加密硅灰在净浆和混凝土中的作用对比
冯竟竟，于 雷，刘 勇，刘 洋
（山东农业大学水土学院土木系，山东泰安271018）
摘要：为了探讨加密硅灰在净浆和混凝土中的作用效果差异，设置了4种不同的加密硅灰掺量（0%、6%、12%、18%），研究加密硅灰对混凝土抗压强度、净浆抗压强度、孔隙特征和微观形貌的影响。研究结果表明：加密硅灰在净浆硬化浆体中的团簇作用明显，部分硅灰团簇内有明显裂缝，使净浆总孔隙率增大，造成净浆抗压强度降低；加密硅灰在混凝土体系中，由于骨料的磨擦作用，团簇较少，能够相对较好的分散，且硅灰的火山灰反应起到改善界面过渡区的作用，使混凝土抗压强度提高。
关键词：加密硅灰；净浆；混凝土；分散效果
中图分类号：TU528；TU502；TG115.21+5.3 文献标识码：A doi:10.3969/j.issn.1000-6281.2015.06.006
Comparison of the roles of densified silica fume in paste and concrete
FENG Jing-jing，YU Lei，LIU Yong，LIU Yang
(Department of Civil Engineering, Shandong Agriculture University, Taian Shandong271018, China)
Abstract：This study investigates the differences of the roles of densified silica fume in paste and concrete. Four silica fume adding amount were set: 0%，6%，12% and18%. The influences of densified silica fume on the compressive strength of concrete and paste, and the pore structure and micro-morphology of paste were measured.The results show that there are many densified silica fume clusters in the hardened paste and there are even large cracks in some clusters, which increases the total porosity and reduces thecompressive strength of hardened paste. The attrition of aggregates during mixing makes densified silica fume better dispersed, and the pozzolanic reaction of silica fume improves the interfacial transition zone, which lead to the increase of the compressive strength of concrete.
Keywords：densified silica fume；paste；concrete；dispersion effect
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