钢管自密实轻骨料混凝土变形性能试验研究

Deformation Performance of Steel Tube Self-Compacting Lightweight Aggregate Concrete

采用堆积密度分别为500 kg/m^(3)、800 kg/m^(3)的页岩陶粒和堆积密度为1600 kg/m_(3)的普通碎石作为粗骨料配制自密实轻骨料混凝土和普通混凝土,并成型了钢管轻骨料混凝土与钢管普通混凝土,对比研究了二者的收缩应变、轴压应力-应变变化规律和温度-应变变化规律。结果表明:随着粗骨料堆积密度的降低,同配比轻骨料混凝土的密度、强度和弹性模量均逐渐降低;相同龄期时,钢管轻骨料混凝土及其核心轻骨料混凝土的收缩应变均小于钢管普通混凝土及其核心混凝土的收缩应变,钢管与核心轻骨料混凝土的密贴性更好;钢管轻骨料混凝土的轴压应力-应变变化规律与钢管普通混凝土的基本相同,与钢管普通混凝土相比,钢管轻骨料混凝土的弹性模量有所降低,但比非钢管约束状态下轻骨料混凝土弹性模量的降低幅值有所减小;钢管轻骨料混凝土与钢管普通混凝土的温度-应变相当,均为4.0με/℃左右。

Using shale ceramsite with bulk density of 500 kg/m_(3) and 800 kg/m_(3) and gravel with bulk density of 1600 kg/m_(3) as coarse aggregates to prepare self-compacting lightweight aggregate concrete and ordinary concrete,forming steel tube lightweight aggregate concrete and ordinary concrete-filled steel tube.Compared with ordinary concrete-filled steel tube,the shrinkage strain,axial compression stress-strain change rule and temperature-strain change rule of the two are contrasted.The results show that as the bulk density of coarse aggregate decreases,the density,strength and elastic modulus of the same proportion of lightweight aggregate concrete gradually decrease.At the same age,the shrinkage strain of steel tube lightweight aggregate concrete is smaller than that of steel tube ordinary concrete,and the shrinkage strain of core lightweight aggregate concrete is also smaller than that of core ordinary concrete,better adhesion between steel tube and core lightweight aggregate concrete.The axial compression stress-strain change law of lightweight aggregate concrete-filled steel tube is basically the same as that of ordinary concrete-filled steel tube.Compared with ordinary steel tube concrete,the elastic modulus of steel tube lightweight aggregate concrete is reduced,but it is smaller than the reduction amplitude of lightweight aggregate concrete under non-steel tube confinement state.The temperature-strain of lightweight aggregate steel tube concrete and ordinary steel tube concrete are equivalent,both are about 4.0με/℃.