C_(4)A_(3)S-CS对硅酸盐水泥体积稳定性与力学性能的影响  

ffect of C_(4)A_(3)S-CS on Volumetric Stability and Mechanical Properties of Portland Cement

作　　者：裴天蕊 齐冬有 邹德麟 赵卫丽 汪智勇 郝禄禄 王亚丽[1] 张钰 刘洪印 PEI Tianrui;QI Dongyou;ZOU Delin;Zhao Weili;WANG Zhiyong;HAO Lulu;WANG Yali;ZHANG Yu;LIU Hongyin(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Technicalsupervision&Research Center for China Building Materials,Beijing 100124,China;Cnnp Guodian Zhangzhou Energy Co.,Ltd.,Zhangzhou 353300,Fujian,China;China National Building Materials Exhibition&Trade Center,Beijing 100080,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]建筑材料工业技术监督研究中心,北京100024 [3]中核国电漳州能源有限公司,福建漳州363300 [4]国家建筑材料展贸中心,北京100080

出　　处：《硅酸盐学报》2024年第5期1520-1531,共12页Journal of The Chinese Ceramic Society

基　　金：北京市科技计划项目(Z221100007522002)。

摘　　要：针对预制构件存在早期强度发展不足,后期体积稳定性差的缺点,以无水硫铝酸钙(C_(4)A_(3)S-CS)和硬石膏(CS)作为调控胶凝材料,针对C_(4)A_(3)S-CS对硅酸盐水泥体积稳定性和力学性能的影响机理进行了探讨,对制备体积稳定的早强硅酸盐水泥基胶凝材料具有一定的指导意义。先用自由膨胀率与抗压强度分析了C_(4)A_(3)S-CS-PC水泥浆体的体积及力学性能变化规律,再用X射线衍射仪、热分析仪、压汞仪和扫描电镜探究了该体系膨胀及水化机理。结果表明:C_(4)A_(3)S-CS能改善硅酸盐水泥的体积稳定性,提高其早期强度,加速水泥的水化进程。当C_(4)A_(3)S-CS含量为10%、CS/C_(4)A_(3)摩尔比为11时,12h钙矾石(AFt)含量可达5.61%,28 d含量为8.51%。C_(4)A_(3)S-CS和CS的水化作用会消耗硅酸盐矿物水化产生的Ca(OH)2。细针棒状的AFt生长在水泥硬化浆体的表面及孔隙中,与水化硅酸钙(C-S-H)凝胶在水泥浆体中相互胶结,使得孔径明显细化,最可几孔径减小至12 nm,水泥浆体的28 d总孔隙率下降至17.24%,结构更加致密,利于硅酸盐水泥体积稳定性发展。Introduction With the rapid development of assembled buildings,the low-carbon and high-efficient production of precast concrete components becomes a hotspot for the industry.Portland cement(PC),as one of the most important cementitious materials for the preparation of precast components,has the disadvantages of insufficient early strength development and late volumetric shrinkage.To realize the volume stability of non-steam-cured precast components,expansion agents are often introduced into Portland cement.Sulphoaluminate cement(CSA)with a large amount of Ye'elimite and gypsum is often used to improve the early strength and volumetric stability of PC.Different types of CSA have different expansion capacities due to the different contents of Ye'elimite and gypsum,affecting the composition of the hydration products with the saturation of ettringite.In this paper,the mechanical properties and volumetric stability of the specimens were investigated via varying the relative contents of C_(4)A_(3)S and CS in Portland cement(i.e.,CS/C_(4)A_(3)S molar ratio and C_(4)A_(3)S-CS content).The hydration process,phases composition,and the microstructure of system were characterized to analyze the effect of C_(4)A_(3)S-CS on the hydration of Portland cement.Methods Portland cement clinker(Tangshan Jidong Cement Sanyou Co.,Ltd.,China),and anhydrite(Tangshan Polar Bear Building Materials Co.,China)were used as raw materials.CaCO_(3),Al_(2)O_(3),and CaSO_(4)-2H_(2)O mixed in a molar ratio of 3:3:1 were heat-treated in a high-temperature muffle furnace for 2 h to obtain the C_(4)A_(3)S mineral.Four different CS/C_(4)A_(3)S molar ratios of M,2,5,8 and 11 were designed,while five C_(4)A_(3)S-CS content levels of 5%,10%,15%,20%and 25%were set up in a total of 20 sets of crossover experiments.The 10%-M2 represents the content of this sample of C_(4)A_(3)S-CS in Portland cement clinker is 10%at the CS/CA,S molar ratio M of 2.The water-cement ratio was 0.35,and the paste was molded as a net paste test block with the sizes of 20 mm×20 mm

关 键 词：硅酸盐水泥 无水硫铝酸钙 硬石膏 水化 体积稳定性 

分 类 号：TQ172.72[化学工程—水泥工业]