高温后混凝土初始压实阶段应力-应变关系

硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (11): 3627-3633.

高温后混凝土初始压实阶段应力-应变关系

王磊¹, 赵燕茹^2,3, 郝松⁴

1.内蒙古工业大学理学院,呼和浩特 010051;
2.内蒙古工业大学土木工程学院,呼和浩特 010051;
3.内蒙古自治区土木工程结构与力学重点实验室,呼和浩特 010051;
4.海南三亚湾新城开发有限公司,三亚 572000

收稿日期:2021-04-28 修回日期:2021-06-07 出版日期:2021-11-15 发布日期:2021-12-08
通讯作者: 赵燕茹,博士,教授。E-mail:zhaoyanru710523@126.com
作者简介:王磊(1989—), 男, 博士研究生。主要从事混凝土高温力学性能方向的研究。E-mail:191722515@qq.com
基金资助:
国家自然科学基金(11762015,11362013);内蒙古自治区博士研究生科研创新资助项目(B20191133Z)

Stress-Strain Relationship of Concrete after High Temperature in Initial Compaction Stage

WANG Lei¹, ZHAO Yanru^2,3, HAO Song⁴

1. School of Science, Inner Mongolia University of Technology, Hohhot 010051, China;
2. School of Civil Engineering, Inner Mongolia University of Technology, Hohhot 010051, China;
3. Inner Mongolia Key Laboratory of Civil Engineering Structure and Mechanics, Hohhot 010051, China;
4. Hainan Sanya Bay New Town Development Co., Ltd., Sanya 572000, China

Received:2021-04-28 Revised:2021-06-07 Online:2021-11-15 Published:2021-12-08

摘要/Abstract

摘要： 本文对经历5种温度(20 ℃、200 ℃、400 ℃、600 ℃和800 ℃)后的混凝土进行了单轴压缩试验。通过定义压实系数φ和相对密实度Φ两个指标,评价了高温后混凝土的密实程度,探讨了混凝土初始压实阶段随温度的变化规律。同时采用统一形式的分段函数建立了考虑初始压实阶段的高温后混凝土应力-应变全曲线方程。结果表明,当温度为200 ℃和400 ℃时,混凝土峰值应力和弹性模量小幅下降,基体密实度较高,应力-应变曲线的初始压实阶段几乎可以忽略,整个压缩损伤过程呈脆性特征。当温度为600 ℃和800 ℃时,峰值应力和弹性模量大幅减小,峰值应变迅速增加,基体密实程度迅速下降,应力-应变曲线具有明显的初始压实阶段,并且整个压缩损伤过程呈延性特征。本文建立的应力-应变全曲线方程具有拟合度高且参数较少的优势。

关键词: 混凝土, 高温, 单轴压缩, 应力-应变关系, 初始压实阶段

Abstract: Uniaxial compression tests were carried out on concrete after five temperatures (20 ℃, 200 ℃, 400 ℃, 600 ℃ and 800 ℃). The compaction coefficient φ and relative compactness Φ were defined to evaluate the compaction degree of concrete after high temperature. The variation law of initial compaction stage of concrete with temperature was discussed. A unified piecewise function was used to establish the full stress-strain curve equation of concrete after high temperature considering the initial compaction stage. The results show that when the temperature is 200 ℃ and 400 ℃, the peak stress and elastic modulus of concrete decrease slightly. The concrete has a high degree of compaction, and the initial compaction stage of the stress-strain curve is not obvious and can be ignored. The whole compression damage process is brittle. When the temperature is 600 ℃ and 800 ℃, the peak stress and elastic modulus decrease greatly, and the peak strain increases rapidly. The compaction degree of concrete decreases rapidly. The stress-strain curve has an obvious initial compaction stage. The whole compression damage process is ductile. The stress-strain full curve equation established in this paper has the advantages of high fitting degree and relatively few parameters.

Key words: concrete, high temperature, uniaxial compression, stress-strain relationship, initial compaction stage

中图分类号:

TU528.1

王磊, 赵燕茹, 郝松. 高温后混凝土初始压实阶段应力-应变关系[J]. 硅酸盐通报, 2021, 40(11): 3627-3633.

WANG Lei, ZHAO Yanru, HAO Song. Stress-Strain Relationship of Concrete after High Temperature in Initial Compaction Stage[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(11): 3627-3633.

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