基于微预应力-固结理论的早龄期混凝土高温拉伸徐变试验与模拟

发布时间：2018-06-24 23:28

本文选题：混凝土 + 早龄期拉伸徐变　；参考：《工程力学》2017年03期

【摘要】：研究了早龄期混凝土高温拉伸徐变特性,建立起能够考虑混凝土内部水化热和外界环境温度影响,并且适用于早龄期混凝土拉伸徐变的数值计算方法。采用自行设计的门式徐变加载设备和环境箱控制系统,进行了室温(23℃)和高温(43℃)环境下的混凝土拉伸徐变试验,加载龄期分别为1 d、7 d和28 d。利用徐变试验结果确定模型的计算参数,进而模拟、验证温度因素对于混凝土拉伸徐变的影响。研究结果表明,早龄期混凝土的拉伸徐变对混凝土的加载龄期和温度变化非常敏感,基于微预应力-固结理论建立起考虑温度效应和早龄期特征的数值模型,可以较好地描述不同温度历史下的早龄期混凝土拉伸徐变特征。模型采用应力-应变增量关系进行数值计算,能够为通用有限元软件徐变分析的二次开发提供基础。
[Abstract]:The characteristics of high temperature tensile creep of early age concrete are studied. A numerical method is established which can consider the effects of hydration heat of concrete and ambient temperature, and it is applicable to the tensile creep of early age concrete. The room temperature (23 degrees C) and high temperature (43 C) are carried out by the self designed portal creep loading equipment and the environment box control system. Under the environment, the tensile creep tests of concrete under the environment are 1 D, 7 d and 28 d., respectively, to determine the calculation parameters of the model by the results of creep test, and then simulate the effect of temperature factors on the tensile creep of concrete. The results show that the tensile creep of early age concrete changes very much for the loading age and temperature of concrete. Sensitivity, based on the micro prestress consolidation theory, a numerical model considering the temperature effect and the early age characteristics is established, which can better describe the tensile creep characteristics of early age concrete under different temperatures. The model adopts the stress strain increment relation for numerical calculation, which can be used for the two development of the development of the finite element software creep analysis. For the foundation.
【作者单位】：清华大学土木工程系土木工程安全与耐久教育部重点实验室;
【基金】：国家自然科学基金项目(51578316)
【分类号】：TU528

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