Influence of silica fume on the interfacial bond between aggregate and matrix in near-surface layer of concrete
Influence of silica fume on the interfacial bond between aggregate and matrix in near-surface layer of concrete
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DOI：
10.1016/j.conbuildmat.2009.01.006
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发表时间：
2009-07
影响因子：
7.4
通讯作者：
D. Xuan;Z. Shui;Shaopeng Wu
中科院分区：
文献类型：
--
作者：
D. Xuan;Z. Shui;Shaopeng Wu
界面过渡区作为混凝土中最薄弱的部位，一直受到人们的关注。本文从宏观和微观两个层面对混凝土近表层骨料与基质的界面粘结进行了研究。通过去除一定的表层砂浆，暴露粗骨料，制备了不同硅灰掺量(水泥质量分数分别为0%、6%、9%和12%)和水泥用量(400和450 kg/m~3)的试件。通过拔出试验和显微硬度测试评价了界面粘结性能。研究发现，近表面区团聚体周围的ITZ不仅受墙体效应和团聚体下微渗水积累的影响，而且还受近表面薄弱区效应的影响。外加硅灰可依次提高混凝土界面粘结强度，减小混凝土近表面薄弱区厚度，改善混凝土近表面层ITZ。
The interfacial transition zone (ITZ) as the weakest position in concrete is always paid much attention. This paper presents the results of an investigation on the interfacial bond between aggregate and matrix in the near surface layer of concrete at the macro- and micro-level. Specimens with different silica fume additions (0%, 6%, 9% and 12% by mass of cement) and cement dosages (400 and 450kg/m3) were prepared by removing certain near-surface mortar and making coarse aggregates exposed. The interfacial bond properties were evaluated by the pull-out test and microhardness test. It was found that ITZs around the near-surface-zone aggregate were influenced not only by the Wall Effect and the accumulation of microbleeding water under aggregate, but also by the near-surface weakness zone effect. The additional silica fume can successively enhance the interfacial bond strength, decrease the thickness of the near-surface weakness zone and improve ITZs in the near-surface layer of concrete.