Reuse of thermal power plant slag in hot bituminous mixes

The revalorization of industrial waste plays a key role in the solution of environmental and economic problems in the construction sector, thus actions contributing to the symbiosis between industries in the same region are of great benefit since they optimize resources in the area and also open the door to new business opportunities. In recent years, the electricity produced by thermal power stations has become a renewable energy source of great potential. Nevertheless, this type of energy is not without drawbacks because of the coal ash and boiler slag produced by coal combustion. Although the ash has different application as a construction material, boiler slag is more problematic since it must be deposited at landfills. The accumulation of this waste has become a serious economic and environmental problem. This paper presents the results of a research project, which analyzed the viability of reusing thermal power plant slag as a substitute for natural aggregate in the manufacture of hot mix asphalt (HMA). For this purpose, the waste was first characterized and tested in the laboratory with a view to its subsequent use in HMA. Based on the positive laboratory results, a test road section was built with this material so that its performance could be compared with that of the road section paved with a conventional HMA. The results obtained confirmed the aptness of thermal power plant slag for use in road construction.