A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
The Effect of Chemical Concentration on the Strength and Erodibility of MICP Treated Sands
Sandy slopes supporting coastal roadways are susceptible to failure during large storm events due to erosion and slope stability. Investigating the application of a natural and sustainable soil improvement method is required to increase the shear strength and erosion resistance of sands while having less impact on the coastal ecology. Microbial induced calcium carbonate precipitation (MICP) is a novel and promising soil improvement technique that utilizes indigenous soil bacteria to hydrolyze urea and induce calcium carbonate precipitation, which improves the mechanical properties of the soil. The chemical concentrations and recipe ratios used for this process can affect the level of improvement. This study aims to draw a relationship between the chemical ratios, shear strength, and erodibility resistance of MICP treated sands. In an attempt to tailor the laboratory experiments closer to field requirements, industrial grade chemicals were used to treat the soil specimens. A submerged impinging jet system was used to evaluate the erodibility parameters of soil specimens treated with different ratios of urea to calcium chloride. Unconfined compression strength tests (UCS), an indication of shear strength, were performed on specimens with similar properties treated with different ratios of urea to calcium chloride. Shear wave velocity measurements were used to detect the level of improvement in all soil specimens during the treatment. The results indicate that the ratio of urea to calcium chloride can affect the number of treatments required to reach a target level of improvement. In addition, the ratio of chemical concentrations can change the erosion strength differently compared to the UCS. These results can also provide a basis for choosing an optimum treatment recipe for field application, by keeping a balance between the mechanical properties of MICP treated soils, mass of calcium carbonate, and cost of chemicals used for treatment.
The Effect of Chemical Concentration on the Strength and Erodibility of MICP Treated Sands
Sandy slopes supporting coastal roadways are susceptible to failure during large storm events due to erosion and slope stability. Investigating the application of a natural and sustainable soil improvement method is required to increase the shear strength and erosion resistance of sands while having less impact on the coastal ecology. Microbial induced calcium carbonate precipitation (MICP) is a novel and promising soil improvement technique that utilizes indigenous soil bacteria to hydrolyze urea and induce calcium carbonate precipitation, which improves the mechanical properties of the soil. The chemical concentrations and recipe ratios used for this process can affect the level of improvement. This study aims to draw a relationship between the chemical ratios, shear strength, and erodibility resistance of MICP treated sands. In an attempt to tailor the laboratory experiments closer to field requirements, industrial grade chemicals were used to treat the soil specimens. A submerged impinging jet system was used to evaluate the erodibility parameters of soil specimens treated with different ratios of urea to calcium chloride. Unconfined compression strength tests (UCS), an indication of shear strength, were performed on specimens with similar properties treated with different ratios of urea to calcium chloride. Shear wave velocity measurements were used to detect the level of improvement in all soil specimens during the treatment. The results indicate that the ratio of urea to calcium chloride can affect the number of treatments required to reach a target level of improvement. In addition, the ratio of chemical concentrations can change the erosion strength differently compared to the UCS. These results can also provide a basis for choosing an optimum treatment recipe for field application, by keeping a balance between the mechanical properties of MICP treated soils, mass of calcium carbonate, and cost of chemicals used for treatment.
The Effect of Chemical Concentration on the Strength and Erodibility of MICP Treated Sands
Ghasemi, Pegah (author) / Zamani, Atefeh (author) / Montoya, Brina (author)
Eighth International Conference on Case Histories in Geotechnical Engineering ; 2019 ; Philadelphia, Pennsylvania
Geo-Congress 2019 ; 241-249
2019-03-21
Conference paper
Electronic Resource
English
The Effect of Chemical Concentration on the Strength and Erodibility of MICP Treated Sands
| British Library Conference Proceedings | 2019
Undrained Monotonic Shear Response of MICP-Treated Silty Sands
| British Library Online Contents | 2018