Possibilities of Biomass Wood Ash Usage in Geopolymer Mixtures

Abstract

This paper presents the results of testing the physical and mechanical properties and durability of geopolymer mixtures. Fly ash was used as the basic binder, while its replacement was performed with wood biomass ash.The initial and final setting time were tested on the geopolymer paste, while flow value and bulk density were tested on the fresh mortar. Compressive and flexural strength and sulfate and freeze-thaw resistance were tested on hardened geopolymer mortar. Based on the most optimal results of mortar testing, the composition of concrete was determined, and slump, bulk density, compressive and flexural strength, penetration of water under pressure and sulfate and freeze-thaw resistance were tested. According to the results of compressive strength tests of geopolymer materials and concrete exposed to sulfate solution attack, the mixtures prepared with the addition of 20% wood biomass ash showed better sulfate resistance than the mixtures prepared only with fly ash.

Keywords

• biomass wood ash
• durability
• fly ash
• fresh and hardened properties
• geopolymer