Effect of flexural loading on degradation progress of recycled aggregate concrete subjected to sulfate attack and wetting-drying cycles; [弯曲荷载对再生混凝土在硫酸盐侵蚀和干湿循环下劣化进程的影响]

被引：4

作者：

Zhao Y. ^{[1
,2
]}

Gao J. ^{[1
,2
]}

Qi B. ^{[1
,2
]}

Liu C. ^{[1
,2
]}

机构：

[1] School of Materials Science and Engineering, Southeast University, Nanjing

[2] Jiangsu Key Laboratory of Construction Materials, Southeast University, Nanjing

来源：

Journal of Southeast University (English Edition) | 2019年 / 35卷 / 01期

基金：

中国国家自然科学基金;

关键词：

Degradation; Flexural loading; Recycled aggregate concrete; Sulfate attack; Wetting-drying cycles;

D O I：

10.3969/j.issn.1003-7985.2019.01.012

中图分类号：

学科分类号：

摘要：

The degradation progress of recycled aggregate concrete (RAC) subjected to sulfate attack under wetting-drying cycles and flexural loading is studied. Three different stress ratios (0, 0.3 and 0.5) were applied in this test. The variations of relative dynamic elastic modulus Erd and water-soluble SO42- contents in RAC were used to evaluate degradation progress. The changes in mineral products and microstructures of interior concrete were investigated by means of X-ray diffraction (XRD), the environmental scanning electron microscope (ESEM) and X-ray computed tomography (X-CT). The results indicate that flexural loading accelerates the degradation of RAC under sulfate attack and wetting-drying cycles by expediting the transmission of SO42- into interior concrete. Furthermore, the accelerated effect of flexural loading is more obvious with the increase of stress ratio, that is because higher stress ratios can accelerate the extension of microcracks and generate more channels for the transmission of SO42-. Also, more expansive products (gypsum and ettringite) are generated by the reaction of Ca(OH)2 with SO42-, which can further accelerate the degradation of RAC. © 2019, Editorial Department of Journal of Southeast University. All right reserved.

引用

页码：83 / 88

页数：5