An experimental study of mitigating coastal sand dune erosion by microbial- and enzymatic-induced carbonate precipitation

Liu, Kaiwei; Jiang, Ning‐Jun; Qin, Junde; Wang, Yi-Jie; Tang, Chao‐Sheng; Han, Xiao-Le

doi:10.1007/s11440-020-01046-z

Cited by 111 publications

(33 citation statements)

References 45 publications

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“…1 εf is the strain corresponding to the peak stress, 2 E50 is the secant modulus at 50% of the UCS, 3 αc and 4 αs are the increasing proportion of CCC and UCS after adding fiber compared with that of traditional EICP-treated samples. 5 βcc and 6 βsc represent the increased ratios of CCC and UCS higher than that at the previous fiber content, 7 βcl and 8 βsl represent the increased percentages of CCC and UCS higher than that of the former fiber length, respectively. Negative values in the last four columns indicate a decrease in strength.…”

Section: And Its Spatial Distributionmentioning

confidence: 99%

“…Both technologies are widely used in soil reinforcement [ 4 , 5 , 6 ]. Previous scholars [ 7 , 8 ] have successfully used PVA fiber to improve cement-based composites. In order to compensate for the undesirable weakness of the brittle failure and low residual strength of biocemented soil, researchers have attempted to combine MICP technology with fiber reinforcement.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Incorporating Polyvinyl Alcohol Fiber on the Mechanical Properties of EICP-Treated Sand

et al. 2021

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Enzyme-induced calcium carbonate precipitation (EICP) technology can improve the strength of treated soil. But it also leads to remarkable brittleness of the soil. This study used polyvinyl alcohol (PVA) fiber combined with EICP to solidify sand. Through the unconfined compressive strength (UCS) test, the effect of PVA fiber incorporation on the mechanical properties of EICP-solidified sand was investigated; the distribution of CaCO3 in the sample and the microstructure of fiber-reinforced EICP-treated sand were explored through the calcium carbonate content (CCC) test and microscopic experiment. Compared with the sand treated by EICP, the strength and stiffness of the sand reinforced by the fiber combined with EICP were greatly improved, and the ductility was also improved to a certain extent. However, the increase of CCC was extremely weak, and the inhomogeneity of CaCO3 distribution was enlarged; the influence of fiber length on the UCS and CCC of the treated sand was greater than that of the fiber content. The improvement of EICP-solidified sand by PVA fiber was mainly due to the formation of a “fiber–CaCO3–sand” spatial structure system through fiber bridging, not the increase of CCC.

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Section: And Its Spatial Distributionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Incorporating Polyvinyl Alcohol Fiber on the Mechanical Properties of EICP-Treated Sand

et al. 2021

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“…Recent studies evidenced that MICP technique could promote the cover condition of the slope, providing a marked increase in stability of surface substrates against various slope degradation processes. For example, the enhancement in scouring resistance of MICP treated foreshore slopes was demonstrated under simulated tidal waves (Salifu et al 2016;Bao et al 2017;Liu et al 2020). Jiang et al (2019) assessed the erodibility under rainfall effects, suggesting that treatment by 1 mol/L cementation media could provide better erosion resistance among 0.2-2 mol/L.…”

Section: Introductionmentioning

confidence: 99%

Durability analysis of bio-cemented slope soil under the exposure of acid rain

2021

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Purpose Instability of slope surface is a critical concern in Geotechnical and Environmental Engineering. MICP (Microbial-Induced Carbonate Precipitation), an innovative bio-cementation technique, has attracted the attention for slope surface protection. In this work, MICP was investigated to evaluate its durability under the exposure of acid rain and to advance the understanding on long-term performance of slope soil preserved by MICP. Methods MICP treatment was applied to a fine-grained slope soil using indigenous bacteria. Specimens treated to different cementation levels (% CaCO3) were exposed to acid rain (of varying pH) through two sorts of mechanisms: (i) infiltration and (ii) immersion. The evaluations were based on corrosion of CaCO3, mass loss, needle penetration tests, and scanning electron microscopy. Results The decrease in pH increased the corrosion of CaCO3, resulting in considerable loss in aggregate and unconfined compressive strength. However, increased cementation level showed high durability of specimens. The soils treated to 12.5% CaCO3 showed 19.9% soil loss, whereas it was reduced to 5.4% when cemented to 22.5% CaCO3. The results also revealed that the contact time of acid rain significantly governed the rate of corrosion, i.e., specimens subjected to lower infiltration rate (20 mm/h) showed higher loss of mass compared to that of higher rate (100 mm/h). Conclusion The long-term performance of MICP treatment is determined by (i) cementation level, (ii) pH, and (iii) infiltration rate of acid rain. High cementation level promotes the longevity of the treatment. Therefore, MICP to higher cementation level is recommended for long-term preservation of slope surface.

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“…Surface erosion is a common slope degradation process; therefore, most of the existing studies focused on the responses under simulated rainfalls and wave effects. It was repeatedly shown that the MICP can significantly improve the erosion and scouring resistance of foreshore slopes when subjected to tidal wave effects (Salifu et al 2016;Bao et al 2017;Liu et al 2020). In due course, few researchers assessed the impact of short-term rainfall on the surface erosion of sandy slopes (Jiang et al 2019;Chung et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Effect of wetting and drying cycles on the durability of bio-cemented soil of expressway slope

Gowthaman

Nakashima

Kawasaki

2021

Int. J. Environ. Sci. Technol.

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Cyclic wet-dry is one of the influential weathering agents which can rapidly alter the mechanical properties of soils, limiting their durability and consistent performance. This study investigates the effect of wet-dry cycles on the mechanical behaviour of bio-cemented soil. Microbial-induced carbonate precipitation-based bio-cementation is an innovative soil improvement method, which is gaining increasing attention as a potential alternative for stabilizing slope surface. As the treated surfaces are exposed to repeated rainfalls and draughts, durability analysis is essential; cyclic wet-dry tests were therefore performed as a credible indicator of durability. The soil obtained from the Hokkaido expressway slope was treated at laboratory to varying cementation levels (% CaCO3) and subjected to 50 subsequent wet-dry cycles. Physical and mechanical changes were monitored using mass loss, shear wave velocities and needle penetration tests during wet-dry cycles. The results showed that the wet-dry cycles deteriorated the physical and mechanical at two stages. The mass and S-wave velocity of specimens significantly dropped after first few cycles and then tended to reach equilibrium. The second stage of notable deterioration was observed between 30 and 50 wet-dry cycles. It is suggested that the erosion of weak and powdery deposition of CaCO3 causes the degradation at the early stage, whereas the degradation in the late stage was attributed to the microstructural deformations of intact carbonate bonds. It was also found that the increase in cementation level decreases the deterioration of bio-cemented soil under wet-dry cycles.

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An experimental study of mitigating coastal sand dune erosion by microbial- and enzymatic-induced carbonate precipitation

Cited by 111 publications

References 45 publications

Effect of Incorporating Polyvinyl Alcohol Fiber on the Mechanical Properties of EICP-Treated Sand

Effect of Incorporating Polyvinyl Alcohol Fiber on the Mechanical Properties of EICP-Treated Sand

Durability analysis of bio-cemented slope soil under the exposure of acid rain

Effect of wetting and drying cycles on the durability of bio-cemented soil of expressway slope

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