The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Navid Ranjbar - One of the best experts on this subject based on the ideXlab platform.
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clayey Soil Stabilization using geopolymer and portland cement
Construction and Building Materials, 2018Co-Authors: P. Ghadir, Navid RanjbarAbstract:Abstract This study compares the mechanical performance of clayey Soil Stabilization using volcanic ash (VA) based geopolymer and ordinary Portland cement (OPC). The effects of curing conditions and time, alkali activator/clay and alkali activator molarity, and VA/clay ratio are determined. The compressive strength of the untreated clayey Soil specimens could be increased from 0.2 to 4 MPa and 2 to 12 MPa at the OC and DC conditions, respectively, when the Soil partially replaced by 15 wt% of the binders. It is observed that geopolymer treatment is more efficient at the dry conditions (DC) while the Portland cement is superb at the wet environments (OC). This difference is associated with the role of water and pH in the kinetics of geopolymerization and the Portland cement hydration. Moreover, increasing the molarity of alkali activator and alkali activator/clay improve the compressive strength of the geopolymer treated Soil. Besides, the higher energy absorption in all geopolymer specimens shows the superior ductility of this material in comparison with OPC.
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investigation of Soil Stabilization using chitosan biopolymer
Journal of Cleaner Production, 2018Co-Authors: Nader Hataf, P. Ghadir, Navid RanjbarAbstract:Abstract Recently, chitosan biopolymer has attracted several research attentions in geoenvironmental applications such as absorption of heavy metals in contaminated Soils, reduction of Soil erosion and hydraulic conductivity. However, the influence of chitosan incorporation on mechanical properties of Soil has not been evaluated comprehensively. This study investigates the potential of clay Soil Stabilization using a biocompatible chitosan solution which synthesized from shrimp shell waste. The chitosan solution is used in different concentration to evaluate its potentials on mechanical properties of clay Soil at different curing times and conditions. The results show that incorporation of chitosan has a potential to increase the interparticle interaction of the Soil particles which leads to improved mechanical properties. However, the interparticle interaction is strongly dependent on time and moisture content of the Soil, by which at wet condition chitosan solution provides an extra interaction between particles in early days while it lost its efficiency over times. The bond strength is inefficient at dry condition.
Won-taek Hong - One of the best experts on this subject based on the ideXlab platform.
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Near-surface Soil Stabilization by enzyme-induced carbonate precipitation for fugitive dust suppression
Acta Geotechnica, 2019Co-Authors: Jun Young Song, Jaewon Jang, Won-taek HongAbstract:To resolve the environmental and sustainability issues from fugitive dust emission and conventional mitigation methods, multiple experiments were conducted to evaluate the suppression of fugitive dust and its effect on near-surface Soil Stabilization by enzyme-induced carbonate precipitation (EICP). The optimal recipes for maximum CaCO_3 precipitation with high- and low-purity chemicals were first identified for the EICP treatment. Soil specimens treated with both solutions were characterized by measuring shear wave velocity and cone tip resistance. A wind tunnel test was conducted to examine how the near-surface treatment suppressed particulate matter (PM 2.5 and PM 10) against wind and dynamic impacts. The results showed that both the shear wave velocity and the peak cone tip resistance increased almost linearly with increasing solution volume up to 7 L/m^2. Dust emission was effectively mitigated by increasing solution volume up to 3 L/m^2. Both high- and low-purity chemicals showed a similar ability to suppress fugitive dust. Upon vibration, the treatment effect vanished, but treatment with 7 L/m^2 solution made the Soil remain intact. Scanning electron microscopic imaging confirmed the precipitation of vaterite when low-purity chemicals were used.
P. Ghadir - One of the best experts on this subject based on the ideXlab platform.
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clayey Soil Stabilization using geopolymer and portland cement
Construction and Building Materials, 2018Co-Authors: P. Ghadir, Navid RanjbarAbstract:Abstract This study compares the mechanical performance of clayey Soil Stabilization using volcanic ash (VA) based geopolymer and ordinary Portland cement (OPC). The effects of curing conditions and time, alkali activator/clay and alkali activator molarity, and VA/clay ratio are determined. The compressive strength of the untreated clayey Soil specimens could be increased from 0.2 to 4 MPa and 2 to 12 MPa at the OC and DC conditions, respectively, when the Soil partially replaced by 15 wt% of the binders. It is observed that geopolymer treatment is more efficient at the dry conditions (DC) while the Portland cement is superb at the wet environments (OC). This difference is associated with the role of water and pH in the kinetics of geopolymerization and the Portland cement hydration. Moreover, increasing the molarity of alkali activator and alkali activator/clay improve the compressive strength of the geopolymer treated Soil. Besides, the higher energy absorption in all geopolymer specimens shows the superior ductility of this material in comparison with OPC.
