预应力混凝土组合梁徐变应力重分布

Redistribution of Creep Stress in Prestressed Concrete Build-up Beam

预应力混凝土组合梁中,先、后浇注的混凝土的龄期和应力水平不同,两部分的徐变变形相互制约,将导致应力重分布,如何计算此效应,一直是一个空白。基于平截面变形假定和线性徐变理论,建立了预应力混凝土组合梁徐变应力重分布的计算理论和公式,供设计参考。最后以预应力混凝土组合T梁为例,分析了徐变应力重分布效应。

Owing to the differences between the ages and stress levels of the prepoured and postpoured concrete in the prestressed concrete buildup beam, the creep deformation of the two parts of the concrete will restrain each other and will cause an effect of redistribution of creep stress, and the ways of how to calculate such effect remains a blank up to this date. In this paper, based on the assumptions of plane surface deformation and theory of linear creep, the calculation theory and formulations for the redistribution of the creep stress in the buildup beam are established and are provided for designers for reference. In addition, the effect of the creep stress redistribution is analyzed by way of example of a prestressed concrete buildup Tbeam.