非晶态C_(12)A_(7)基水泥速凝剂速凝机理研究  

Investigation on Accelerating Mechanism of Amorphous C_(12)A_(7)-Based Cement Accelerator

作　　者：何建能 张江涛 郝爽 马强 王健 王奕仁 He Jianneng;Zhang Jiangtao;Hao Shuang;Ma Qiang;Wang Jian;Wang Yiren(Transportation Bureau of Huining County,Baiyin,Gansu 730799;China Building Materials Academy,CNBM Zhongyan Technology Co.,Ltd.,Beijing 100024;Beijing Municipal Road and Bridge Technology Development Co.,Ltd.,Beijing 100037;School of Ecological Environment and Architectural Engineering,Dongguan Institute of Technology,Dongguan,Guangdong 523429)

机构地区：[1]甘肃省会宁县交通运输局,甘肃白银730799 [2]中国建筑材料科学研究总院,中建材中岩科技有限公司,北京100024 [3]北京市政路桥科技发展有限公司,北京100037 [4]东莞理工学院生态环境与建筑工程学院,广东东莞523429

出　　处：《非金属矿》2023年第4期36-40,共5页Non-Metallic Mines

基　　金：中国建筑材料科学研究总院-*非金属材料创新中心应用示范类项目(2022SFP2-1)。

摘　　要：本研究以非晶态铝酸钙矿物C_(12)A_(7)(Ca12Al14O33)为主要成分,复配CaSO_(4)·2H_(2)O、Na2SO_(4)、NaAlO_(2)制备新型粉体速凝剂,并采用X射线衍射(XRD)、热重-差热(TG-DTA)和扫描电镜(SEM)等微观表征方法分析了掺加速凝剂的水泥硬化浆体中水化产物的组成和微观形貌。XRD结果表明,掺加速凝剂的样品水化10 min后发现了明显的钙矾石(AFt)和Ca(OH)_(2)特征峰。TG-DTA分析结果表明,掺加速凝剂的水化样品中水化产物的热失质量和结合水量均高于对应的空白样品,随着水化龄期的增长,趋势越来越明显。掺入6%速凝剂的水化28 d样品水化产物中的结合水量为11.18%,高于同龄期空白样品中水化产物的结合水含量(8.26%)。SEM分析结果表明,掺入6%速凝剂的水化28 d样品中生成了更多的针状钙矾石。速凝剂中各组分对水泥具有协同促进作用,促使硬化浆体中生成更多的水化产物,不同形貌的产物相互胶结在一起使硬化浆体更加密实。In this paper,a new kind of accelerator was prepared using amorphous calcium aluminate mineral C_(12)A_(7) as the main component,mixing with CaSO_(4)·2H_(2)O,Na2SO_(4),NaAlO_(2) and the composition and microstructure of the hydration products in the presence of accelerator were analyzed by XRD,TG-DTA,SEM.XRD results showed that the peaks of AFt and Ca(OH)_(2) were found after 10 min of hydration of the sample mixed with accelerator.Moreover,the weight loss in TG-DTA results and bound water content of the hydration products in the hydration samples mixed with accelerators were higher than that of blank samples and the trend became more obvious with the increase of hydration.The amount of bound water in 28 d hydration product of sample mixed with 6%accelerator was 11.18%,which was higher than the crystal water content(8.26%)of the hydration product in the blank sample of the same age.SEM results showed that more needle-like ettringite was formed in 28 d hydration sample mixed with 6%accelerator.The synergistic effect of components in accelerator on cement promoted the formation of more hydration products in the hardened pastes,and the different shaped products were cemented together to make the hardened pastes denser.

关 键 词：非晶态C_(12)A_(7) 速凝剂 凝结时间 速凝机理 

分 类 号：TQ172[化学工程—水泥工业] TU528.042[化学工程—硅酸盐工业]