Feasibility of incorporating coal mine overburden material as construction-grade fine aggregate

Abstract

This study addresses the environmental challenge posed by coal mine overburden (CMOB) disposal by exploring its viability as a fine aggregate substitute for concrete production, particularly in response to the escalating demand for natural river sand (NS). Physical properties of CMOB, including particle size, specific gravity, density, water absorption, and the presence of deleterious materials, were rigorously evaluated. The results show that while some physical properties differ from NS, crucial parameters such as specific gravity, density, and soundness closely align with NS, all within specified code limits. Chemical-mineralogical analyses reveal the absence of sulfur and chloride in CMOB, mitigating the risk of sulfate and chloride attack on cement mortar/concrete. The study also highlights that CMOB-incorporated mortar exhibits enhanced compressive strength, with an optimum replacement level of 60%. Exceeding this level may elevate water demand in mortar, diminishing strength. This research not only establishes CMOB as a construction-grade fine aggregate but also presents it as a sustainable solution, conserving natural river sand and addressing environmental concerns associated with overburden disposal.

Keywords:

• Coal mine overburden
• industrial waste
• fine aggregate
• chemical-mineralogical properties
• mechanical strength

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.