The scarcity of natural resources, and energy demand/carbon footprints related to their processing and transportation, has led to the quest for alternate materials for road/pavement construction and other infrastructure development. On the other side, landfill mined soil like fraction (LMSF) forms significant proportion of mined legacy landfill waste that exists at different locations around the world; however, it has found limited applications. The present study explores the utilization of LMSF in development of novel asphalt road subbase layers for resilient road infrastructure. 30-60% of LMSF replacement has been studied, and findings based on gradation analysis, compaction tests and California bearing ratio (CBR) tests are quite encouraging. Most combinations of subbase layers studied exceed the design requirements for low volume roads in Indian scenario (rural and outer urban roads); while 30% LMSF in wet mix macadam satisfies the requirements of Indian and other international codes. The cost-benefit analysis shows significant saving in material cost due to utilization of LMSF in road subbase layer. The potential utilization of low cost and sustainable LMSF in asphalt road subbase layer would allow design of superior roads with CBR exceeding design values, resulting in better life cycle performance of road infrastructure with high resilience to fatigue effects, water inundation and overloading conditions.

Landfill mining is emerging as an effective strategy towards mitigation of the problems associated with legacy landfills. About 40-80% of the landfill mined waste is soil-like fraction (landfill mined soil like fraction, LMSF) that is obtained after removing the combustibles and recyclables. However, due to its lower calorific value and presence of organic content, LMSF has not found many applications except landfill cover material and filling of low-lying areas. In this context, the present study explores the strength properties of LMSF with and without fibres (coir and polypropylene fibres) through unconfined compression, direct shear, UU triaxial, cyclic UU triaxial, indirect tension and bending strength tests. Overall, the shear strength properties of LMSF are similar to sand with some cohesion. Further, the performance of LMSF with optimum fibre proportion (2% for coir fibres and 1.5% for polypropylene fibres) is quite superior under monotonic and cyclic compressive loading conditions, as well as indirect tension and flexural loading conditions. An assessment of 1 m replacement of soft soil with LMSF with/without fibre reinforcement infers substantial increase in the allowable bearing pressure of LMSF. Overall, though LMSF may need assessment/pre-treatment (as required) due to presence of organic content and any possible heavy metal concentration, utilization of LMSF would encourage the adoption of landfill mining process. The current research insights contribute in the direction of achieving sustainable infrastructure development by reduction in the landfill area that would reduce the depletion of conventionally utilized natural resources for fill applications such as sand and gravel, and contribute positively towards environment.