碳纤维格栅网-UHPC 增强RC 连续梁 负弯矩区裂缝性能研究  

Research on Crack Performance in Negative Moment Zone of UHPC and Carbon Fiber Grid Reinforced RC Continuous Beam

作　　者：郭东升 刘慈军 张冠华 何化南[3] 赵育鹏 GUO Dongsheng;LIU Cijun;ZHANG Guanhua;HE Hua’nan;ZHAO Yupeng(Liaoning Province Transportation Planning and Design Institute Co.Ltd.,Shenyang 110111,China;Ningbo High-grade Highway Construction Management Center,Ningbo Zhejiang 315192,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian Liaoning 116024,China)

机构地区：[1]辽宁省交通规划设计院有限责任公司,沈阳110111 [2]宁波市高等级公路建设管理中心,浙江宁波315192 [3]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《铁道建筑》2024年第7期67-74,共8页Railway Engineering

基　　金：宁波市交通运输科技计划项目(202115)。

摘　　要：为研究碳纤维格栅网-UHPC(Ultra-High Performance Concrete)增强RC(Reinforced Concrete)连续梁负弯矩处的抗裂性能,设计7根配置不同的UHPC及碳纤维格栅网的试验梁,进行五点弯曲加载试验,分析碳纤维格栅网和UHPC的掺入、碳纤维格栅的网格尺寸、格栅的层数以及UHPC的铺设厚度等参数对负弯矩区开裂荷载和裂缝性能的影响,提出了适合碳纤维格栅网-UHPC增强的钢筋混凝土梁平均裂缝间距、裂缝宽度计算公式。试验结果表明:对照组试验梁的裂缝呈细且密的特点,有别于普通RC梁的裂缝少,宽度大;与普通RC梁相比,单独设置碳纤维格栅网、UHPC增强的试验梁负弯矩区段的开裂荷载分别提升了28.6%、85.7%,同时设置碳纤维格栅网和UHPC增强的4个试验梁分别提升了114.3%、128.6%、142.9%、171.4%;碳纤维格栅网格尺寸的减小、碳纤维格栅层数的增加、UHPC铺设厚度的增加均可以提高抗裂性能,并且使裂缝数量显著增加,裂缝间距和裂缝宽度明显减小。本文基于现有的国内外规范提出的适合碳纤维格栅网-UHPC联合加固的钢筋混凝土梁的平均裂缝间距、裂缝宽度计算值与试验值吻合较好,验证了计算公式的准确性。To investigate the crack resistance performance of carbon fiber grid-reinforced ultra-high performance concrete(UHPC)composite in the negative moment region of reinforced concrete(RC)continuous beams,this study conducted five-point bending tests on seven test beams with different configurations of UHPC and carbon fiber grill mesh,the influence of parameters such as the addition of carbon fiber grid and UHPC,grid size of carbon fiber grid,number of layers of the grid,and thickness of UHPC layer on the cracking load and crack performance in the negative moment region were analyzed.The average crack spacing and crack width formulas for reinforced concrete beams suitable for carbon fiber grid network-UHPC joint reinforcement were presented.The test results show that the cracks in the control group test beams exhibit a thin and dense pattern,which is different from the few cracks and large width pattern in ordinary RC beams.Compared with ordinary RC beams,the cracking load of the negative bending moment section of the test beam with carbon fiber mesh and UHPC reinforcement separately increased by 28.6%and 85.7%,respectively.Simultaneously setting up carbon fiber mesh and UHPC reinforced four test beams increased the cracking load by 114.3%,128.6%,142.9%,and 171.4%.Decreasing the grid size of carbon fiber grid,increasing the number of layers of carbon fiber grid,and increasing the thickness of UHPC layer can improve the crack resistance performance,and significantly increase the number of cracks while reducing the crack spacing and crack width.The average crack spacing and crack width calculation formulas for reinforced concrete beams suitable for carbon fiber grid network-UHPC joint reinforcement proposed in this paper based on existing domestic and international specifications are in good agreement with the test results,confirming the feasibility of the calculation formulas.

关 键 词：桥梁 钢筋混凝土连续梁 碳纤维格栅网 UHPC 抗裂性能 

分 类 号：U443.3[建筑科学—桥梁与隧道工程]