首页|冻融环境下泡沫混凝土的孔结构与力学性能

冻融环境下泡沫混凝土的孔结构与力学性能

Pore structure and mechanical properties of foam concrete under freeze-thaw environment

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对 4种不同密度的泡沫混凝土试样进行了冻融循环试验,借助X-CT设备扫描了泡沫混凝土的孔隙结构,并使用声发射装置测试了泡沫混凝土单轴压缩过程中的声发射特征.结果表明:泡沫混凝土在单轴压缩过程中的应力-应变关系曲线具有明显的阶段性,单轴压缩过程中的声发射事件主要集中在接触期和陡增期.冻融循环后,泡沫混凝土的孔隙率和平均孔隙直径均增大,孔径分布更离散,孔隙壁厚度不断减小,引起力学性能的下降;冻融循环降低了试样的脆性,使其声发射累计振铃计数曲线更光滑,信号的活跃度随冻融次数的增加而降低;密度为 1 000 kg/m3 的试样在冻融循环 100次后,其大部分孔径在 1 000 µm以下,抗压强度只降低了23.7%,具有良好的抵抗冻融侵蚀的能力.
The freeze-thaw tests of four kinds of foam concrete samples with different density were carried out.The pore structure of foam concrete was scanned with X-CT equipment,and the acoustic emission characteristics of foam concrete during uniaxial compression were tested by acoustic emission device.The results show that obvious stages exist in the process of uniaxial compression test and the acoustic emission events in the process of uniaxial compression are mainly concentrated in the contact period and steep growth period.After freeze-thaw cycles,the porosity and average pore diameter of foam concrete increase,the pore size distribution is more discrete,and the thickness of pore wall decreases,which leads to the decrease of mechanical properties.The freeze-thaw cycle re-duces the brittleness of the samples,and the cumulative ring count curve of acoustic emission is smoother.Besides,the signal activity decreases with the increase of freeze-thaw times.After 100 freeze-thaw cycles,most of the pore size of the sample with 1 000 kg/m3 density is less than 1 000 µm,and the compressive strength is only reduced by 23.7%.It has a good ability to resist freeze-thaw erosion.

foam concretefreeze-thaw cyclesuniaxial compressionacoustic emissionpore structure

高志涵、陈波、陈家林、袁志颖

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河海大学 水利水电学院,南京 210098

河海大学 水文水资源与水利工程科学国家重点实验室,南京 210098

泡沫混凝土 冻融循环 单轴压缩 声发射 孔隙结构

国家自然科学基金面上项目国家自然科学基金重点项目国家重点实验室基本科研业务费

5207904951739003522012272

2024

复合材料学报
北京航空航天大学 中国复合材料学会

复合材料学报

CSTPCD北大核心
影响因子:0.933
ISSN:1000-3851
年,卷(期):2024.41(2)
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