Stabilisation of clay with fly-ash geopolymer incorporating GGBFS

Abstract

Low water/binder ratio and higher activator content can help to accelerate the setting and strength development of fly-ash geopolymers cured at ambient condition. This study aims to achieve clay stabilization with fly-ash based geopolymer incorporating ground granulated blast-furnace slag (GGBFS), to enhance soil strength performance at ambient temperature. Laboratory experiments were performed on clay samples stabilized with both slag and fly-ash geopolymer and ordinary Portland cement (OPC), including the soil plasticity, compaction and unconfined compressive strength. The investigation was expanded to include un-activated fly-ash/slag clay samples used as control mixtures. The results indicated that introducing GGBFS to class (F) fly-ash based geopolymer assists, when synthesised in certain concentrations, in achieving a setting time and compressive strength comparable to OPC stabilised clay.