页岩陶粒轻骨料混凝土高温后蠕变特性
作者:
作者单位:

1.安徽理工大学 土木建筑学院,安徽 淮南 232001;2.安徽理工大学 土木工程博士后流动站,安徽 淮南 232001

作者简介:

刘雨姗(1997—),女,安徽亳州人,安徽理工大学博士生. E-mail:liuyushan1997@126.com;

通讯作者:

庞建勇(1964—),男,河北保定人,安徽理工大学教授,博士生导师,博士. E-mail:pangjyong@163.com

中图分类号:

TU528.2

基金项目:

中国博士后科学基金面上资助项目(2020M681974);安徽省高等学校自然科学研究项目(KJ2020A0297);安徽理工大学校级资助项目(QN2019115);安徽理工大学研究生创新基金(2020CX1004)


Creep Behavior of Shale Ceramsite Lightweight Aggregate Concrete Exposed to High Temperature
Author:
Affiliation:

1.School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan 232001, China;2.Postdoctoral Station of Civil Engineering, Anhui University of Science and Technology, Huainan 232001, China

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    摘要:

    为探究高温对页岩陶粒轻骨料混凝土(SCLAC)蠕变特性的影响,进行了室温至800 ℃后SCLAC单轴压缩试验、分级压缩蠕变试验和扫描电镜(SEM)试验,分析了SCLAC质量损失、抗压强度损失、蠕变特性及微观结构特征.结果表明:随温度升高,SCLAC的内部微观结构变得疏松,质量、抗压强度逐渐降低,800 ℃后质量损失率为9.54%,抗压强度损失率为63.88%;随温度升高和应力水平增加,蠕变应变和蠕变速率增大,蠕变历时和蠕变破坏临界应力水平减小;温度高于600 ℃时蠕变应变明显增大,在相同应力水平下,与室温相比600 ℃后的蠕变应变增加了82.76%.基于试验结果对Burgers蠕变模型参数进行辨识,所得理论曲线与减速蠕变阶段和等速蠕变阶段的试验数据吻合较好.

    Abstract:

    To study the influence of high temperature on the creep behavior of shale ceramsite lightweight aggregate concrete(SCLAC), uniaxial compression test, multistage creep test and scanning electron microscope(SEM) test of SCLAC exposed from room temperature to 800 ℃ were carried out. The loss of mass and compressive strength, creep behavior and microstructure characteristics of SCLAC were analyzed. The results show a decrease in the mass and compressive strength and the internal microstructure becomes more loose, as the temperature rises. After 800 ℃, the loss ratio of mass and compressive strength is 9.54% and 63.88%, respectively. With higher target temperature and higher stress level, the creep strain and creep rate increase, while the creep failure threshold stress and creep duration reduce, significantly. Furthermore, the creep strain of SCLAC exhibits a considerable increase above 600 ℃ and the creep strain under the same loading ratio at 600 ℃ increases by 82.76%, compared to the creep at room temperature. Based on the test results, the Burgers creep model agrees well with the creep test data at the primary creep stage and stable creep stage.

    表 3 SCLAC配合比Table 3 Mix proportions of SCLAC kg/m3
    表 6 Burgers蠕变模型参数Table 6 Simulated parameters of Burgers creep model (λ=0.4)
    表 2 页岩陶粒的基本性能Table 2 Basic performance of shale ceramsite
    表 1 粉煤灰的化学组成Table 1 Chemical composition of fly ash
    图1 高温后SCLAC质量及抗压强度损失情况Fig.1 Loss of mass and compressive strength of SCLAC exposed to high temperature
    图2 高温后SCLAC分级压缩蠕变曲线Fig.2 Multistage compression creep curves of SCLAC exposed to high temperature
    图3 高温后SCLAC应力水平与瞬时应变关系Fig.3 Relationship between stress level and transient strain of SCLAC exposed to high temperature
    图4 20、800 ℃后SCLAC在不同应力水平下的蠕变速率Fig.4 Creep stain rate of SCLAC under different stress levels exposed to 20,800 ℃
    图5 高温后试件φ值随应力水平的变化趋势Fig.5 Variation of φ value of specimens with stress level
    图6 Burgers 蠕变模型Fig.6 Creep model of Burgers
    图7 不同温度后SCLAC在第1级应力水平下蠕变试验数据和Burgers蠕变模型曲线Fig.7 Creep strain curves of SCLAC after exposure to different temperatures for experimental data and Burgers creep model under the first stress level (λ = 0.4)
    图8 高温后水泥基体的SEM图Fig.8 SEM micrographs of cement matrix exposed to high temperature
    图9 高温后页岩陶粒与水泥基体界面过渡区SEM图Fig.9 SEM micrographs of interfacial transition zone between shale ceramsite and cement matrix exposed to high temperature
    图10 20、800 ℃后页岩陶粒的微观形貌Fig.10 Micro-structures of shale ceramsite exposed to 20,800 ℃
    表 5 SCLAC破坏时的应力水平及蠕变历时Table 5 Failure stress level and creep durations for SCLAC
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引用本文

刘雨姗,庞建勇,姚韦靖.页岩陶粒轻骨料混凝土高温后蠕变特性[J].建筑材料学报,2021,24(5):1096-1104

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  • 收稿日期:2020-07-03
  • 最后修改日期:2020-11-09
  • 录用日期:2020-11-09
  • 在线发布日期: 2021-12-15
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