碳纤维布加固混凝土矩形墩柱温度自应力探讨

Discussion on the Temperature Self-Restrained Stress of Rectangular Section Concrete Pier Strengthened by Carbon Fiber Sheet

基于平截面假定和自平衡力系条件,对碳纤维布(CFS)加固的任意形状横截面混凝土构件,建立日照辐射或骤然降温引起的温度自约束变形求解方程。推导CFS加固混凝土矩形墩柱在均匀变化、线性变化和指数变化温度梯度下的温度自应力解析式。与未加固混凝土矩形墩柱温度自应力解析式进行对比分析,结果表明,即使在均匀和线性变化温度梯度下,CFS加固矩形墩柱也会产生温度自应力;在指数变化温度梯度下,CFS中产生可观的温度自应力。所推导的自约束变形求解方程和温度自应力解析式具有一般性,适用于CFS加固混凝土构件和未加固混凝土构件。

By using the assumption of plane cross section and the condition of self-equilibrating force system, the equation about temperature self-restrained deformation due to solar radiation or abrupt temperature drop is established for the concrete member with arbitrary cross-section strengthened by carbon fiber sheet （CFS）. Analytic formula of temperature self-restrained stress is derived for rectangular section concrete pier under three kinds of temperature gradient modes： homogeneous distribution, linear distribution and exponent distribution. Compared with original rectangular-section concrete pier, still there is temperature self-restrained stress caused by homogeneous or linear temperature gradient in the whole section, and considerable temperature self-restrained stress caused by exponent temperature gradient in CFS. The equation and the analytic formula represented in this paper is general, which can be applied to concrete member whether strengthened by CFS or not strengthened by CFS.