混凝土收缩徐变的长期效应对混合体系竖向变形差的影响

对于钢框架-钢筋混凝土核心筒混合体系，混凝土的收缩和徐变将直接影响混凝土筒体的缩短并通过连系梁影响钢柱的缩短，从而影响柱筒竖向变形差.本文采用由时间因子控制的.同时考虑施工过程及混凝土收缩徐变效应的位移法递推方程研究了上述问题.分析表明，混凝土收缩徐变的长期效应非常显著，湿度的减小将加剧这种影响.考虑截至结构主体施工完毕3年的混凝土收缩徐变时，结构顶部筒体的累积缩短值将超过钢柱的累积缩短值；钢柱轴力的增加一般超过10%；结构顶部楼层筒体的轴力将变为拉力；部分钢梁弯矩将发生反向.

The Long Term Effects of Concrete Shrinkage and Creep on Vertical Differential Shortening of Hybrid Structures

In steel frame-reinforced concrete corewall structures, concrete shrinkage and creep directly affect the shortening of corewalls and then influence the shortening of columns through beams, and have a significant impact on the vertical differential shortening. Controlled by time parameter, the displacement method recurrence equation, which takes into account the construction procedure and the concrete shrinkage and creep effect, was used to provide numerical computation for the above problem. The studies show that the long-term concrete shrinkage and creep have great effect on the vertical differential shortening, and that the decreased environment humidity enhances these effects. When considering the concrete shrinkage and creep up to 3 years after the completion of the main structure, the cumulative shortening of concrete corewalls exceeds that of steel columns in top storeys. The axial compressive forces of columns usually increase by more than 10%, and the axial compressive forces of corewalls in top storeys become tensional. The bending directions of some beams reverse to affect beam design.