钢管拱桥混凝土配合比设计与施工

Design and Construction of Concrete Mixture Ratio for Steel Tube Arch Bridge

西藏昌都澜沧江大桥为大跨度、薄壁钢管混凝土拱桥,其钢管混凝土施工采用泵送顶升法,施工难度大,对混凝土性能要求高。经混凝土配合比设计与优化,制备出满足设计要求的C50微膨胀钢管混凝土,并进行混凝土的拌合物性能、物理力学性能及微观结构分析研究,结果表明,所配制的混凝土不离析、不泌水,坍落度23 cm,混凝土拌和物3 h后的坍落度不小于18 cm,混凝土具有早强、高弹性模量和补偿收缩等性能,完全满足西藏昌都澜沧江大桥钢管混凝土拱桥的工程设计及施工要求。

The Qamdo Lancang river bridge of Tibet is big span, thin-walled concrete-filled steel tube arch bridge. The concrete filled steel tube uses pumping jack-up construction method, which is difficult in construction and has high performance requirements of concrete. Through concrete mixture ratio design and optimization, C50 micro expansive concrete filled steel tube is prepared to meet the design requirements, and the mixture performance physical and mechanical properties and microstructure analysis of concrete are studied. The results show that the mixed concrete has no segregation and no bleeding, 23 cm slump. The slump of concrete mixing content after 3 h is no less than 18 cm. Concrete has high early strength, elastic modulus and shrinkage compensation, fully meeting the engineering design and construction requirements of the bridge.