环氧树脂-混凝土叠合结构的热应力分析

发布时间：2018-07-03 03:08

  本文选题：桥梁工程 + 热应力　； 参考：《公路交通科技》2017年12期

【摘要】：为解决环氧树脂-混凝土叠合结构在温度变化时因两种材料变形不协调而造成结构破坏的问题,进行了环氧树脂-混凝土叠合结构的热应力研究,对结构在环氧树脂固化阶段、养护阶段、后固化阶段和使用阶段进行应力分析,提出各阶段环氧树脂中存在的热应力有收缩应力、固化应力、后固化应力和温度应力,给出了这些应力的计算公式,并进行了有限元计算和试验验证,结果表明:(1)从环氧树脂浇注到混凝土上那一刻开始,就会由于树脂的固化反应、以及温度的变化而在体系内部产生应力,主要包含收缩应力、固化应力、后固化应力、温度应力;(2)较小的弹性模量能有效降低环氧树脂-混凝土叠合结构的固化应力、后固化应力和温度应力,但常温下表现为低弹性模量的环氧树脂在低温时其弹性模量会急剧上升,有时会增加几十倍,大大增加了低温时的温度应力;(3)常温养护时,高温后固化的环氧树脂-混凝土叠合结构的内应力变化比较复杂,因高温后固化会降低环氧树脂的线性热膨胀系数,增加其弹性模量以及热变形温度,同时也会产生固化收缩,最终应力累积的计算需要大量试验数据;(4)环氧树脂最大平均弹性模量为131.9 MPa(20℃至-20℃的平均弹性模量,环氧树脂线胀系数取100×10~(-6)(m·m~(-1))/℃)时,可通过ASTM C884中相容性试验测试。
[Abstract]:In order to solve the problem of structure failure caused by the deformation of two kinds of materials when the temperature change of epoxy resin concrete composite structure, the thermal stress of epoxy resin concrete composite structure was studied, and the structure was cured by epoxy resin. The stress analysis of curing stage, post curing stage and application stage is carried out, and the thermal stress in each stage of epoxy resin is put forward, such as shrinkage stress, solidification stress, post solidification stress and temperature stress, and the calculation formula of these stresses is given. The finite element calculation and test results show that: (1) from the moment of epoxy resin pouring to concrete, the curing reaction of resin and the change of temperature will produce stress in the system, which mainly includes shrinkage stress. Curing stress, post curing stress and temperature stress. (2) the curing stress, post curing stress and temperature stress of epoxy resin concrete composite structure can be effectively reduced by small elastic modulus. At room temperature, however, the elastic modulus of epoxy resin with low modulus of elasticity increases sharply at low temperature, and sometimes increases by dozens of times, which greatly increases the thermal stress at low temperature. (3) when curing at room temperature, The internal stress changes of epoxy resin / concrete composite structure cured after high temperature are more complicated, because curing after high temperature will reduce the linear thermal expansion coefficient of epoxy resin, increase its elastic modulus and thermal deformation temperature, at the same time, it will produce curing shrinkage. (4) when the maximum average elastic modulus of epoxy resin is 131.9 MPA (from 20 鈩，

本文编号：2092124