标准养护下CaO-粉煤灰地聚物制备及微观研究  

Study on Preparation and Microstructure of Fly Ash-Based Geopolymer at Standard Temperature Curing

作　　者：毛明杰[1] 马明晓 ShuIng Doh 杨秋宁[1] Mao Mingjie;Ma Mingxiao;ShuIng Doh;Yang Qiuning(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan,Ningxia 750021;College of Engineering,Universiti Malaysia Pahang,Gambang,Kuantan,Pahang,Malaysia 26300)

机构地区：[1]宁夏大学土木与水利工程学院,宁夏银川750021 [2]马来西亚彭亨大学工程学院,马来西亚彭亨州关丹26300

出　　处：《非金属矿》2020年第4期28-32,共5页Non-Metallic Mines

基　　金：国家自然科学基金(51568055);宁夏回族自治区对外科技合作专项资助项目(2018BFH03002)。

摘　　要：在标准养护下,向粉煤灰中掺入适量CaO制备粉煤灰基地质聚合物。结果表明,加入CaO在早龄期会使抗压强度出现下降,养护7d后抗压强度随CaO掺量增加出现先增大后减小的趋势,最优nCa/nSi为0.18。粉煤灰玻璃球中的硅铝相经历了解聚-聚合的过程,体系中水化硅酸钙(C-S-H)凝胶和地质聚合物凝胶(N-A-S-H/C-A-S-H)共存,水化产物为无定形结构,无新的结晶相生成。CaO过量(nCa/nSi>0.18)时,Ca(OH)2及CO32-的存在会对材料抗压强度产生不利影响。CaO is incorporated into fly ash to prepare fly ash-based geopolymer with standard curing. The results show that the addition of CaO decreases the compressive strength in the early age, but compressive strength increases first and then decreases with the increase of CaO content after curing for 7 days. The optimal molar ratio of Ca to Si is 0.18. The silica-aluminum phase in the fly ash microspheres undergoes a process of depolymerization-polymerization. The C-S-H gel and geopolymer gel(N-A-S-H/C-A-S-H) coexist in the system. The hydration product is amorphous structure, and no new crystalline phase is generated. When CaO is excessive(nCa/nSi>0.18), Ca(OH)2 and CO32- adversely affect the compressive strength.

关 键 词：粉煤灰 地质聚合物 微观结构 地质聚合物凝胶 

分 类 号：TU526[建筑科学—建筑技术科学]