钢管自应力混凝土轴压柱的徐变计算模型

为了正确估计钢管自应力混凝土轴压柱的徐变及其对轴压柱长期性能的影响,对钢管自应力混凝土轴压柱的徐变计算模型进行了试验与理论分析.通过试验研究了钢管自应力混凝土轴压柱的长期力学性能,利用龄期调整的有效模量法建立了钢管自应力混凝土轴压柱在长期荷载作用下的徐变分析模型.结果表明:荷载作用一年后的钢管自应力混凝土轴压柱的极限承载力高于没有施加荷载的试件,所建立的徐变计算模型可以较好地模拟钢管自应力混凝土轴压柱的徐变试验结果;与普通混凝土相比,钢管约束下的自应力核心混凝土长期变形很小,但是引起的应力重分布不容忽视;含钢率对钢管自应力混凝土轴压柱长期变形性能的影响较为显著.

Creep computation module of self-stressing concrete-filled steel tube under axial load

To correctly predict the creep and its effect on the long-term mechanical performance of self-stressing concrete-filled steel tube,the creep computation module of the steel tube under axial load was analyzed by theory and tests.A numerical model to analyze the deformation of self-stressing concrete-filled steel tube under long-term loading was established using age-adjusted effective modulus method.It is showed that the ultimate bearing capacity of self-stressing concrete-filled steel tube subjected to the load for one year is higher than that of the sample without load,and the numerical model provided can simulate the creep test results well.Compared with the common concrete,the long-term deformation of self-stressing core concrete restrained by steel tube is very small,but the stress redistribution between steel tube and concrete is correspondingly large.The area of steel tube to concrete core ratio has more remarkable effect on the long-term deformation of self-stressing concrete-filled steel tube than other factors.