A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Performance Evaluation of Fiber-Reinforced Expansive Subgrade Soil Stabilized with Alkali Activated Binder, Lime, and Cement: A Comparative Study
Expansive subgrade soil exhibits a high degree of volumetric instability upon periodic moisture fluctuation, resulting in low bearing strength and loss of pavement serviceability. However, the use of conventional binders has a significant impact on the atmosphere by releasing greenhouse gases. In the present study, an attempt is made to enhance the strength characteristics of the expansive subgrade soil by stabilizing with an eco-friendly alkali activated binder (AAB) reinforced by two distinct types of fibers, polypropylene (PF) and chemically treated hemp fiber (CHF). The research also compares PF and THF reinforcement's effectiveness in AAB with the conventional lime and cement binders. AAB is synthesized by adding an aluminosilicate precursor (slag and low calcium fly ash) to the alkali activator solution for sodium hydroxide and sodium silicates. In the alkaline binder, a minimum water to solids ratio (w/s) of 0.4 is maintained. The effects of varying PF and CHF content in lime, cement, and slag-fly ash-based AAB soil mixture is evaluated through a series of tests, including swelling potential, compressive shear, strength, and penetration resistance tests. California bearing ratio (CBR) is chosen as a subgrade performance indicator for both PF and CHF reinforced soil. Reliability analysis using Monte Carlo Simulation (MCS) is further conducted to determine indices for CBR and strength tests that help to analyze the impact of uncertainties associated with the design of the fiber-reinforced AAB treated subgrade layer. Microstructural and morphological studies are carried out for lime, cemented, and AAB treated soil reinforced with PF and CHF. It is observed that PF reinforced soil has achieved a higher interfacial bonding with strong interlocking density under low tensile and shrinkage cracking compared to other fibers. The study also shows that the subgrade strength improvement under higher fiber dosages is prominent when AAB is used as an additive compared to lime and cement. The reliability analysis results show that the optimum dosages of fiber and slag-fly ash ratio in AAB-soil mixture are essential factors for strengthening the subgrade parameters.
Performance Evaluation of Fiber-Reinforced Expansive Subgrade Soil Stabilized with Alkali Activated Binder, Lime, and Cement: A Comparative Study
Expansive subgrade soil exhibits a high degree of volumetric instability upon periodic moisture fluctuation, resulting in low bearing strength and loss of pavement serviceability. However, the use of conventional binders has a significant impact on the atmosphere by releasing greenhouse gases. In the present study, an attempt is made to enhance the strength characteristics of the expansive subgrade soil by stabilizing with an eco-friendly alkali activated binder (AAB) reinforced by two distinct types of fibers, polypropylene (PF) and chemically treated hemp fiber (CHF). The research also compares PF and THF reinforcement's effectiveness in AAB with the conventional lime and cement binders. AAB is synthesized by adding an aluminosilicate precursor (slag and low calcium fly ash) to the alkali activator solution for sodium hydroxide and sodium silicates. In the alkaline binder, a minimum water to solids ratio (w/s) of 0.4 is maintained. The effects of varying PF and CHF content in lime, cement, and slag-fly ash-based AAB soil mixture is evaluated through a series of tests, including swelling potential, compressive shear, strength, and penetration resistance tests. California bearing ratio (CBR) is chosen as a subgrade performance indicator for both PF and CHF reinforced soil. Reliability analysis using Monte Carlo Simulation (MCS) is further conducted to determine indices for CBR and strength tests that help to analyze the impact of uncertainties associated with the design of the fiber-reinforced AAB treated subgrade layer. Microstructural and morphological studies are carried out for lime, cemented, and AAB treated soil reinforced with PF and CHF. It is observed that PF reinforced soil has achieved a higher interfacial bonding with strong interlocking density under low tensile and shrinkage cracking compared to other fibers. The study also shows that the subgrade strength improvement under higher fiber dosages is prominent when AAB is used as an additive compared to lime and cement. The reliability analysis results show that the optimum dosages of fiber and slag-fly ash ratio in AAB-soil mixture are essential factors for strengthening the subgrade parameters.
Performance Evaluation of Fiber-Reinforced Expansive Subgrade Soil Stabilized with Alkali Activated Binder, Lime, and Cement: A Comparative Study
Sustain. Civil Infrastruct.
Steyn, Wynand JvdM (editor) / Wang, Zhixin (editor) / Holleran, Glynn (editor) / Syed, Mazhar (author) / GuhaRay, Anasua (author) / Garg, Ankit (author)
Civil Infrastructures Confronting Severe Weathers and Climate Changes Conference ; 2021 ; NanChang, China
Transportation Infrastructure Engineering, Materials, Behavior and Performance ; Chapter: 8 ; 118-139
2021-07-11
22 pages
Article/Chapter (Book)
Electronic Resource
English
| Taylor & Francis Verlag | 2022
| British Library Conference Proceedings | 2022