作　　者： ; ; ; ;

机构地区： 武汉大学水利水电学院水资源与水电工程科学国家重点实验室

出　　处： 《硅酸盐学报》 2010年第11期2212-2216,共5页

摘　　要： 利用高分辨固体核磁共振仪结合去卷积技术,定量分析了粉煤灰水泥浆体中水泥和粉煤灰的水化程度以及C-S-H凝胶中硅氧-铝氧链平均长度,同时研究了粉煤灰火山灰反应对C-S-H结构的影响。结果表明:水化3 d时,系统中约47%的水泥和14%的粉煤灰参与了水化反应,C-S-H平均链长为3.2;水化120d时,水泥和粉煤灰的水化程度分别为89%和33%,C-S-H平均链长约为3.8,远大于纯水泥浆体中C-S-H的平均链长(为2.7)。水化3 d时粉煤灰玻璃相结构中的Si—O—Si,Si—O—和Al—Al共价键断裂,形成了单体硅酸根和单体铝酸根,这些单体结构桥连体系中的二聚体单元进而提高了C-S-H平均链长。粉煤灰掺入并不会因为C-S-H聚合度提高以及ACL增加就能促进粉煤灰水泥浆体强度。 The hydration degree and average chain length（ACL） of SiO_4 and/or AlO_4 tetrahedra in calcium silicate hydrate（C-S-H） for fly ash-cement（FC） paste were quantitatively analyzed with high resolution solid-state ^（29）Si magic angle spinning nuclear magnetic resonance spectroscopy d deconvolution technique.The effect of pozzolanic reaction of fly ash（FA） on the C-S-H structure was also investigated.The experimental results indicate that the cement of 47%and the FA of 14%can react in the paste in the presence of FA of 30%in mass and the ACL of C-S-H was 3.2 at 3 d.At 120 d,the cement of 89%and the FA of 33%could react,and the ACL of C-S-H was 3.8,which was higher than that in the plain cement paste（ACL was 2.7）.After the covalent bonds of Si-O-Si,Si-O-Al and Al-O-Al in the structure of FA were broken at 3 d,monosilicate Si-OH and Al-OH groups formed,leading to a polymerization of C-S-H dimers and an increase in ACL of C-S-H.Although the addition of FA increased the polymerization of C-S-H and the ACL value,the mechanical strength of hardened FC paste could not be improved.

关 键 词： 核磁共振 水化硅酸钙 水化程度 链长 二聚体

领　　域： [化学工程] [化学工程]