Study of Some Characteristics of Blended Cement Containing Industrial Wastes

Abstract

This work aims to study some hydration characteristics of blended cement containing some industrial wastes using ordinary Portland cement (OPC) with granulated blast furnace slag (GBFS) and/or silica fume (SF) and/or fly ash (FA). Various mixes are prepared using OPC with slag using the ratios 0, 15, 30 and 45% and OPC with silica fume (SF) or fly ash (FA) using the ratios, 0, 5,10 and 15% . Also the following mixes were prepared; (80% OPC + 15% slag + 5% SF), (80% OPC + 15% slag + 5% FA) and (75% OPC + 15% slag + 5% SF + 5% FA). The hydration characteristics of the different mixes were tested via determination of water of consistency, setting times, compressive strength values, combined water contents, x-ray diffraction and thermal analysis. In addition, the fire resistance of the hardened pastes of the different mixes were examined at various temperatures. The fire resistance was evaluated by the determination of compressive strength, combined water content and XRD analysis. The results showed thatblended cement containing 15% slag and 85% OPC give the highest compressive strength values and the highest resistance to heat treatment up to 500oC. The optimum amount of silica fume and fly ash that give the best result is 5%. The highest compressive strength values are obtained with mixes containing 15% slag + 5% fly ash + 80% OPC and also 15% slag + 5% fly ash + 5% silica fume + 75% OPC. All the prepared blends have high resistance to heating up to 500oC compared to the blank mix