PMID- 34601348 OWN - NLM STAT- MEDLINE DCOM- 20211103 LR - 20211103 IS - 1095-8630 (Electronic) IS - 0301-4797 (Linking) VI - 301 DP - 2022 Jan 1 TI - Surface rainfall erosion resistance and freeze-thaw durability of bio-cemented and polymer-modified loess slopes. PG - 113883 LID - S0301-4797(21)01945-9 [pii] LID - 10.1016/j.jenvman.2021.113883 [doi] 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. CI - Copyright (c) 2021 Elsevier Ltd. All rights reserved. FAU - Sun, Xiaohao AU - Sun X AD - Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong. Electronic address: sunxiao14hao@gmail.com. FAU - Miao, Linchang AU - Miao L AD - Institute of Geotechnical Engineering, Southeast University, Nanjing, Jiangsu, 210096, China. Electronic address: Lc.miao@seu.edu.cn. FAU - Chen, Runfa AU - Chen R AD - Beijing Urban Construction Group Co. Ltd, Beijing, 210096, China. Electronic address: 230159539@seu.edu.cn. FAU - Wang, Hengxing AU - Wang H AD - Institute of Geotechnical Engineering, Southeast University, Nanjing, Jiangsu, 210096, China. Electronic address: 576477264@qq.com. FAU - Xia, Jingxin AU - Xia J AD - School of Transportation, Southeast University, Nanjing, Jiangsu, 210096, China. Electronic address: xiajingxin@seu.edu.cn. LA - eng PT - Journal Article DEP - 20210930 PL - England TA - J Environ Manage JT - Journal of environmental management JID - 0401664 RN - 0 (Polymers) RN - 0 (Soil) RN - H0G9379FGK (Calcium Carbonate) SB - IM MH - Calcium Carbonate MH - *Polymers MH - *Soil OTO - NOTNLM OT - Freeze-thaw durability OT - Loess slope OT - Microbially induced calcite precipitation OT - Polyacrylamide OT - Surface erosion EDAT- 2021/10/04 06:00 MHDA- 2021/11/04 06:00 CRDT- 2021/10/03 20:53 PHST- 2021/07/02 00:00 [received] PHST- 2021/09/16 00:00 [revised] PHST- 2021/09/28 00:00 [accepted] PHST- 2021/10/04 06:00 [pubmed] PHST- 2021/11/04 06:00 [medline] PHST- 2021/10/03 20:53 [entrez] AID - S0301-4797(21)01945-9 [pii] AID - 10.1016/j.jenvman.2021.113883 [doi] PST - ppublish SO - J Environ Manage. 2022 Jan 1;301:113883. doi: 10.1016/j.jenvman.2021.113883. Epub 2021 Sep 30.