防水混凝土在隧道二次衬砌裂缝填补中的应用  

Application of waterproof concrete in crack filling of tunnel secondary lining

作　　者：宋佳宁 曾庆伟[1] 王安东[1] Song Jianing;Zeng Qingwei;Wang Andong(Shaanxi Railway Institute,Weinan 714000,Shaanxi,China)

机构地区：[1]陕西铁路工程职业技术学院,陕西渭南714000

出　　处：《中国胶粘剂》2023年第5期40-45,共6页China Adhesives

基　　金：陕西省教育厅自然科学基金项目(19JK0200)。

摘　　要：将水泥、粉煤灰和外加防水剂等原料依照一定比例配制,制作出防水混凝土样品。测试了防水混凝土在隧道二次衬砌裂缝填补中的应用效果,研究了防水混凝土在隧道二次衬砌裂缝填补中的抗渗性、抗裂性等多种性能,同时观察干燥前后隧道二次衬砌裂缝填补中建筑材料的微观结构。研究结果表明:在隧道二次衬砌裂缝填补的应用中,粉煤灰有助于混凝土增加抗渗性,超量取代比例在15%至25%之间较适合;当高水胶比时,掺入适当型号的防水剂可提高抗渗性能;当低水胶比时,混凝土无需添加防水剂;在粉煤灰取代比例相同的条件下,超量取代的混凝土具有较好的抗氯离子扩散性;粉煤灰能够避免混凝土早期开裂,且添加不同粉煤灰比例的混凝土具有开裂时间较晚、裂缝宽度较窄的特性;添加粉煤灰的混凝土微观结构呈现紧密的细针棒状钙矾石晶体,经过干燥试验后,混凝土具有较强的抗拉强度。Waterproof concrete samples were prepared by mixing cement,fly ash and waterproof agent in a certain ratio.The application effect of waterproof concrete in crack filling of tunnel secondary lining was tested,and various properties such as impermeability and crack resistance of waterproof concrete in crack filling of tunnel secondary lining were studied.At the same time,the microstructure of building materials in crack filling of tunnel secondary lining before and after drying was observed.The research results showed that in the application of crack filling of tunnel secondary lining,fly ash helped to increase the impermeability of concrete,and an excess replacement ratio between 15%and 25%was suitable.When the water cement ratio was high,adding an appropriate type of waterproof agent could improve the impermeability performance.When the water cement ratio was low,there was no need to add waterproof agent to the concrete.Under the same replacement ratio of fly ash,concrete with excessive replacement had good resistance to chloride ion diffusion.Fly ash could avoid early cracking of concrete,and concrete with different fly ash ratios had the characteristics of later cracking time and narrower crack width.The microstructure of the concrete added with fly ash exhibited dense fine needle bar ettringite crystals,the concrete had strong tensile strength after the drying test.

关 键 词：粉煤灰 混凝土 防水剂 裂缝填补 水压力抗渗性 二次衬砌 抗裂性能 

分 类 号：TU528[建筑科学—建筑技术科学]