箱形混凝土梁粘贴碳纤维布的受弯承载力  

Flexural bearing capacity of box-type concrete beam with CFRP

作　　者：张延年[1] 李朝阳[1] 刘新[1] 刘金升[1] 郑怡 刘春发[3] 

机构地区：[1]沈阳建筑大学土木工程学院,辽宁沈阳110168 [2]辽宁省建筑材料监督检验院,辽宁沈阳110032 [3]沈阳市政集团有限公司,辽宁沈阳110021

出　　处：《江苏大学学报（自然科学版）》2015年第5期604-609,共6页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51078065);辽宁省高等学校优秀人才支持计划项目(LR2014015);重庆市科技计划项目(cstc2013yykf A30004);沈阳市科技计划项目(F12-271-4-00)

摘　　要：为研究箱形混凝土梁粘贴碳纤维布后的受弯性能及承载力,对8根不同混凝土强度、配筋率、碳纤维布加固量、U形箍间距的混凝土梁进行试验.研究结果表明:粘贴碳纤维布能够有效改善梁受弯性能,提高梁的屈服荷载和极限荷载,能够充分发挥其高强特性,得到了很好的加固效果;由于粘贴碳纤维布属于被动加固,且材料很薄,在加载初期发挥的作用很小,故对梁的开裂荷载影响较小;该加固方法对屈服前梁的刚度影响很小,屈服后梁的刚度有一定的提高;标准梁受压区高度x≤2a's时,由于混凝土不参加计算,故无需考虑箱形梁的特殊截面,设计时可采用《混凝土结构设计规范》中矩形截面梁的计算公式,计算精度较高;碳纤维布加固梁在受压区高度x≤2a's时,参照《公路桥梁加固设计规范》中计算公式,但计算精度不高,通过对折减系数的修正,能够使计算结果更加精确.To investigate the bearing capacity and bending performance of box-type concrete beam strengthened with CFRP,the experiments of 8 reinforced concrete beams with different concrete strength,reinforcement ratio,CFRP amount and U hoop spacing were conducted. The results show that the bending performance of beam can be effectively improved by CFRP with increased yield load and ultimate load,and the strength properties can be fully played with good reinforcing effect. Because reinforcement of CFRP belongs to passive strengthening,the thin material has slight effect in the initial stage of loading with little impact on the crack load. The strengthening method has little influence on the stiffness before beam yield,while the rigidity is improved after yield. When the compression zone height x of standard beam is less than 2a＇s,the special section of box-type beam does not need to be considered because theconcrete does not participate in the calculation. The code for design of concrete structure on the beam of rectangular cross section formula specification can be used for the design with high accuracy.Specification of JTG J22—2008T calculation formula can be referred when the compression zone height x of strengthened beam with CFRP is less than 2a＇s,but the accuracy is not high. The corrected reduction coefficient can improve the accuracy of results.

关 键 词：混凝土结构 箱形梁 碳纤维布 受弯性能 承载力 

分 类 号：TU375.1[建筑科学—结构工程]