A study of the properties of alkali activated cement concrete with potassium carbonate activator

Alkali-activated cements (AAC) have recently attracted the vivid interest of the civil engineering industry as promising innovative alternatives to Portland Cement (PC) which is responsible for 8% of anthropogenic CO2 emissions. In this context, this paper studies concrete produced using potassium carbonate (K2CO3)-activated slag cements, on which there is paucity of information. A preliminary study included one-part versus two-part cements and different liquid/solid ratios. Following this, mechanical property and durability testing of the resulting concrete was performed for different curing conditions. The results indicated that strengths would be suitable for C20/25 concrete (i.e., suitable for domestic uses); these strengths were gained early in the curing process (already at 7 days) in most cases. However, by lowering the liquid/solid ratio of the mixes, higher 28-day strengths of up to C30/37 concrete were achieved. Ongoing work is investigating durability of this type of concrete with results so far showing good promise.