Enhanced Early Strength and Performances of GGBFS -Based Alkali -Activated Self -Compacting Low Carbon Concrete

Due to the construction industry's dependency on Portland cement, approximately ۵ -۸% of global CO₂ emissions are attributed to its production, which requires an alternative sustainable solution. Recently, alkali -activated materials (AAMs), particularly originating from ground granulated blast -furnace slag (GGBFS), have emerged and presented sustainable alternatives due to their lower carbon footprint and better mechanical properties. The study focuses on its application to hybrid GGBFS activation utilizing NaOH, Na₂SiO₃, and alkali sulfates in a quest to develop high early strength self -compacting concrete (SCC). This study investigates the potential of SCC incorporating alkali -activated slag (AAS) around ۸۰% Silica Fume (SF) ۲۰% as a complete replacement for Portland cement. Before the test date, samples were prepared under standardized conditions and cured in a tank with limewater saturated at ۲۳±۱°C. Compressive strength tests were conducted on ۱۵۰ × ۳۰۰ mm cylindrical samples at ۱, ۷, and ۲۸ days. The findings indicate that SCC using AAS could arrive at an early -age compressive strength of around ۲۲ MPa at ۱-day age of curing. The hybrid activation system, powered by NaOH, Na₂SiO₃, and alkali sulfates, shows improvements in early -age strength and durability. This system offers a sustainable alternative to conventional cement, reducing CO₂ emissions while maintaining excellent mechanical properties.

کلیدواژه ها:

Self-compacting concrete (SCC) ، Early strength concrete ، Low carbon concrete ، Alkali -activated concrete ، Ground granulated blast furnace slag (GGBFS)