TY - JOUR
T1 - Surface rainfall erosion resistance and freeze-thaw durability of bio-cemented and polymer-modified loess slopes
AU - Sun, Xiaohao
AU - Miao, Linchang
AU - Chen, Runfa
AU - Wang, Hengxing
AU - Xia, Jingxin
N1 - Funding Information:
The authors thank the valuable comments from the reviewers. This study was funded by National Natural Science Foundation of China (grant number 51578147 ), Fundamental Research Funds for the Central Universities (grant number 2242020R20025 ), Science and Technology Department of Ningxia (grant number 2020BFG02014 ), and Transportation Department of Ningxia (grant number 202000173 ).
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/1/1
Y1 - 2022/1/1
N2 - Microbially induced calcite precipitation (MICP) has been shown to mitigate sand erosion; however, few studies have applied MICP on loess soils. In this study, polyacrylamide (PAM) was added to the cementation solution, and combined MICP-PAM treatment was applied to improve the surface erosion resistance of loess-slopes. The freeze-thaw (FT) durability of MICP-PAM treated loess slopes was also studied. The obtained results showed that MICP-PAM treatment improved erosion resistance and addition of 1.5 g/L PAM achieved the best erosion control and highest surface strength. The high erosion resistance of MICP-PAM treated slopes could be attributed to the stable spatial structure of precipitation, and PAM addition conveyed stronger resistance to tension or shear force. With increasing number of FT cycles, the surface strength of MICP-PAM treated loess slopes decreased; however, slopes subjected to 12 FT cycles still only lost little soil. In MICP-PAM treated loess slopes, cracks and pores evolved with increasing number of FT cycles. With increasing number of FT cycles, porosity and fractal dimension increased, pore ellipticity decreased slightly, and the percentage of various pores changed slightly. The number of FT cycles had less effect on MICP-PAM treated loess slopes than on untreated slopes. MICP-PAM treatment significantly mitigated surface erosion of loess-slopes and improved FT weathering resistance, thus presenting promising potential for application in the field. In addition, based on the linear correlations between surface strength and rainfall-erosion resistance, surface strength could be measured to evaluate the rainfall-erosion resistance for MICP-PAM treated slopes in practical engineering applications.
AB - Microbially induced calcite precipitation (MICP) has been shown to mitigate sand erosion; however, few studies have applied MICP on loess soils. In this study, polyacrylamide (PAM) was added to the cementation solution, and combined MICP-PAM treatment was applied to improve the surface erosion resistance of loess-slopes. The freeze-thaw (FT) durability of MICP-PAM treated loess slopes was also studied. The obtained results showed that MICP-PAM treatment improved erosion resistance and addition of 1.5 g/L PAM achieved the best erosion control and highest surface strength. The high erosion resistance of MICP-PAM treated slopes could be attributed to the stable spatial structure of precipitation, and PAM addition conveyed stronger resistance to tension or shear force. With increasing number of FT cycles, the surface strength of MICP-PAM treated loess slopes decreased; however, slopes subjected to 12 FT cycles still only lost little soil. In MICP-PAM treated loess slopes, cracks and pores evolved with increasing number of FT cycles. With increasing number of FT cycles, porosity and fractal dimension increased, pore ellipticity decreased slightly, and the percentage of various pores changed slightly. The number of FT cycles had less effect on MICP-PAM treated loess slopes than on untreated slopes. MICP-PAM treatment significantly mitigated surface erosion of loess-slopes and improved FT weathering resistance, thus presenting promising potential for application in the field. In addition, based on the linear correlations between surface strength and rainfall-erosion resistance, surface strength could be measured to evaluate the rainfall-erosion resistance for MICP-PAM treated slopes in practical engineering applications.
KW - Freeze-thaw durability
KW - Loess slope
KW - Microbially induced calcite precipitation
KW - Polyacrylamide
KW - Surface erosion
UR - http://www.scopus.com/inward/record.url?scp=85115985487&partnerID=8YFLogxK
U2 - 10.1016/j.jenvman.2021.113883
DO - 10.1016/j.jenvman.2021.113883
M3 - Journal article
C2 - 34601348
AN - SCOPUS:85115985487
SN - 0301-4797
VL - 301
JO - Journal of Environmental Management
JF - Journal of Environmental Management
M1 - 113883
ER -