超大体积承台混凝土温升形变影响因素应用研究  

Influence Factor of Temperature Rise and Deformation for Cushion-Cap Mass Concrete

作　　者：邹建文[1] 徐伟[1] 

机构地区：[1]同济大学建筑工程系,上海200092

出　　处：《结构工程师》2009年第6期133-137,共5页Structural Engineers

基　　金："十一五"国家科技支撑计划项目(2006BAG04B05)

摘　　要：早龄期温度差是引起承台大体积混凝土产生裂缝主要原因之一,在大体积混凝土工程中,混凝土材料选用、配合比设计应以控制温度差、减小绝热温升为目标。分析了组成混凝土各种材料对混凝土水化温度的影响,以此为参考优化配合比。并以长112.75m、宽48.1m、厚13.324m,C35混凝土的哑铃形承台为工程背景,介绍了混凝土的配合比的设计及温控措施,通过对监测结果分析得出结论:降低水泥用量、高掺量掺加粉煤灰、添加外加剂、严格控制水灰比及延长混凝土设计控制龄期等方法有利于延缓和降低水化热,是控制大体积混凝土温度裂缝的有效手段。Temperature difference at early ages is one of the prime reasons causing mass concrete cracking. In construction, the controlling target is to reduce the temperature difference and the strain of dry shrinkage by selecting material and concrete design plan. Analysis of material influence on heat of hydration can be used to design the proportion of mass concrete. Taking background of a practical program of the cushion-cap with dimension of 112.75 m long,48.1 m wide, and 13. 324 m high,the recommendation was proposed for concrete proportion and the measure of controlling temperature in different cushion caps under the same condition. Conclusion about concrete thermal index was educed that retarding and reducing heat of hydration by decreasing cement, mixing into fly ash, mixing additive, controlling ratio of cement and water and postponing concrete age are available means to control heat and cracks in mass concrete.

关 键 词：承台大体积混凝土 温升 材料性能 配合比 温度监测 

分 类 号：U445.559[建筑科学—桥梁与隧道工程]