配纤率对CFRP布加固大尺寸混凝土梁受剪性能影响试验研究  

Experimental study on effect of CFRP ratio on shear performance of large-size concrete beams wrapped with CFRP sheets

作　　者：蒋轩昂 金浏[1] 杜修力[1] JIANG Xuanang;JIN Liu;DU Xiuli(The Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《建筑结构学报》2023年第7期172-182,共11页Journal of Building Structures

基　　金：国家重点研发计划项目(2018YFC1504302);国家自然科学基金项目(51822801)。

摘　　要：为了分析CFRP配纤率对大尺寸CFRP加固梁(梁高超过600 mm)破坏模式及受剪承载力的影响,以及CFRP在大尺寸加固梁中的作用,设计了4根剪跨比为1.5、配纤率为0~0.2505%的大尺寸(梁高1200 mm)U形CFRP布包裹无腹筋钢筋混凝土梁(混凝土立方体抗压强度fcu为49 MPa)试验。研究结果表明:不同CFRP配纤率下加固梁受剪承载力分别提高57%、72%、77%,但随着配纤率增大,CFRP的抗剪加固效率系数下降,其值分别为57%、10%和3%,说明碳纤维材料对梁受剪承载能力的增强不会随着CFRP的用量增大而线性增加;通过分析CFRP布的抗剪贡献,发现CFRP的抗剪贡献随CFRP配纤率的增大而逐渐增加,但加固效率呈现下降趋势。结合试验结果对相关设计规范受剪承载力计算公式的准确性和安全性进行了分析,其中,欧洲规范(fib-TG 9.32001)最为保守,中国规范(GB 50367—2013)计算值最接近试验值。In order to analyze the effects of CFRP ratio on the failure mode and shear capacity of large-size(beam height over 600 mm)beams strengthened by CFRP,as well as the effect of CFRP in large-size beams wrapped by CFRP,experimental investigation of four large size(beam height 1200 mm)U-shaped CFRP wrapped non-abdominal reinforced concrete beams(concrete strength 49 MPa)with shear span ratio of 1.5 and CFRP ratio of 0~0.2505%was designed.The results show that the shear capacity of beams strengthened with different CFRP ratios increases by 57%,72%and 77%,respectively.However,with the increase of the CFRP ratio,the shear strengthening efficiency of CFRP decreases by 57%,10%,and 3%,respectively.It indicates that the enhancement of the shear capacity of strengthened beams does not linearly increase with the increase of the amount of CFRP.In addition,it is found that the shear contribution of CFRP increases with the increase of CFRP ratio,but the strengthening efficiency shows a decreasing trend.The accuracy and safety of the calculation formula of shear capacity of relevant design specifications were discussed based on the test results.The European specification(fib-TG 9.32001)is the most conservative,and the Chinese specification(GB 50367—2013)is the closest to the test value.

关 键 词：混凝土梁 大尺寸 配纤率 静力试验 受剪性能 抗剪贡献 

分 类 号：TU375.1[建筑科学—结构工程] TU528.1TU317.1