截面形状对早龄期混凝土构件时变变形的影响研究  

Influence of cross-section shape on time-dependent deformation of early-age concrete members

作　　者：杜成成 邹笃建[1] 刘铁军[1] 滕军[1] 

机构地区：[1]哈尔滨工业大学深圳研究生院,广东深圳518055

出　　处：《建筑结构学报》2016年第10期169-174,共6页Journal of Building Structures

基　　金：国家自然科学基金优秀青年科学基金项目(51422804);国家自然科学基金青年科学基金项目(51308322)

摘　　要：在有效厚度相同的前提下设计了两种不同截面形状的混凝土试件,测量了为期181 d的收缩与徐变变形,研究了截面形状对早龄期混凝土时变变形的影响。试验结果表明:现行规范中所使用的有效厚度并不能全面阐释构件的截面形状和尺寸对混凝土时变变形的影响。在相同有效厚度条件下,相对于方形截面柱,薄板的早期时变变形发展速度快,后期当混凝土内部的水分与外界环境达到平衡以后,截面形状对时变变形的影响变弱,长期来看在相同应力比条件下不同截面形状混凝土试件的时变变形基本一致。由此可知,在高层建筑结构施工过程中需重视截面形状对其竖向变形差的影响。An experimental study to examine the validity of this assumption was presented. Two groups of concrete specimens with two different cross-section shapes were cast under the premise of the same effective thickness. The shrinkage and creep deformation was monitored during a period of 181 days. Experimental results show that effective thickness employed in current prediction models can not totally represent the size and shape effect on time-dependent deformation. For early age concrete under the condition of the same effective thickness, the time-dependent deformation of plate type components has higher development speed relative to the square column type components. In the later period,when there is a moisture balance between the internal concrete and the outside environment,the influence of the cross-section shape on the time-dependent deformation abates. At last,under the condition of the same stress ratio,the time-dependent deformation of concrete specimens with different cross-section shapes is almost identical. Therefore,emphasis should be laid on the influence of cross-section shape on vertical deformation difference in the construction process of high-rise buildings.

关 键 词：混凝土构件 截面形状 竖向变形差 时变变形 徐变 收缩 

分 类 号：TU528.1[建筑科学—建筑技术科学]