用无机胶粘贴CFRP布加固混凝土梁受弯试验研究  

Experimental study on flexural behavior of concrete beams strengthened with CFRP sheets bonded with an inorganic matrix

作　　者：郑文忠[1] 陈伟宏[1] 王明敏[1] 

机构地区：[1]哈尔滨工业大学,黑龙江哈尔滨150090

出　　处：《土木工程学报》2010年第4期37-45,共9页China Civil Engineering Journal

基　　金：国家自然科学基金项目资助(50178026;50678050);教育部新世纪优秀人才支持计划资助项目(教计司[2005]290号);"十一五"国家科技支撑计划项目资助(2006BAJ03A10)

摘　　要：目前粘贴碳纤维布加固混凝土结构多采用环氧类有机胶,但其软化点过低,多为60℃～80℃。夏季由于气温高,一些地区混凝土桥梁的结构表面温度常超过环氧类有机胶的软化点,火灾下环境温度更高,用环氧类有机胶粘贴碳纤维布加固的混凝土结构难以满足耐高温要求。为此,选用600℃时强度不低于常温强度的碱矿渣胶凝材料粘贴碳纤维布,对6根混凝土简支梁进行加固,并完成了这6根梁的受力性能试验。获得了加固梁的正截面承载力、裂缝分布与开展的试验值和荷载-实测跨中挠度曲线。试验梁呈现继纵向受拉钢筋屈服后碳纤维布被拉断和纵向受拉钢筋屈服后混凝土被压碎的两种破坏模式,并且均满足平截面假定,表明用碱矿渣胶凝材料粘贴碳纤维布加固混凝土结构构件是可行的。在试验研究和理论分析的基础上,提出了用碱矿渣胶凝材料粘贴碳纤维布加固混凝土简支梁的刚度、最大裂缝宽度、正截面承载力的计算方法,基于所提方法的计算值与实测值吻合良好。At present, organic epoxy adhesives are usually used in strengthening concrete structures with carbon fiber sheets, but the softening points of organic adhesives are too low, mostly between 60℃ - 80℃. Because of high temperature in the Summer, the surface temperature on concrete bridge structures is often higher than that of the softening points of organic adhesives in some areas, and environment temperature can be much higher if in fire, the concrete structures strengthened with carbon fiber sheets using organic epoxy adhesives can not meet the heat resistance requirements. Therefore, the alkali-activaed slag cementitious materials （AASCM）, the strength of which at 600℃ is no less than that of AASCM at normal temperature, were selected to paste carbon fiber sheets for strengthening 6 simply-supported reinforced concrete beams to be tested. The test values of flexural carrying capacity of these beams, crack distribution and growth and the curve load-deflection at mid-span were obtained. Two ideal failure modes occur： one is that the tensile longitudinal steel bars yield first, then CFRP sheets break in tension; the other is that the tensile longitudinal steel bars yield first, then the extreme concrete fiber in compressive region reaches the ultimate strain. The plane-section assumption is applicable. The experimental results show that it is feasible to strengthen concrete members with CFRP sheets bonded with AASCM. The calculation formulas of stiffness, maximum crack width and flexural load-carrying capacity of concrete simply supported beams strengthened with CFRP sheets bonded with AASCM were established based on the experimental results and theoretical study. The calculated results are in good agreement with the experimental ones.

关 键 词：碱矿渣胶凝材料 耐高温 碳纤维布 加固 混凝土梁 

分 类 号：TU375.1[建筑科学—结构工程]