Using Iron Slag and Cement Bypass Wastes as Resources to Produce Wollastonite-Based Construction Materials

Solid wastes with negative environmental impacts can be transformed into valuable building materials. The current study presents an experimental investigation into the properties of ground granulated blast furnace slag (GGBFS) and cement bypass dust (CBD), which are industrial solid waste materials, for use in the manufacture of construction materials. Broad range of binary mix compositions of both wastes were examined across fire temperatures, up to 1,250°C. The sintered mixes were examined in terms of their phase, electrical, and microstructural properties of the prepared samples. Additionally, the performance characterizations, including microhardness and physical properties of the studied mixes were determined. At the later temperature, calcium silicates, wollastonite, melilite, and spurrite were developed through the sintering process. Additionally, the microstructure exhibits submicron and nanoscale round and lath-shaped particles, sometimes arranged in clusters. Bulk density, apparent porosity, and water absorption were 2.01–2.57 g/cm3, 1.87–12.52%, and 0.93–4.87% ranges, respectively. The microhardness of the mix samples ranged from 100 to 350 kgf/mm2. Raman spectroscopy confirmed the presence of calcium silicate phases. The densification behavior increased with the GGBFS content in the sintered mix samples. The 25 (bypass):75 (GGBFS) mix sample showed optimum physical and mechanical properties, with a micro-hardness of 320 kgf/mm2. The dielectric properties show that some sintered mix samples are considered good insulators.