Use of BOF slag and blast furnace dust in asphalt concrete: an alternative for the construction of pavements

Abstract

The boom in the construction of large engineering works has boosted the demand for steel, which has generated an increase in the production of steel waste, a situation that causes environmental problems due to the accumulation and inadequate disposal of these by-products. The use of recycled materials in different processes must be focused on sustainable development and the protection of the environment. This work was developed with the objective of studying the use of Basic Oxygen Furnace slag (BOF) and Blast Furnace Dust (BFD) to manufacture asphalt hot mixes for pavements as an alternative to mitigate the environmental problems derived from the accumulation of this steel waste and the exploitation of non-renewable materials, such as gravel and sand. To achieve the objective, three types of asphalt mixtures were analyzed, a mixture with conventional materials (control) and two mixtures that partially and totally replace the coarse aggregate with BOF and the fine aggregate with BFD. The design of the mixtures was made with the RAtional Methodology for COmpacted geomaterials' DEnsification and Strength Analysis (RAMCODES), which is based on the principle of the vacuum polygon. Tests were carried out to evaluate the physical characteristics and the susceptibility to water and plastic deformation of each type of mixture. The results of this study indicate that it is feasible to use the analyzed steel residues to partially replace conventional aggregates in road paving.

Keywords

• steel waste
• BOF slag
• blast furnace dust
• asphalt concrete