新型速凝剂水化机理及工程特性试验研究  

Experimental Study on Hydration Mechanism and Engineering Characteristics of New Accelerator

作　　者：赵伟[1,2] 雷升祥[1,2,3] 肖清华[1,2] 刘纪峰 ZHAO Wei;LEI Shengxiang;XIAO Qinghua;LIU Jifeng(Key laboratory Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Construction Corporation Limited,Beijing 100855,China;Sanming University,Sanming 365004,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]西南交通大学土木工程学院,成都610031 [3]中国铁建股份有限公司,北京100855 [4]三明学院,福建三明365004

出　　处：《铁道标准设计》2019年第10期142-147,共6页Railway Standard Design

基　　金：国家重点研发计划(2018YFC0808702);湖南省科技厅2017年度省重点研发计划(2017SK2393);工程材料与结构加固福建省高校重点实验室开放基金(B170001-1)

摘　　要：喷射混凝土是矿山法修建隧道的基本措施,速凝剂作为喷射混凝土必需的外加剂,对工程质量和经济效益具有重要影响。结合正在建设的某高地应力软岩隧道,分析碱性(Na^+·AlO^-2溶液)和非碱性(Al^3+·SO^2-4溶液)速凝剂的促凝机理,并开展新型碱性液体速凝剂的室内试验和现场湿喷试验,得出如下结论:(1)碱性速凝剂和非碱性速凝剂的促凝机理都是利用活性Al^3+的水化反应;(2)碱性速凝剂产生粉尘主要是由于超量的Na^+中断了水泥的水化反应,非碱性速凝剂是由于SO42+中断了水泥的水化反应;(3)新型碱性速凝剂最大的特点是降低了Na^+/Al^3+的摩尔比(1.19:1),具有无毒无味、掺量少、落浆回弹少、早强且后期强度损失少等优点,是一种理想的喷射混凝土用速凝剂。Shotcrete is a basic means of tunnel construction by mining method. As a necessary admixture of shotcrete, accelerator has important influence on the quality and economic benefits of the project. In this paper, the mechanism of alkaline and alkali-free accelerator are analyzed. Furthermore, the indoor and in-situ experiments of the new alkaline liquid accelerator are carried out in the construction of a high geo-stress soft rock tunnel. The following conclusions could be drawn:(1)Both the mechanism of alkaline and alkali-free accelerator are taking the advantage of Al^3+ hydration reaction;(2)The dust produced by the alkaline accelerator is resulted from the excessive interruption of hydration reaction of cement Na+;while the dust generated by the alkaline-free accelerator is resulted from the interruption of the hydration reaction of cement SO4^2-.(3)The main advantage of the new liquid accelerator is the reduction of molar ratio Na^+/Al^3+(1.19:1), it is characterized by nontoxic and tasteless, low dosage, shorter setting time, less rebound droplet and less strength loss in later period. Conclusively, this novel admixture is an ideal accelerator for shotcrete in soft rock tunnel.

关 键 词：隧道工程 喷射混凝土 速凝剂 强度 回弹量 

分 类 号：TQ172.46[化学工程—水泥工业]