Slag waste incorporation in high early strength concrete as cement replacement: Environmental impact and influence on hydration & durability attributes

This paper investigates the effects of incorporating slag waste (Ground Granulated Blast Furnace Slag; GGBS) as cement replacement in high early strength concrete. GGBS was used in various replacement ratios and resulting properties of the developed concretes were evaluated. Compressive strength, heat of hydration and shrinkage were determined for evaluating hydration attributes while chloride penetrability and carbonation resistance were investigated for studying the durability-related characteristics of the resulting concretes. The optimum ratio of GGBS as SCM has been determined, in this study, as 30% at which there is merely an average strength decline of 11% while reducing the total carbon dioxide emissions by 30%. Similarly, at this replacement level, the decreased chloride ion penetrability (15%) and higher carbonation resistance (3%) further encourage its use in precast concrete incorporating (HESC). Finally, the beneficial effects of using slag waste in concrete were quantified by determining associated CO2 emissions. It is concluded that slag incorporation in concrete significantly reduces the CO2 emissions, (up to 68%) depending on the cement replacement level, thus promoting green construction and sustainable development.