Utilization of Coal Gangue for Earthworks: Sustainability Perspective

Abstract

In recent years, there is a growing trend to utilize industrial residues/wastes with the aim of conserving natural resources. However, the environmental impacts in the form of carbon emission associated with their utilization ought to be predetermined prior to their promotion as a sustainable alternative to natural materials. This study aims to quantify the environmental impacts associated with the application of coal gangue (CG) in earthworks by performing carbon footprint analysis (CFA) and cost analysis (CA). An ongoing project of reinforced earthwork construction undertaken by the Government of Telangana, India, has been considered for the CFA and CA of coal gangue utilization. Prior to the CFA and CA, the feasibility of using CG for reinforced earth wall was ascertained by studying its geotechnical characteristics. Additionally, CFA was also performed to quantify the carbon emission associated with the disposal activity of unused CG. Results revealed that CG exhibited favorable geotechnical properties to enable its applications in earthworks. The CFA results indicate that the procurement and haulage of raw materials accounted for maximum carbon emissions and utilization of CG can eliminate 361 CO2eq (kg) associated with its disposal. Further, the CA revealed that CG utilization in earthworks results in Re 3333/m3 reduction in cost of construction. Furthermore, the results of the study revealed that the utilization of CG can lead to a significant decrease in the carbon footprints by eliminating the carbon emission associated with disposal of CG, thus creating a positive impact on the environment.