Evaluation of mechanical, durability and sustainability performance of geopolymer concrete using sodium silicate waste as source material

Abstract

This study examines the physical, mechanical, and durability characteristics of geopolymer concrete (GPC) when blended with sodium silicate waste (SSW). SSW was added in varying amounts from 0 % to 50 %. The concrete was exposed to sulfuric acid and nitric acid (both at 2 % concentration) over 360-d, with assessments every 28-d to observe long-term performance in acidic and marine environments. The concrete's workability decreased by 35 % when 50 % SSW was added, making it stiffer. Compressive strength increased by 18 % with 50 % SSW, indicating enhanced polymerization. After 360-d, mass loss was minimal (2 % with sulfuric acid, 2 % with nitric acid), while strength loss ranged between 35 % and 37 %. In marine environments (sodium chloride (NaCl) & magnesium sulfate (MgSO4), the observed mass loss after 28-d was about 1 %, and strength loss was slightly lower with 50 % SSW (38 %) compared to GPC without SSW (39 %). Using SSW, the cost efficiency improved by 21.71 % and energy efficiency improved by 18.56 % compared to concrete without SSW. The study concludes that SSW can be a reliable and sustainable alternative in GPC, offering enhanced performance and cost-efficiency.

Keywords

• FA
• SSW
• Alkaline solution
• Concrete
• Circular economy
• Waste management