The density-morphology relation: Rice husk filled fly ash geopolymer brick

Undeniable need of an alternative material for Ordinary Portland Cement has led to major focus of geopolymer source materials. Production of one ton of cement emits 0.87 ton of carbon dioxide (CO2), The use of new sources materials such as fly ash a have potential as geopolymer bricks plus can reduce the emission of carbon dioxide by ordinary Portland bricks which cause the environmental impact to the global. First part of this work is to determine the feasibility of using rice husk as a reinforcing material for fly ash geopolymer brick. Mix design of 2:5 Na2SiO3/NaOH ratio, 12 M NaOH concentration and solid-to-liquid ratio of 2.0 with varying rice husk loading was tested and cured at room temperature then at 70°C for 24 hours to get stable early strength. The microstructure of fly ash geopolymer brick with rice husk ash were analysed for raw material (fly ash and rice husk ash) and geopolymer brick product. From morphology analysis, almost all particles has took part in geopolymerization process and compacted area has represent the form of geopolymer gel through microstructure analysis that has carried out both fly ash and rice husk ash in geopolymer brick. The best mix design also correlate with highest result obtained density analysis.