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Investigation of Soil Stabilization using chitosan biopolymer
Journal of Cleaner Production, 2018Co-Authors: Nader Hataf, P. Ghadir, Nosrat RanjbarAbstract:© 2017 Elsevier Ltd Recently, chitosan biopolymer has attracted several research attentions in geoenvironmental applications such as absorption of heavy metals in contaminated Soils, reduction of Soil erosion and hydraulic conductivity. However, the influence of chitosan incorporation on mechanical properties of Soil has not been evaluated comprehensively. This study investigates the potential of clay Soil Stabilization using a biocompatible chitosan solution which synthesized from shrimp shell waste. The chitosan solution is used in different concentration to evaluate its potentials on mechanical properties of clay Soil at different curing times and conditions. The results show that incorporation of chitosan has a potential to increase the interparticle interaction of the Soil particles which leads to improved mechanical properties. However, the interparticle interaction is strongly dependent on time and moisture content of the Soil, by which at wet condition chitosan solution provides an extra interaction between particles in early days while it lost its efficiency over times. The bond strength is inefficient at dry condition.
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investigation of Soil Stabilization using chitosan biopolymer
Journal of Cleaner Production, 2018Co-Authors: Nader Hataf, P. Ghadir, Navid RanjbarAbstract:Abstract Recently, chitosan biopolymer has attracted several research attentions in geoenvironmental applications such as absorption of heavy metals in contaminated Soils, reduction of Soil erosion and hydraulic conductivity. However, the influence of chitosan incorporation on mechanical properties of Soil has not been evaluated comprehensively. This study investigates the potential of clay Soil Stabilization using a biocompatible chitosan solution which synthesized from shrimp shell waste. The chitosan solution is used in different concentration to evaluate its potentials on mechanical properties of clay Soil at different curing times and conditions. The results show that incorporation of chitosan has a potential to increase the interparticle interaction of the Soil particles which leads to improved mechanical properties. However, the interparticle interaction is strongly dependent on time and moisture content of the Soil, by which at wet condition chitosan solution provides an extra interaction between particles in early days while it lost its efficiency over times. The bond strength is inefficient at dry condition.
Jun Young Song - One of the best experts on this subject based on the ideXlab platform.
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Near-surface Soil Stabilization by enzyme-induced carbonate precipitation for fugitive dust suppression
Acta Geotechnica, 2019Co-Authors: Jun Young Song, Jaewon Jang, Won-taek HongAbstract:To resolve the environmental and sustainability issues from fugitive dust emission and conventional mitigation methods, multiple experiments were conducted to evaluate the suppression of fugitive dust and its effect on near-surface Soil Stabilization by enzyme-induced carbonate precipitation (EICP). The optimal recipes for maximum CaCO_3 precipitation with high- and low-purity chemicals were first identified for the EICP treatment. Soil specimens treated with both solutions were characterized by measuring shear wave velocity and cone tip resistance. A wind tunnel test was conducted to examine how the near-surface treatment suppressed particulate matter (PM 2.5 and PM 10) against wind and dynamic impacts. The results showed that both the shear wave velocity and the peak cone tip resistance increased almost linearly with increasing solution volume up to 7 L/m^2. Dust emission was effectively mitigated by increasing solution volume up to 3 L/m^2. Both high- and low-purity chemicals showed a similar ability to suppress fugitive dust. Upon vibration, the treatment effect vanished, but treatment with 7 L/m^2 solution made the Soil remain intact. Scanning electron microscopic imaging confirmed the precipitation of vaterite when low-purity chemicals were used.
Jaewon Jang - One of the best experts on this subject based on the ideXlab platform.
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Near-surface Soil Stabilization by enzyme-induced carbonate precipitation for fugitive dust suppression
Acta Geotechnica, 2019Co-Authors: Jun Young Song, Jaewon Jang, Won-taek HongAbstract:To resolve the environmental and sustainability issues from fugitive dust emission and conventional mitigation methods, multiple experiments were conducted to evaluate the suppression of fugitive dust and its effect on near-surface Soil Stabilization by enzyme-induced carbonate precipitation (EICP). The optimal recipes for maximum CaCO_3 precipitation with high- and low-purity chemicals were first identified for the EICP treatment. Soil specimens treated with both solutions were characterized by measuring shear wave velocity and cone tip resistance. A wind tunnel test was conducted to examine how the near-surface treatment suppressed particulate matter (PM 2.5 and PM 10) against wind and dynamic impacts. The results showed that both the shear wave velocity and the peak cone tip resistance increased almost linearly with increasing solution volume up to 7 L/m^2. Dust emission was effectively mitigated by increasing solution volume up to 3 L/m^2. Both high- and low-purity chemicals showed a similar ability to suppress fugitive dust. Upon vibration, the treatment effect vanished, but treatment with 7 L/m^2 solution made the Soil remain intact. Scanning electron microscopic imaging confirmed the precipitation of vaterite when low-purity chemicals were used.
