冻融与碳化耦合作用下节段梁胶接缝耐久性研究  

Durability of Segmental Beam Epoxied Joints Under Coupling Action of Freeze-Thaw Cycle and Carbonization

作　　者：张京京 石庆波 周方南 王海良 郭晓宇 黄欣[1] ZHANG Jingjing;SHI Qingbo;ZHOU Fangnan;WANG Hailiang;GUO Xiaoyu;HUANG Xin(China Railway 18th Bureau Group Corporation Limited,Tianjin 300222,China;School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China)

机构地区：[1]中铁十八局集团有限公司,天津300222 [2]天津城建大学土木工程学院,天津300384

出　　处：《铁道建筑技术》2023年第8期6-10,16,共6页Railway Construction Technology

基　　金：天津市轨道交通重大专项(18ZXGDGX00050)。

摘　　要：节段梁拼装采用胶接缝技术优势显著,但受碳化侵蚀影响较大,且在冻融耦合作用下耐久性不明。以环氧树脂胶接缝为研究对象,创新提出倒角胶接缝工艺,并与不处理、打磨、凿毛等界面形式进行对比,开展单一碳化试验和冻融-碳化耦合试验。结果表明:在单一碳化和冻融-碳化耦合作用下,胶接缝耐久性均表现为倒角>凿毛>打磨>不处理,倒角胶接缝耐久性最优;XRD扫描分析验证了倒角胶接缝工艺比凿毛胶接缝晚25个冻融循环出现碳化现象;冻融循环对胶接缝碳化侵蚀具有促进作用,单一碳化作用和冻融-碳化耦合作用下,4种胶接缝处混凝土碳化深度值随时间变化过程均符合二项式,呈非线性关系;凿毛对混凝土有一定损伤,导致环氧树脂胶粘结面积增大,因此凿毛胶接缝耐久性优于打磨胶接缝,且冻融会加剧该损伤,即冻融-碳化耦合作用下凿毛胶接缝处混凝土碳化深度相对单一碳化作用更大。The use of epoxied joint technology for segmental beam assembly is significant,but it is greatly influenced by carbonization and its durability under freeze-thaw coupling is unknown.Taking the epoxied joint as the research object,the chamfering joint technology is innovatively put forward,and compared with direct joint,polish joint,gouging joint and other form,the single carbonization test and freeze-thaw-carbonization coupling test are carried out.The results show that,under single carbonization and freeze-thaw-carbonization coupling,the durability of epoxied joint is manifested as chamfering joint higher than gouging joint,followed by polish joint,and the last is direct joint,so the durability of chamfering joint is the best.XRD analysis shows that the chamfering glue joint is carbonized 25 freeze-thaw cycles later than gouging joint.The freeze-thaw cycle can promote the carbonization erosion of chamfering joints.The variation of concrete carbonation depth with time for the four epoxied joints under the coupling action of single carbonation and freeze-thaw-carbonation conforms to binomial,showing a nonlinear relationship.Gouging damages the concrete to a certain extent,resulting in an increase in epoxy area,so the durability of the gouging joint is superior to that of the polish joint.In addition,the damage will be aggravated by freeze-thaw,and the concrete carbonation depth of freeze-thaw-carbonation at the gouging joint is greater than that of single carbonation.

关 键 词：冻融-碳化 耦合作用 胶接缝 耐久性 试验 

分 类 号：TU528[建筑科学—建筑技术科学] U444[建筑科学—桥梁与隧道工程]