缓凝型水泥浆液配合比优化及锚孔浆岩界面特性影响研究  

Optimization of mix ratio of slow setting cement slurry and influence of slurry rock interface characteristics of anchor hole

作　　者：武朝光 陈治亚 李梓焜[1] 张学民 刘进[1] 陈靖 WU Chaoguang;CHEN Zhiya;LI Zikun;ZHANG Xuemin;LIU Jin;CHEN Jing(School of Civil Engineering,Central South University,Changsha 410075,China;School of Traffic and Transportation Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学交通运输工程学院,湖南长沙410075

出　　处：《铁道科学与工程学报》2024年第5期1954-1965,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51978671)。

摘　　要：针对预应力锚杆后张法施工中自由段浆液流动性和缓凝效果差的工程难题,提出使用标准型聚羧酸减水剂作为掺加剂以实现水泥浆液缓凝并提高其工作性能,探究其对锚孔浆岩界面特性的影响。采用室内试验、SEM电镜扫描等手段,结合Matlab多目标优化等方法,对掺加减水剂的缓凝型水泥浆液的锚固性能及配合比优化展开研究,得出适用于预应力锚杆自由段的注浆材料及其最优配合比,并与现行规范推荐配合比进行锚孔横断面结石特性对比试验。研究结果表明:1)随着水灰比增大,水泥浆液的流动度和凝结时间增大,体积结石率和抗压强度减小;随着减水剂掺量的增大,水泥浆液的流动度和凝结时间增大,体积结石率减小,减水剂对浆液抗压强度影响较小;2)未掺加减水剂时,浆液结石体致密性随着水灰比的增大而降低,掺加减水剂使得浆液结石体表面局部存在相对较大尺度的孔或孔隙,对宏观结石体强度有一定影响;3)通过Matlab多目标优化方法推荐了缓凝型水泥浆液最优配合比为水灰比0.3,减水剂掺量1.85%,相关性能参数符合规范要求,且流动度与抗压强度较规范推荐配合比分别提升了72.3%和107%;4)浸水围岩会弱化浆岩界面的抗剪强度,因此在锚杆灌浆过程中保证横断面结石率有利于提高浆岩界面的抗剪强度,本文提出的最优配合比浆液抗剪强度优于规范推荐配合比浆液。In view of the engineering problems such as poor slurry flow and retarding effect in the free section during post-tensioning of prestressed anchor bolt,standard polycarboxylic acid water reducing agent was proposed to slow down cement slurry and improve its performance.Its influence on the slurry rock interface characteristics of anchor hole was explored.Laboratory tests,SEM electron microscanning and other means,combined with Matlab multi-objective optimization methods,were used to study the anchoring performance and mix optimization of slow setting cement slurry mixed with water reducing agent.The grouting material suitable for the free section of prestressed anchor bolt and its optimal mix ratio were obtained.The cross-sectional stone characteristics of anchor holes were tested with the mix ratio recommended by current norms.The results are shown as follows.(1)With the increase of water-cement ratio,the fluidity and setting time of cement slurry increase,and the volume stone rate and compressive strength decrease.With the increase of water-reducing agent content,the fluidity and setting time of cement slurry increase,the volume stone rate decreases,and the waterreducing agent has no significant effect on the compressive strength of the slurry.(2)Without water-reducing agent,the density of slurry stone body decreases with the increase of water-cement ratio,and the addition of water-reducing agent causes relatively large pores or pores on the local surface of slurry stone body,which has a certain influence on the macroscopic stone strength.(3)Through Matlab multi-objective optimization method,the optimal mix ratio of slow-setting cement slurry is recommended to be 0.3 water-cement ratio and 1.85%waterreducing agent content.The relevant performance parameters meet the requirements of the specification,and the mobility and compressive strength are increased by 72.3%and 107%respectively compared with the recommended mix ratio of the specification.And(4)Immersed surrounding rock will weaken the shear strength of the

关 键 词：预应力锚杆 自由段注浆材料 聚羧酸减水剂 工作性能 配合比多目标优化 

分 类 号：TU528.572[建筑科学—建筑技术科学]