- 目录
- 建筑石膏与胶凝材料
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海水拌合养护对粉煤灰-水泥胶凝浆体微结构形成演变规律的影响
作者：付浩兵1，吴业君1，卢飞1，刘丞尉1，汪迪2，丁庆军2
（1.保利长大工程有限公司，广东 广州 510620；
2武汉理工大学 硅酸盐工程中心国家重点实验室，湖北 武汉 430070）
摘要：通过XRD、SEM、29Si和27Al NMR等测试技术，研究了海水拌合与养护粉煤灰-水泥胶凝浆体微结构的形成演变机理。结果表明：海水拌合与养护会固化硅酸盐水泥中C3A形成的Al3+，产生Friedel's盐与AFt，降低浆体中C-S-H的Al[4]/Si，提高其聚合程度和分子链长（MCL），且变化幅度随水化龄期的延长而增大；随养护龄期延长，C-A-S-H中的Al向AFt、AFm和Friedel's盐中转移。粉煤灰的掺入可削弱海水拌合与养护对胶凝浆体的脱铝作用；随养护龄期延长，C-S-H凝胶硅氧链的聚合度和MCL增大，Al[4]/Si先增大后减小；粉煤灰和C-A-S-H中的Al向AFt、AFm以及Friedel's盐中迁移。
关键词：海水拌合；粉煤灰-水泥胶凝浆体；微结构；C-（A）-S-H凝胶；29Si NMR；27Al NMR
中图分类号：TU528 文献标识码：A 文章编号：1001-702X（2022）07-0092-06
Effect of seawater mixing and curing on the formation and evolution of the microstructure of fly ash-cement paste
FU Haobing1，WU Yejun1，LU Fei1，LIU Chengwei1，WANG Di2，DING Qingjun2
（1.Poly Changda Engineering Co. Ltd.，Guangzhou 510620，China；
2.State Key Laboratory of Silicate Materials for Architectures，Wuhan University of Technology，Wuhan 430070，China）
Abstract：The formation and evolution mechanism of the microstructure of the seawater mixing and curing cementitious paste was studied by XRD，SEM，29Si and 27Al NMR and etc. The results showed that the seawater mixing and curing would solidify the Al3+ formed by C3A in Portland cement，produce Friedel's salt and AFt，reduce the Al[4]/Si of CSH in the slurry，increase the degree of polymerization and molecular chain length（MCL），and the range of change increases with the extension of hydration age. As the curing age increases，the Al in C-A-S-H transfers to AFt，AFm and Friedel's salt; the incorporation of fly ash can weaken the dealumination effect of seawater mixing and curing on the cementitious slurry. With the extension of the curing age，the degree of polymerization and MCL of the silicon-oxygen chain of the C-S-H gel increase，and Al[4]/Si first increases and then decreases. Al in fly ash and CASH migrate to AFt，AFm and Friedel's salt.
Key words：seawater mixing，fly ash-cement paste，microstructure，C-（A）-S-H gel，29Si NMR，27Al NMR