Sustainable Utilization of Fibre Reinforcement and Magnesia-Activated Slag for Stabilization of LandFill-Mined-Soil-Like-Fraction
Authors :- AS Reddy, VM Rotte, KKR Iyer, TN Dave
Publication :- Geo-environmental Engineering and Unsaturated Soil Mechanics. IGC 2023. Lecture Notes in Civil Engineering, vol 678. Springer
Landfill-mined-soil-like-fraction (LMSF) is the finer fraction obtained from mining of legacy landfills. LMSF has found limited applications due to the presence of organic matter, heavy metals and heterogeneous composition. However, suitable stabilization techniques can be employed to overcome these challenges, and enhance the utilization of LMSF in infrastructure applications. In this regard, the present study evaluates the performance of fibre-reinforced alkali-activated stabilization of LMSF for potential utilization as fill material. An alkali-activated binder comprising magnesia (MgO) and ground granulated blast furnace slag (GGBS) is synthesized to stabilize LMSF along with fibre reinforcement. The inclusion of fibres enhances early and residual strength, and imparts ductility to the stabilized system. An optimum binder percentage of 15% (with GGBS:MgO ratio as 2:1) is obtained based on unconfined compression test (UCS) results. Two types of fibres, viz., polypropylene and coir fibres are selected to represent synthetic and natural fibres, respectively. Different fibre percentages, viz., 0.5%, 1%, 1.5%, 2% and 2.5% are blended along with magnesia-activated slag to evaluate the effect of fibre reinforcement in improving strength, stability and degradation characteristics of LMSF under different environments (viz., normal, alkaline and acidic). The fibre-reinforced alkali-activated stabilization of LMSF has shown about 12–15 times increase in strength, better resistance to deterioration under different environmental conditions, inferring the development of interlocking due to fibres and stable cementitious compounds due to magnesia-activated slag. Thus, fibre-reinforced alkali-activated stabilization of LMSF has potential to contribute towards the development of sustainable infrastructure for future.