Sustainable Geopolymer Pavers: A Comparative study of Rice Husk Ash and GGBS based mixes

Sustainable material sources are used in the development of geopolymer pavers to minimise their impact on the environment. Nine sets of geopolymer (GP) mixes of fly ash, ground granulated blast furnace slag (GGBS), and rice husk ash (RHA) were developed for this study in order to examine their effects on GP. A 12M concentration of sodium hydroxide and a 1:2 ratio of sodium silicate to sodium hydroxide were utilised to maintain the alkaline binder ratio at 0.45. The mechanical and water-absorbing qualities of the GP pavers were assessed after a 28-day curing period. The results show that, due to its increased porosity and decreased pozzolanic reactivity, adding more RHA to geopolymer pavers causes them to absorb more water and have lower compressive and tensile strengths. By contrast, GGBS significantly improves mechanical and durability properties; strength rises to 54 N/mm2 and water absorption falls to 0.6% following 100% replacement. The high concentration of calcium in GGBS promotes rapid geopolymerization and thick C-A-S-H gel formation.