Abstract
•Highlights the effect of long-term curing on physico-mechanical properties.•Effect of replacement of primary precursor with secondary precursor.•Porosity and water absorption of geopolymer blocks.
Geopolymer has played an important role in the development of environment friendly building material using waste from various industries, agriculture and municipal waste. Most of the waste obtained from various industries are pozzolanic in nature or can be made reactive upon processing. Thus, are easy to incorporate in the mix design to achieve desired physical and mechanical properties. However, in practical scenario the total cost of the building materials is controlled by incorporating non-reactive materials as fillers. Considering this, an experimental investigation is carried out to develop with an objective to develop thermally efficient geopolymer block containing a fixed amount of crusher dust as filler and fly ash as the primary precursor and either rice husk ash or bottom ash as partial replacement of fly ash (i.e., 20, 30 and 40 % of fly ash). A combination of sodium silicate and sodium hydroxide mixed in the ratio of 2.5 was used as the alkaline solution and are cured at a constant temperature of 60 °C. The obtained results show that the developed geopolymer has lower thermal conductivity as compared to the traditional bricks and has lower water absorption and porosity values. The compressive and flexural strength are found to be greater than the strength requirement of first-class bricks.