早龄期张拉对预应力混凝土梁徐变的影响  

Research on the influence of pre-stress tensioning on creep of concrete beams at early ages

作　　者：熊维[1,2] 丁红岩[2] 

机构地区：[1]天津城建大学土木工程学院,天津300384 [2]天津大学土木工程学院,天津300072

出　　处：《建筑结构》2014年第14期24-27,20,共5页Building Structure

摘　　要：采取室内试验与有限元分析相结合的手段,研究早龄期张拉预应力是否可以降低混凝土梁的徐变值。室内试验部分以实际工程为依托,制作了4根1∶6的缩尺试件。设计了两种不同的预应力张拉方案,通过比较不同方案中预应力筋的预应力损失、梁的挠度、梁截面混凝土的应变、梁截面曲率等方面的试验数值,可以看出在早龄期进行张拉的两次张拉方式对于降低混凝土徐变是最有效的。又利用有限元计算了两种张拉方案中预应力混凝土梁的竖向变形,验证了试验的准确性,并再次证实了早龄期张拉的施工方法可以明显地降低预应力混凝土梁的徐变值。In order to study whether pre-stress tensioning at early ages may reduce the creep value of concrete beams, indoor test and finite element analysis were combined to carry out the research. Indoor test mainly relies on practical engineering project, four 1：6 micro test specimens were made. Besides, different pre-stress tensioning schemes were designed for the test specimens. By comparing the prestress loss of pre-stress reinforcement, the deflection of beams, the deformation of beams section concrete, the curvature of beams section and other values in these test schemes, it may be discovered that, the two tensioning modes among tensioning operations at early ages are the most effective approaches to reduce the creep value of concrete. On this basis, finite element analysis was applied to calculate the vertical deformation of concrete beams in the two tensioning schemes, which proved the validity of the test conclusion. It is demonstrated that tensioning at early ages may significantly reduce the creep value of pre-stress concrete beams.

关 键 词：早龄期 预应力梁 徐变 试验 有限元分析 

分 类 号：TU757.1[建筑科学—建筑技术科学]