锈蚀钢筋混凝土梁粘贴钢板加固试验研究  

Experimental study on strengthening effect of bonded steel plate on corroded reinforced concrete beams

作　　者：李凤兰[1] 张军伟[1] 侯朋兵[1] 曲福来[1] 

机构地区：[1]华北水利水电大学土木与交通学院,河南郑州450011

出　　处：《混凝土》2013年第6期9-12,共4页Concrete

基　　金：国家自然科学基金(51108179);生态建筑材料河南省高校重点实验室培育基地项目(豫教科外[2009]609号)

摘　　要：制作了7根配筋率为0.81%的钢筋混凝土适筋梁,模拟既有钢筋混凝土结构在受荷后的实际状况,对其中的6根梁经预裂加载后采用电化学方法进行快速锈蚀,锈蚀试验按钢筋锈蚀率3%、6%和9%分为3组。采用粘贴钢板法对每组中的1根锈蚀钢筋混凝土梁进行了加固处理。通过加载对比试验研究表明:粘贴钢板加固锈蚀钢筋混凝土梁的正截面应变符合平截面假定,且正常使用性能得到明显改善、承载力达到了预期增强效果。粘贴钢板有效地减小了锈蚀钢筋混凝土梁的裂缝宽度和延伸高度,挠度变化呈现弹塑性变形特征,延性破坏特征明显。加固梁基本上发生钢筋钢板屈服后的受压区混凝土压碎破坏,其承载力受钢筋锈蚀率的影响较小。采用U型钢板箍辅以螺栓锚固梁底的粘贴钢板,是保证粘贴钢板与锈蚀钢筋混凝土梁协同工作的必要措施。Seven reinforced concrete beams with 0.81% reinforcement ratio were cast, and six of them were pre-cracked under loads and corroded by the electrochemical method to simulate the real status of reinforced concrete beams under loading.3 groups with 2 beams of one group were divided as 3%, 6% and 9% reinforcement corrosion ratio respectively.One of the corroded reinforced concrete beams in a group was strengthened by bonding steel plate.The comparative loading tests showed that the strains along the depth of normal cross section of beams strengthened with bonded steel plate fitted the hypothesis of plain section, the serviceability of the beams was obviously improved and the ultimate resistance reached the expected enhancement results.The bonded steel plate reduced the opening and elongation of cracks, and made the deflection change as elasto-plastic characteristic and the failure appear as ductility.All the strengthened beams basically damaged with the crushing of compressive concrete after the yielding of steel plate and steel bars, the ultimate resistances were not lost obviously with the changes of the reinforcement corrosion ratio.It is necessary to use the U-shape steel plate with bolts to anchor the bonded steel plate on the bottom of beam for their working together.

关 键 词：锈蚀钢筋混凝土梁 粘贴钢板 加固 U型钢板箍 锈蚀率 裂缝 挠度 承载力 

分 类 号：TU528.01[建筑科学—建筑技术科学]