青藏铁路西格二线混凝土冻融试验研究

Study on concrete frost-thawing test of Qinghai-Tibet Railway Xige No.2 line

由于工期的要求,青藏铁路西格增建二线必须进行冬期施工。根据工程状况,分析了混凝土受冻的破坏机理,针对施工环境及对混凝土设计强度和要求,进行了大量冻融试验分析,对引气剂、水胶比、砂率、粉煤灰掺量等原材料与混凝土含气量的关系及其混凝土搅拌温度与静停时间等对混凝土性能的影响进行了分析与技术论证,确保了该线冬期混凝土施工顺利进行。

Added Xige No.2 line of Qinghai-Tibet Railway has to be constructed in winter due to time limit for the project. Analysis is made on failure mechanism of concrete caused by freezing according to the engineering conditions and a great deal of frost-thawing test analysis is made on the construction circumstances, design strength and demand to the concrete, analysis and technical proof are also made on relationship of raw material content such as air entraining agent, W/B （water-binder） ratio, sand percentage and fly ash with concrete air content as well as influence of concrete mixing temperature and delaying curing time on concrete performance that ensure the concrete construction of this line in winter be succeeded.