Effects of freeze-thaw cycling on the engineering properties of vegetation concrete

Yueshu Yang; Jinshun Chen; Tianli Zhou; Daxiang Liu; Qi Yang; Hai Xiao; Deyu Liu; Jiangang Chen; Zhenyao Xia; Wennian Xu

doi:10.1016/j.jenvman.2023.118810

Effects of freeze-thaw cycling on the engineering properties of vegetation concrete

J Environ Manage. 2023 Nov 1:345:118810. doi: 10.1016/j.jenvman.2023.118810. Epub 2023 Aug 16.

Authors

Yueshu Yang¹, Jinshun Chen², Tianli Zhou², Daxiang Liu³, Qi Yang⁴, Hai Xiao², Deyu Liu², Jiangang Chen⁵, Zhenyao Xia², Wennian Xu²

Affiliations

¹ Key Laboratory of Geological Hazards on Three Gorges Reservoir Area (China Three Gorges University), Ministry of Education, Yichang, 443002, PR China; College of Civil Engineering & Architecture, China Three Gorges University, China; Hubei Provincial Engineering Research Center of Slope Habitat Construction Technique Using Cement-Based Materials, China Three Gorges University, Yichang, 443002, Hubei, China.
² Key Laboratory of Geological Hazards on Three Gorges Reservoir Area (China Three Gorges University), Ministry of Education, Yichang, 443002, PR China; College of Civil Engineering & Architecture, China Three Gorges University, China.
³ Key Laboratory of Geological Hazards on Three Gorges Reservoir Area (China Three Gorges University), Ministry of Education, Yichang, 443002, PR China; Key Laboratory of Mountain Hazards and Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, PR China; Hubei Provincial Engineering Research Center of Slope Habitat Construction Technique Using Cement-Based Materials, China Three Gorges University, Yichang, 443002, Hubei, China. Electronic address: ldx@ctgu.edu.cn.
⁴ Power China Guiyang Engineering Corporation Limited, Guizhou Province, Guiyang, 550081, China.
⁵ Key Laboratory of Mountain Hazards and Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, PR China.

PMID: 37595461
DOI: 10.1016/j.jenvman.2023.118810

Abstract

Vegetation concrete has been widely applied for the ecological restoration of bare steep slopes in short-term frozen and non-frozen soil regions in China. However, field experiments conducted in seasonally frozen soil regions have revealed decreases in the bulk density, nutrient content and vegetation coverage. This study aimed to clarify the evolution process and mechanism of the engineering properties of vegetation concrete under atmospheric freeze-thaw (F-T) test conditions. The physical, mechanical, and nutrient properties of vegetation concrete were investigated using six F-T cycles (0, 1, 2, 5, 10 and 20) and two initial soil water contents (18 and 22%). The results revealed decreases in the acoustic wave velocity and cohesive forces and an increase in the permeability coefficient of the vegetation concrete owing to F-T action. X-ray diffraction tests indicated that the decreased cohesive force was closely related to the overall decrease in the content of gelling hydration products in the vegetation concrete. Additionally, the contents of NH₄⁺-N, PO₄³-P and K⁺ in the vegetation concrete increased, whereas that of NO₃^--N decreased. The loss rates of these soluble nutrients increased, indicating that the nutrient retention capacity of the vegetation concrete had decreased. Specifically, the decreased nutrient retention capacity was mainly related to the disintegration and fragmentation of larger aggregates due to F-T action. This study provides theoretical support for future research on improving the anti-freezing capability of ecological slope protection substrates in seasonally frozen soil regions.

Keywords: Freeze-thaw cycling; Nutrient properties; Physical and mechanical properties; Slope ecological protection; Vegetation concrete.

MeSH terms

China
Climate
Engineering
Soil* / chemistry
Water*

Substances

Soil
Water