低温制备硅灰-偏高岭土-矿渣基地聚物砂浆试验及微观研究  

Experimental Investigation and Microstructural Analysis of Low Temperature Prepared Silica Fume⁃Metakaolin⁃Slag Based Geopolymer Mortar

作　　者：吕炎 白二雷[1] 王志航 孟欣 孙慧颖 LYU Yan;BAI Erlei;WANG Zhihang;MENG Xin;SUN Huiying(Aviation Engineering School,Air Force Engineering University,Xi'an 710038,China;Zhongtian Northwest Construction Group Co.,Ltd.,Xi'an 710077,China)

机构地区：[1]空军工程大学航空工程学院,西安710038 [2]中天西北建设集团有限公司,西安710077

出　　处：《材料导报》2023年第S02期210-218,共9页Materials Reports

基　　金：国家自然科学基金(51908548,52278287);国家人民防空办公室立项课题(RF20SC01J-S0);陕西省高校科协青年人才托举计划项目(20200415)。

摘　　要：为提升低温环境下矿渣基地聚物砂浆性能,通过掺加硅灰、偏高岭土实现对矿渣基地聚物砂浆的复合改性,并通过正交试验研究硅灰、偏高岭土、减水剂的掺量以及水玻璃与氢氧化钠溶液质量比对硅灰-偏高岭土-矿渣基地聚物砂浆(SMSGM)力学性能和工作性能的影响,并确定最佳配合比。在此基础上作对比验证试验,探究低(负)温对SMSGM力学性能的影响,并分析了低(负)温养护下地聚物砂浆的微观形貌、红外吸收性质、孔隙结构。结果表明:SMSGM的流动性及强度受水玻璃与氢氧化钠溶液质量比影响最大;正交试验中,硅灰掺量为10%、偏高岭土掺量为20%、减水剂掺量为0.8%、水玻璃与氢氧化钠溶液质量比为0.5是最优配合比,3 d抗压强度可达30.1 MPa;温度降低至-10℃后,SMSGM表面存在大量未参与反应的原材料,水化产物未充分胶结,孔隙量增大,毛细孔数目增多,宏观表现为强度降低,但水化反应释放的大量热可支持SMSGM早期强度的形成,验证了其在寒冷条件下使用的可行性,以期为寒区基础设施快速修复的应用提供理论依据和指导。In order to improve the performance of slag⁃based geopolymer mortar at low temperature environment,the compound modification of slag⁃based geopolymer mortar by using silica fume and metakaolin,and the effect of the dosing of silica fume,metakaolin,water reducing agent and the mass ratio of sodium silicate to sodium hydroxide solution on the mechanical properties and workability of the silica fume⁃metakaolin⁃slag based geopolymer mortar(SMSGM)were investigated by orthogonal tests,and the best matching ratio was determined.On this premise,comparative verification tests were carried out to investigate the impacts of low(negative)temperature on the mechanical properties of SMSGM,as well as the microscopic morphology,infrared absorption properties,and pore structure of the slag⁃based geopolymer mortar at low(negative)temperatures.The results showed that the mass ratio of sodium silicate to sodium hydroxide solution had the greatest influence on the fluidity and strength of SMSGM;in the orthogonal test,the optimal ratio of silica fume with 10%,metakaolin with 20%,water reducing agent with 0.8%and sodium silicate to sodium hydroxide solution with 0.5 mass ratio was used,and the 3 d compressive strength could reach 30.1 MPa;after the temperature is lowered to-10℃,a large amount of raw materials not involved in the reaction exists on the surface of the SMSGM,the hydration products are not fully cemented,the pore volume increases,the number of capillary pores increases,and the macroscopic performance is reduced in strength,but the large amount of heat released from the hydration reaction can support the formation of early mechanical strength of SMSGM,which verifies the feasibility of its use under cold conditions,with a view to providing theoretical basis and guidance for the application of rapid infrastructure rehabilitation in cold regions.

关 键 词：硅灰-偏高岭土-矿渣基地聚物砂浆 低温环境 早期力学性能 正交试验 配合比优化 微观结构 

分 类 号：TU578.1[建筑科学—建筑技术科学]