硅灰对混凝土开裂敏感性的影响  

Influence of Silica Fume on Cracking Sensitivity of Concrete

作　　者：刘可心[1,2] 李进辉[1,2] 屠柳青[1,2] 张国志[1,2] 孙砚红[1,2] 

机构地区：[1]中交武汉港湾工程设计研究院有限公司,湖北武汉430071 [2]长大桥梁建设施工技术交通行业重点实验室,湖北武汉430071

出　　处：《施工技术》2009年第S2期368-371,共4页Construction Technology

摘　　要：采用温度应力试验机研究了不同水胶比、不同硅灰掺量及硅灰与粉煤灰混掺对混凝土开裂敏感性的影响,并同纯水泥及常用海工混凝土进行比较。试验结果表明:对于掺硅灰混凝土的开裂敏感性,每一硅灰掺量都存在一个合适的水胶比范围,过高或者过低都会增加开裂敏感性,且硅灰掺量越高相应合适的水胶比越大;同水胶比条件下,随着硅灰掺量的提高,开裂敏感性增加,但在合适的水胶比条件下,与基准混凝土相比,8%以下掺量并不增加混凝土的开裂敏感性;在硅灰混凝土中掺入适量的优质粉煤灰能够降低混凝土的开裂敏感性;与矿粉混掺粉煤灰的海工混凝土相比,硅灰混掺粉煤灰混凝土抗开裂性能与之相当,同时保持早强的优势。The influence factors,such as water-binder ratio, mixing amount of silica fume and addition of silica fume and fly ash,on cracking sensitivity of reinforced concrete are studied by using temperature-stress test machine.Moreover,the cracking sensitivity of concrete with silica fume is also studied and analyzed by comparing with pure cement concrete and marine concrete with fly ash and slag powder.The results indicate that: in terms of cracking sensitivity of concrete,each silica fume content has a suitable water-binder ratio range.Moreover,the higher the amount of silica fume is,the bigger the corresponding appropriate water-binder ratio.In addition,cracking sensitivity increases with the content of silica fume under the condition of the same water-binder ratio,but it is not higher than that of the corresponding control concrete unless the mixing amount is below 8% and the water-binder ratio is appropriate.And cracking sensitivity decreases and gets improved when fly ash adds in silica fume concrete.Furthermore,compared with common marine concrete with fly ash and slag powder,cracking sensitivity of concrete with silica fume and fly ash is equivalent to that of the marine concrete with slag powder and fly ash under the condition of proper water-binder ratio,but it has the advantages of high early strength.

关 键 词：混凝土 硅灰 温度应力 开裂敏感性 影响 

分 类 号：TU528.042[建筑科学—建筑技术科学]