Microcracking and chloride permeability of concrete under uniaxial compression
Microcracking and chloride permeability of concrete under uniaxial compression
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DOI：
10.1016/s0958-9465(00)00029-9
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发表时间：
2000-10-01
影响因子：
10.5
通讯作者：
Sirivivatnanon, V
中科院分区：
文献类型：
--
作者：
Lim, CC;Gowripalan, N;Sirivivatnanon, V
在以前的研究中的微裂纹和快速氯离子渗透性测试，微裂纹量化的总裂纹长度。这是通过检查压缩试验后的混凝土切片进行的。在进行氯化物渗透性试验之前，未尝试在压缩试验期间消除微裂纹。在本研究中，混凝土圆柱在单轴加载。压缩在极限强度的30%和95%之间。采用一种非破坏性的微裂纹评价方法，研究了混凝土圆柱体在受压过程中的渐进微裂纹。在压缩试验后，对从同一圆柱体上切下的试样进行快速氯化物渗透性试验（RCPT）（ASTM C1202）。总裂纹长度也确定从相同的试样与所观察到的微裂纹行为，通过非破坏性测试评估进行比较。当混凝土处于荷载作用下和完全卸载时，微裂纹的特征在比裂纹面积方面是不同的。混凝土的氯离子渗透性（卸载后）似乎受到称为临界应力的一定应力水平的影响。当混凝土试件中的临界应力超过时，测得相对较大的氯离子渗透性。当试样中的临界应力未被超过时，尽管微裂纹大量增加，但渗透率的增加是微不足道的。(C)2000爱思唯尔科技有限公司版权所有。
In the previous studies on microcracks and rapid chloride permeability tests, microcracks were quantified in terms of total crack length. This was carried out by examining concrete slices after compression tests. No attempts have been made to characterise the microcracks during the compression test prior to the chloride permeability test. In the present study, concrete cylinders were loaded under uniaxial. compression between 30% and 95% of the ultimate strength. A non-destructive method of microcrack evaluation was used to study the progressive microcracking in concrete cylinders during compression tests. After the compression test, a rapid chloride permeability test (RCPT) (ASTM C1202) was carried out on a specimen cut from the same cylinder. The total crack length was also determined from the same specimen to compare with the observed microcracking behaviour, assessed by the non-destructive testing. The characteristics of the microcracks in terms of the specific crack area are different when a concrete is under a load and when it is completely unloaded. The chloride permeability of a concrete (after it was unloaded) appears to be influenced by the occurrence of a certain stress level known as the critical stress. When the critical stress is exceeded in a concrete specimen, a comparatively large chloride permeability was measured. Where the critical stress in a specimen is not exceeded, the increase in the permeability is marginal in spite of the large increase in microcracks. (C) 2000 Elsevier Science Ltd. All rights reserved.