Physical and Mechanical Properties of Geopolymer Synthesized from Alternate Source Laterite

Abstract

Procurement and development of materials are essential facts of structural engineering practice. This study seeks to understand potential of laterite deposit in Ado-Ekiti metropolis for development as source material for geopolymer for engineering applications. Scooped laterite from alternate sources of Ekiti Parapo Pavilion and Federal Polytechnic Gate deposits were calcined at 750°c thereafter pulverized. The metallic oxide of the pulverized samples were determined. Alkaline activator solution of NaOH and NaSi03 while maintaining NaoH at 8M, with sodium hydroxide - sodium silicate- sterile water ratio of 7:3:3. The alkaline activator with the source material at ratio of 0.45 mixed was used to produce 50×50×50mm³ specimen cubes based on the alternate geopolymer source materials. Sets of the specimen were cured respectively at 27°C (room temperature), oven temperature 50°C and 90°C respectively for 28days, 72hours and 72hours. To evaluate physical and mechanical properties of the specimens, density, porosity and comprehensive strength of the specimens were determined. Result shows that the specimen density decreases with increase of cure temperature while porosity increases with increase cure temperature. Specimen density ranges from 2.16g/cm³-2.4g/cm³ and Porosity ranges from 8.8%-17.64%. Specimen comprehensive strength increases with cure temperature with strength value ranges from 1.74N/mm³-7.24N/mm³ for geopolymer based on Ekiti parapo laterite. The trend for density, porosity and comprehensive strength for the specimen were similar for geopolymer based on the Polytechnic Gate laterite except that the comprehensive strength were relatively lower with minimum value ranges from 0.58N/mm³- 3.80N/mm³.