于结构修复的纤维水泥基材料(超高韧性水泥基复合材料UHTCC和钢纤维混凝土SFRC),以锈蚀率为参数,通过中心拉拔试验研究锈蚀钢筋与纤维水泥基材料的粘结性能。试验结果表明,由于纤维的桥接作用,所有UHTCC和SFRC试件均呈现为劈裂-拔出破坏模式。随着锈蚀率的增大,UHTCC试件的粘结应力-平均滑移曲线下降段更加平缓,而SFRC试件的下降段斜率基本相当。在相近的锈蚀水平,UHTCC试件的粘结强度和残余粘结强度均高于SFRC试件,锈蚀率达约14%时,UHTCC试件和SFRC试件的粘结强度分别下降至初始强度的81%和88%。此外,锈蚀对残余粘结强度的影响较小。
Fiber cement-based materials are often used in the repair and reinforcement of corroded reinforced concrete structures. The interfacial adhesion with corroded steel bars is one of the key factors that affect the mechanical properties of the repaired corroded components. In this paper, two types of fiber cement-based materials (UHTCC and SFRC) for structural restoration were studied. The corrosion rate was taken as the parameter to study the adhesion of the corrosion-resistant steel bar to the fiber cement-based material Results performance. The experimental results show that all UHTCC and SFRC specimens exhibit a splitting-pulling failure mode due to the bridging effect of the fibers. With the increase of corrosion rate, the descending section of bond-stress-average slip curve of UHTCC specimens is more gentle, while the descending slope of SFRC specimens is basically equivalent. At similar corrosion levels, the bond strength and residual bond strength of UHTCC specimens are higher than those of SFRC specimens. When the corrosion rate reaches about 14%, the bond strengths of UHTCC specimens and SFRC specimens decrease to initial strength 81% and 88%. In addition, corrosion has little effect on the residual bond strength.