功能外加剂对隧道二次衬砌拱顶充填砂浆性能的影响  

Effect of Functional Admixtures on the Performances of Mortars Filling behind Tunnel Vault Secondary Lining

作　　者：彭磊 何文敏[1,2] 惠海涛 李炳良[1,2] 高妮 PENG Lei;HE Wenmin;HUI Haitao;LI Bingliang;GAO Ni(Shaanxi Engineering Laboratory of High Performance Concrete,Weinan 714099;School of Surveying and Testing,Shaanxi Railway Institute,Weinan 714099;Shaanxi Zhuoxin Engineering Testing Co.,Ltd.of China Railway First Group Co.,Ltd.,Xi′an 710199)

机构地区：[1]陕西省高性能混凝土工程实验室,渭南714099 [2]陕西铁路工程职业技术学院测绘与检测学院,渭南714099 [3]中铁一局集团陕西卓信工程检测有限公司,西安710199

出　　处：《现代隧道技术》2021年第5期244-251,共8页Modern Tunnelling Technology

基　　金：陕西省渭南市科技计划项目(2020ZDYF-JCYJ-232);陕西铁路工程职业技术学院中青年科技创新人才(KJRC201806);陕西铁路工程职业技术学院高性能混凝土科技创新团队(KJTD201802)。

摘　　要：为了解决隧道二次衬砌拱顶脱空等问题,基于铁路隧道二次衬砌充填砂浆基本性能要求,在OPC∶SAC=0.65∶0.35,胶砂比=0.55∶0.45,水料比为0.18,粉煤灰掺量为10%的基础上,通过流动度、泌水率、强度、膨胀性和干缩性等方面,开展功能外加剂对充填砂浆性能影响的研究。结果表明:酒石酸掺量为0.3%,碳酸锂掺量为0.2%,塑性膨胀剂掺量为0.06%,消泡剂掺量为0.15%,保水增稠剂掺量为0.12%,可制备出工作自密实、不泌水、不离析、早期强度高、后期强度高、微膨胀的充填砂浆;充填砂浆与衬砌混凝土结合性试验、施工现场雷达无损检测和拱顶钻芯结果表明,充填砂浆与隧道二次衬砌混凝土结合性好,可减少隧道二次衬砌背后脱空情况,避免了衬砌充填材料与二次衬砌混凝土"两张皮"现象。As for the vault voids and other issues of tunnel secondary lining,based on the basic performance requirements for filling mortars of secondary lining of railway tunnels,and under mixture formula of OPC∶SAC=0.65∶0.35,cement∶sand=0.55∶0.45,water:aggregate=0.18 and 10%fly ash admixture,this paper studies the effect of functional admixtures on the performance of mortars in terms of the fluidity,bleeding rate,strength,expansibility and dry shrinkage,etc.The results show that:under the mixing dosages of 0.3%tartaric acid,0.2%lithium carbonate,0.06%plastic expander,0.15%defoamer and 0.12%water-retaining thickener,the filling mortar can be prepared with properties of self-compacting,no bleeding,no segregation,high early and long-term strength,and micro expansion;through the bonding test of filling mortar and lining concrete,field radar nondestructive testing and vault core drilling,the results show that there is a good bonding capability between the filling mortars and the tunnel secondary lining,which could mitigate voids behind tunnel secondary lining and avoid the separation between filling materials and secondary lining concrete.

关 键 词：带模注浆 隧道二次衬砌充填砂浆 功能外加剂 OPC-SAC混合水泥体系 

分 类 号：U455.91[建筑科学—桥梁与隧道工程]