Hydration characteristics of cement pastes incorporating electric arc-furnace slag

This paper presents the results of a comparative study of the hydration characteristics of cement pastes incorporating steel slag or ground granulated blastfurnace slag (GGBS) as substitutes for ordinary Portland cement (OPC). The study looked at the physical and chemical characteristics of the starting materials. Various cementitious paste mixes were manufactured and cured under two separate curing regimes, and a combination of thermogravimetric and X-Ray diffraction analysis was used to identify the hydration products formed during the investigation. The study established that the partial replacement of OPC with Electric Arc-Furnace steel slag or GGBS leads to a slow rate of formation of hydration products at early ages. However, at later ages, mixtures containing GGBS and waste slag produced more hydration products than the control OPC mix, especially when cured under a hot humid (Mediterranean) climate. The results suggest the viability of application of such industrial waste products in concrete which, among others, is likely to have an important impact on waste utilisation strategy and a dual benefit of reducing the possible negative environmental impact and preservation of natural resources.