Abstract:
Researchers have become interested in cutting-edge geopolymer technology and the creation of
geopolymer composites as a means of achieving sustainability in the production of concrete. In
this study, the feasibility of using diatomaceous earth from Nakuru, Kenya, as a source for
geopolymer concrete was evaluated. The chemical and physical analysis of diatomaceous earth
were carried out using standard techniques. Thermogravimetric (TGA) and Differential Scanning
Calorimetry (DSC) analyses were performed on the diatomite for thermal characterization. The
Sodium silicate/Sodium hydroxide alkaline activated diatomite-based brick specimens were
moulded, and their mechanical and physical features were determined using standard test
procedures. The diatomaceous earth’s chemical composition showed that silica (SiO2) was the
predominant component, with 88.12%. Calcium oxide (CaO) was 4.26% and alumina (Al2O3) was
4.25%. There were also trace levels of other oxides such as MgO, K2O, TiO2, MnO, Fe2O3, and
P205. The thermogravimetric analysis showed a loss on ignition of 5.68 % and that its softening
point is higher than 950 °C. The particle size analysis and the Atterberg limit test showed that the
diatomaceous earth from Nakuru, Kenya, is a cohesive and medium plastic silt, with an average
particle size of less than 50.4 μm. The diatomite-based specimens had an average compressive
strength of 22.98 MPa, a density of 1.38 g/cm3 and water absorption of 9.32 %. The chemical
composition suggests that it is comparable to Class F pozzolan. The mechanical, physical and
durability performance falls within the acceptable limits provided in literature. This research
showed that Kenyan diatomite can be successfully employed as a silica source in geopolymer
formulations, providing hopeful approaches to utilizing and recycling the resource
