Slag Utilization in Pavement Construction

An overall review of the current and potential utilization of ferrous, nonferrous, and boiler slags in pavement structures is given. It would appear that the optimum uses for iron blast furnace slag are in cements and base stabilization processes that take advantage of the energy “invested” in the suitably vitrified slag (granulated or pelletized), rather than bulk aggregate applications. Steelmaking slag that is not recycled can be used to advantage in asphaltic concrete (high stability and skid resistance), and may have applications in base and shoulder stabilization and construction (noting the expansion potential). Nonferrous slags such as copper and nickel slag can be used in granular base and structural fill construction, and related applications such as ballast. Boiler slags are used in a number of applications such as seal coat, asphaltic concrete, and granular base construction. While most ferrous slag is utilized, there is still much scope to utilize nonferrous and boiler slags that are often disposed of with consequent environmental impact. With the present indications of materials and energy shortages, there is a new concern that all byproduct slags be utilized effectively.