冻融循环下CFRP—高性能混凝土的粘结性能

发布时间：2018-08-19 13:50

【摘要】：通过双面剪切试验,研究了冻融环境下CFRP-高性能混凝土界面粘结性能的发展规律。对比分析了未经冻融和经历25、50、100、150、200及300次冻融循环作用试件的破坏特征、剪应变分布、荷载滑移曲线、粘结承载力以及粘结破坏机理。结果表明,所有试件的界面破坏均发生在混凝土表层内,但随着冻融循环次数的增加,破坏界面有向胶层发展的趋势;经受冻融循环次数较少时(25、50次),界面的粘结强度、刚度及开裂荷载的变化不明显,甚至略微提高;但随着冻融循环次数的进一步增加,界面粘结性能有明显的变化,界面粘结强度、端部滑移量减小,刚度退化,初始开裂荷载水平降低,非线性特征增强。粘结极限承载力与混凝土立方体抗压强度均随冻融循环次数的增长存在先提高后下降的趋势,混凝土强度变化是界面粘结性能变化的最重要因素。
[Abstract]:The development of interfacial bond behavior of CFRP- high performance concrete under freezing and thawing environment was studied by double shear test. The failure characteristics, shear strain distribution, load-slip curve, bond bearing capacity and bond failure mechanism of specimens without freeze-thaw and 2550100150200 and 300 freeze-thaw cycles were compared and analyzed. The results show that the interfacial failure of all specimens occurs in the surface layer of concrete, but with the increase of freeze-thaw cycles, the failure interface tends to develop towards the adhesive layer, and when the number of freeze-thaw cycles is less (2550 times), the bond strength of the interface is increased. The change of stiffness and cracking load is not obvious, or even slightly increased, but with the further increase of freeze-thaw cycle, the interfacial bond property has obvious change, the interfacial bond strength, the slip at the end decreases, and the stiffness degenerates. The initial cracking load level is reduced and the nonlinear characteristic is enhanced. The ultimate bearing capacity of bond and the compressive strength of concrete cube increase first and then decrease with the increase of freeze-thaw cycle times. The change of concrete strength is the most important factor of the change of interfacial bond performance.
【作者单位】：青岛理工大学蓝色经济区工程建设与安全协同创新中心;青岛理工大学土木工程学院;
【基金】：国家重点国际合作项目(51420105015) 青岛市基础研究—联合基金计划项目(13-1-4-115-jch)~~
【分类号】：TU528

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