超细水泥-硅灰二元低pH注浆材料特性研究  

Characteristics of Binary Low-pH Grouting Material Containing Superfine Cement and Silica Fume

作　　者：赵卫全[1] 任增增 张金接[1] 李勇辉 张翔宇[2] ZHAO Weiquan;REN Zengzeng;ZHANG Jinjie;LI Yonghui;ZHANG Xiangyu(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;State Key Laboratory for Geomechanics&Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,徐州221116

出　　处：《硅酸盐通报》2023年第4期1156-1165,共10页Bulletin of the Chinese Ceramic Society

基　　金：核设施退役治理专项资助科研项目(科工二司[2020]194号);中国水利水电科学研究院重点专项(EM0145B022021)。

摘　　要：采用简化磨碎溶出法测试了硅灰(SF)掺量为30%~50%(质量分数,下同)、水胶比为1.4的超细水泥(SC)注浆材料结石体在不同龄期的pH值,探讨SF掺量、SiO_(2)含量和C-S-H凝胶理论钙硅摩尔比对注浆材料pH值的影响,并测试了60%SC+40%SF低pH注浆材料的流变性能和力学性能,同时利用SEM、XRD、TG表征手段分析了结石体的水化产物和微观结构。结果表明,当SF掺量大于40%、SiO_(2)含量大于50%、C-S-H凝胶钙硅摩尔比小于0.8时,结石体pH值小于11.00。萘系减水剂(SP)能显著降低浆液的马氏漏斗黏度,SP适宜掺量为1.6%。宾汉姆模型能够很好地描述浆液流变性能。水胶比的提高对结石体抗压强度有不利影响,因此水胶比不宜超过1.6。由于SF具有火山灰效应和稀释效应,养护180 d后结石体内不存在Ca(OH)_(2),其主要水化产物为低钙硅比的C-S-H凝胶和钙矾石。The pH value of superfine cement(SC)grouting material stone body with silica fume(SF)content of 30%~50%(mass fraction,the same below)and water-binder ratio of 1.4 at different ages was measured by simplified ex-situ leaching method.Meanwhile,the effects of SF content,SiO_(2) content and theoretical Ca/Si molar ratio of C-S-H gel on grouting material pH value were investigated.The rheological properties and mechanical properties of 60%SC+40%SF low-pH grouting material were examined.In addition,SEM,XRD and TG were used to examine the hydration products and microstructure of stone body.The results show that when SF content is more than 40%,SiO_(2) content is more than 50%and Ca/Si molar ratio of C-S-H gel is less than 0.8,the pH value of stone body is less than 11.00.The naphthalene superplasticizer(SP)greatly reduces the marsh funnel viscosity of slurry,and the appropriate content of SP is 1.6%.The Bingham model provides a satisfactory description of the rheological properties of slurry.The increase of water-binder ratio has adverse effect on the compressive strength of stone body,so the water-binder ratio should not exceed 1.6.Due to the pozzolanic effect and dilution effect of SF,there is no Ca(OH)_(2) in stone body after curing for 180 d,and its principal hydration products are C-S-H gel with a low Ca/Si molar ratio and ettringite.

关 键 词：低pH注浆材料 超细水泥 硅灰 钙硅摩尔比 孔溶液 结石体 

分 类 号：TU172.1[建筑科学—建筑理论]