Experimental investigation of geopolymer concrete along with biomedical and bone China waste at different molarities of sodium hydroxide

In this study, geopolymer concrete (GPC) is prepared using fly ash as source material along with alkaline activators (sodium hydroxide + sodium silicate) for sustainable development. There are three different sodium hydroxide molarities: 8, 12, and 16 utilised. Incinerated biomedical waste ash (BMW) and bone China waste (BCW) are substituted for the fine aggregates in GPC at varying ratios of 10, 20, 30, 40, and 50%. The utilisation of wastes in place of fine aggregates in GPC are helpful in solving the dumping problem of wastes, saving energy, and natural resources (sand quarries). The results showed that, relative to the control mix, the density, workability, and strength increased up to 60% replacement of sand by 30% BMW and 30% BCW and beyond this, the strength and other properties decreased. In contrast to the combination of 50% BMW and 0% BCW, the mix with 50% BCW and 0% BMW demonstrated great strength. In terms of molarity, the mixes with 16 M sodium hydroxide concentration showed higher workability, density, strength and lower air content as compared to the mixes with 8 M and 12 M sodium hydroxide concentration.