Pond ash–kaolinite–fibre-based geopolymers: processing and strength assessment

Abstract

Utilisation of fly/pond ash has been a great concern across the world over the last two and half decades. Therefore, a need arose to evolve an effective and sustainable procedure to utilise such hazardous waste material. This work explores the judicious addition of fibre and kaolinite in pond ash-based geopolymers. The shear strength parameters, peak deviatoric stress, stress–strain relationships and microstructure of such geopolymers were investigated and reported. In this study, the geopolymer paste was cast in a mould and an unconsolidated undrained triaxial test was performed on the sample. Pond ash- and pond ash–kaolinite-based geopolymers are found to exhibit excellent strength. It is observed that the strength of geopolymers increases with increase in the level of kaolinite. It is additionally observed that an addition of fibres enhances the ductility and strength of simple pond ash-based geopolymers, whereas with an increase in the kaolinite level, the impact of fibres on the strength of pond ash–kaolinite-based geopolymers becomes negligible.