摘要
超硫酸盐水泥是一种环境友好的胶凝材料,但存在早期强度低的缺陷。为探索超硫酸盐水泥早期强度的提高途径,研究了硝酸钙掺量对超硫酸盐水泥强度的影响,并通过离子浓度、X射线衍射仪(XRD)、孔结构、扫描电镜(SEM)等分析方法对硝酸钙影响水泥强度的机制进行了探讨。结果表明,硝酸钙掺量从0提高到2.0%,超硫酸盐水泥3 d强度提高尤为明显,且其后期强度仍有较大提高。其中,3 d龄期最佳掺量为1.5%,7 d、28 d和90 d龄期最佳掺量为1.0%。硝酸钙的增强作用主要可归因于其能提高水泥的水化速率,降低水化体系的碱度,促进钙矾石由细针状向短柱状转变,并降低水泥的孔隙率。掺入硝酸钙是提高超硫酸盐水泥强度的有效途径。
As an environmentally friendly cemental material,supersulfate cement has the defect of low strength in early stage.In order to explore a way to improve its early strength,the effect of calcium nitrate content on the strength was studied,and the mechanism was analyzed by methods of ion concentration,XRD,pore structure and SEM.The results show that the strength of supersulfate cement is significantly improved with calcium nitrate content from 0 to 2.0%at 3 d age,and the strength is still greatly improved later.The optimum content of calcium nitrate is 1.5%at 3 d age,and it is 1.0%at the age of 7 d,28 d and 90 d.It is the main enhancement mechanism that calcium nitrate improves the hydration rate of cement,reduces the alkalinity of hydration system,promotes the transformation of ettringite from acicular to columnar,and reduces the porosity of cement harden paste.Adding an appropriate amount of calcium nitrate is an effective way to improve the strength of supersulfate cement.
作者
陈宇
严金生
章迪
季军荣
詹早良
陈胡星
CHEN Yu;YAN Jinsheng;ZHANG Di;JI Junrong;ZHAN Zaoliang;CHEN Huxing(School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China;Chongzuo South Cement Co.,Ltd.,Chongzuo 532201,China;Zhejiang Dingfeng Technology Co.,Ltd.,Shaoxing 312028,China)
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2023年第4期576-582,共7页
Journal of Materials Science and Engineering
基金
四川省科技计划资助项目(2023YFSY0019)。
关键词
超硫酸盐水泥
硝酸钙
强度
Supersulfate cement
Calcium nitrate
Strength
