钢管自密实自应力混凝土短柱轴压力学性能试验研究

结合自密实混凝土和自应力混凝土的特点，配制出有自密实性的自应力混凝土．将其应用于钢管混凝土内，不仅可以解决钢管混凝土浇注不密实，混凝土干缩、徐变等问题，而且还可以解决自应力混凝土约束不足的问题,试验通过6个钢管自应力自密实混凝土短柱试件研究了钢管约束下自应力混凝土的膨胀性能．分析结果表明，徐变变形和弹性变形占有效自由膨胀变形的2／3左右，这部分变形在计算中不容忽视．膨胀稳定后，初始自应力值能达到3～6MPa,通过18个试件研究了短柱轴压力学性能，试验结果表明：在初始应力的影响下，钢管自应力混凝土的弹性工作阶段比普通钢管混凝土大10％左右，承载力也有5％～20％的提高．

Research on mechanical performance of self-compacting and self-stressing concrete-filled steel tube short column under axial loading

Combining the characteristics of self-compacting concrete with those of self-stressing concrete, self-stressing concrete with self-compacting capability is produced and applied to steel tube. It can not only make the quality of concrete filled in steel tubes obtain the guarantee to solve the problem of drying shrinkage and creep of concrete, but also solve the problem that the concrete is restrained insufficiently. The expansive performance of self-stressing concrete confined by steel tube is researched through 6 short column specimens. Analytical results indicate that elastic deformation and creep account for 2/3 of effective free expansion approximately, and should not be ignored in calculation. After expanding steadily, the self-stress of core concrete can reach 3-6 MPa. The performance of short column under axial loading is researched through 18 specimens. Under the influence of initial stress, the elastic working range of self-stressing concrete-filled steel tube is greater than concrete-filled steel tube about 10%, the loading capacity is improved by 5%-20%.