Mechanical and structural assessment of hot mix bituminous mixtures containing waste foundry sand

ABSTRACT

Waste foundry sand (WFS) are industrial by-products from the foundry process which represent challenges for environmental departments with respect to the proper disposal in landfills due to their high production. The road infrastructure such as asphalt paving is a major consumer of mineral aggregates originating from the mining activity of exhaustible natural resources. Thus, the WFS reuse for the construction of roads is an alternative to discarding of waste and a reduction in the use of mineral aggregates. In this article hot mix bituminous (HMB) mixtures were produced containing WFS (by weight) substitution contents in relation to manufactured sand of 25%, 50%, 75% and 100% from two origins: industrial landfill and the steel industry; after mechanical and gyratory compaction, these cylindrical specimens were subjected to mechanical tests of splitting tensile strength and resilient modulus obtaining very similar performances as that of the control mixture (which did not contain WFS). These mechanical results as well as the microstructural characterisation of this HMB containing residue led to the conclusion that the reuse of WFS in the asphalt pavement is technically viable, creating an alternative to by-product disposal and reduction of the financial-environmental costs of highways.

KEYWORDS:

• Waste foundry sand
• industrial waste
• asphalt paving
• hot mix bituminous mixtures
• sustainability in construction

Acknowledgments

Thanks to the Aeronautical Technology Institute (ITA) for their technical and academic support, to the CCR-Nova Dutra consortium’s research laboratory for mechanical testing on asphalt concrete, to the Institute for Advanced Studies (IEAv) for assistance in some trials at the National Institute for Space Research (INPE) and for assistance with SEM/EDS analysis and Essencis Ecosystems LTDA for providing WFS.

Disclosure statement

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

Additional information

Funding

This work was financially supported by the Applied Research Foundation (CAPES).