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Experimental Study on Effects of Aging Time on Dry Shrinkage Cracking of Lime Soils

Authors :
Jianwei Yue
Ying Chen
Zhenxian Luo
Siyuan Wang
Huicong Su
Huijie Gao
Yuan Li
Peng Li
Can Ma
Source :
Materials; Volume 15; Issue 16; Pages: 5785
Publication Year :
2022
Publisher :
Multidisciplinary Digital Publishing Institute, 2022.

Abstract

The effect of aging on the internal mechanism of the dry shrinkage cracking of lime soil was studied from the perspective of macroscopic cracking phenomenon and microscopic composition change, and the reasonable aging time of lime soil was determined. Large numbers of cracks often occur in buildings constructed using lime soil, which impacts sustainable development and building environmental protection. This study explored the influence of aging time on the mechanical properties and shrinkage cracking of lime soil. The influence of aging time was evaluated using a triaxial compression test; using the dry–wet cycle, sieving, pH, and other tests, the influence of aging time on volume crack rate, expansion shrinkage rate, particle size distribution, and pH was analyzed. Scanning electron microscopy and X-ray diffraction experiments were used to analyze changes in the lime soil particle structure for different aging times and the formation of new substances. The results show that as aging time increases, the stress–strain curve of the soil softens significantly, shear strength deteriorates, and cohesion decreases. When the aging time is 6 h, the expansion rate and shrinkage rate at the center of the soil sample are the maximum. The volume fracture and expansion shrinkage rates decrease first, and then plateau with aging time, with the changes remaining stable after 72 h; these rate decreases are positively correlated with the change rate of pH. The formation of Ca(OH)2 affects the sample pH, and the changes in pH, Ca(OH)2, and CaO tend to be stable. With an increase in aging time, the proportion of particles of a size less than 0.1 mm decreases, and that of particles of size 0.1–0.5 mm increases. After 72 h of aging, the particle size proportion remains unchanged. Reasonable aging time can, thus, reduce the hydration reaction of lime, improve particle agglomeration effects, and reduce the crack development of the soil.

Details

Language :
English
ISSN :
19961944
Database :
OpenAIRE
Journal :
Materials; Volume 15; Issue 16; Pages: 5785
Accession number :
edsair.doi.dedup.....7fdf488266ef2c3182ee529c7d6dc7db
Full Text :
https://doi.org/10.3390/ma15165785