【摘要】 分析了钢管混凝土的收缩与膨胀特性，认为冷缩和徐变收缩是造成膨胀钢管混凝土收缩的主要原因，混凝土是按照弹性回伸机理进行补偿收缩的。针对膨胀钢管混凝土的特点，开发出储能延迟膨胀剂，采用该种膨胀剂改变了钢管混凝土传统补偿收缩模式，使钢管混凝土按照延迟膨胀模式进行，减少了自应力的损失，有效利用了膨胀能，大大提高了钢管混凝土的承载力。更多还原

【Abstract】 The characteristics of concrete filled steel tube(CFST)’s volume contraction and expansion are analyzed in this paper.The contracts with cold and creep are the main reasons of the CFST volume contraction.The shrinkage-compensating of CFST is carried out according to the elastic recovery mechanism.In accordance with the properties of CFST,we manufactured the stored energy delayed expansive agent which changed the traditional shrinkage-compensating mechanism of CFST into delayed expansion mechanism.Using this kind of expansive agent,the prestress loss is remarkably reduced,the expansive energy is utilized effectively and the load capacity of CFST is increased obviously.更多还原