钢管拱自密实混凝土的配制与应用

Preparation and Application of Self-compacting Concrete Filled with Steel Pipe Arch

根据钢管拱桥的连续泵送顶升施工工艺与现场施工条件需求,提出了钢管拱自密实混凝土的性能要求及合适的性能评价方法.通过混凝土配合比基本参数优化、外加剂复掺、矿物掺和料选用等配制技术,试验配制出初始坍落度大于240 mm,坍落扩展度大于650 mm,扩展时间T50为5~15 s,4 h坍落度零损失,常压泌水率为0,强度等级达到C60以上的收缩补偿钢管拱自密实混凝土,并在工程中成功应用.

According to the demands of on-site construction conditions and construction technology of continuous pumping lift-up for steel pipe arch bridge,property requirements and suitable evaluation methods of self-compacting concrete（SCC） filled with steel pipe arch were proposed.By using the preparation techniques including optimization of basic parameters of concrete mix proportion,admixture composition and mineral admixture addition,self-compacting concrete filled with steel pipe arch was prepared with the properties such as initial slump more than 240 mm,slump flow above 650 mm,T_（50） between 5 s and 15 s,no slump loss within 4 h,no bleeding,strength grade above C60 and shrinkage-compensating.It can be applied in the bridge project successfully.