基于气体渗透技术的混凝土板梁裂缝状态评估研究  

Study of Crack State Evaluation for Concrete Hollow Slab Girder Based on Gas Permeability Technology

作　　者：韩依璇 王晓东 程才 张国荣 陈伟[3] HAN Yi-xuan;WANG Xiao-dong;CHENG Cai;ZHANG Guo-rong;CHEN Wei(State Key Laboratory of Safety and Health for In-service Long Span Bridges,Nanjing 211112,China;Suzhou Highway Administration Department,Suzhou 215004,China;Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]在役长大桥梁安全与健康国家重点实验室,江苏南京211112 [2]苏州市公路管理处,江苏苏州215004 [3]湖北工业大学,湖北武汉430068

出　　处：《世界桥梁》2020年第6期77-83,共7页World Bridges

基　　金：江苏省自然科学基金青年基金项目(BK20160144);湖北省自然科学基金面上项目(2017CFB604)。

摘　　要：针对预应力混凝土空心板梁的裂缝病害,以太仓市塘泾河桥——3×20 m预应力混凝土简支空心板梁桥为背景,利用气体渗透技术,进行气体渗透系数与裂缝宽度闭合量关系试验,并在实桥上跟踪观测裂缝状态变化,评估构件混凝土的密实度和施工质量。室内试验结果表明:混凝土气体渗透系数与裂缝宽度闭合量具有良好的相关性,当裂缝宽度闭合量增减10μm时,气体渗透系数伴随1个数量级的变化。现场测试发现:实桥边跨中板梁端顶部气体渗透系数变化大于1个数量级的差异,证明此处可能出现细观裂缝,且裂缝宽度增大了约10μm;边板四分点顶部气体渗透系数变化呈现超越2个数量级的显著升高,证明施工可能对此位置造成宏观裂缝或孔洞缺陷。气体渗透系数能够较好地反映混凝土裂缝状态和密实性能变化。To address the cracking deterioration of prestressed concrete hollow slab girder,the Tangjing River Bridge in Taicang City,which is a simply-supported prestressed concrete hollow slab girder bridge with three spans of 20 m,is cited as a case.The gas permeability testing was conducted to examine the relationship between gas permeability and crack width closure,and the crack state in the real bridge was monitored,to evaluate the compactness of concrete components and construction quality.The results of indoor testing demonstrate that the gas permeability of concrete is well correlated with the crack width closure,suggesting that either 10μm increase or 10μm decrease of crack width closure will lead to an order of magnitude of permeability change.In addition,the field monitoring shows that the change of gas permeability at the top of girder end in the middle slab of side span is more than an order of magnitude,indicating the appearance of meso-cracks,and the crack width is increased by about 10μm.The gas permeabilities at the top of quarter point in the side slab are remarkably decreased in excess of two orders of magnitude,meaning that macro-cracks and voids might occur in that place during construction.Gas permeability technology is a good way to examine and reflect the crack state and compactness evolution of concrete components.

关 键 词：空心板梁桥 裂缝 气体渗透 围压加卸载 现场测试 脉冲传感器 密实性能 状态评估 

分 类 号：U448.33[建筑科学—桥梁与隧道工程] U445.71[交通运输工程—道路与铁道工程]