Enhancing reactivity and properties of fly-ash-based solid-form geopolymer via ball-milling Available to Purchase

This paper reports the synthesis of a solid-form geopolymer by ball-milling of raw materials of varying compositions together in the solid state. This resulted in the formation of ready-to-use geopolymeric precursors, which on ‘just the addition of water’ led to the development of solid-form geopolymeric binder with enhanced reactivity and properties. Conventional geopolymers are synthesized by using concentrated aqueous alkali solutions, which are corrosive and viscous, create problems during bulk handling and are not user-friendly. It was observed that the synergistic effect of the ball-milling of raw materials for 6 h resulted in a noticeable increase in compressive strength. The developed solid-form geopolymer was characterised by X-ray diffraction, Fourier transform infrared spectroscopy and field-emission scanning electron microscopy and evaluated for compressive strength. The solid-form geopolymer paste of 12·5 M concentration, cured at 60°C for 48 h, showed a compressive strength of 64 MPa after 28 d of testing, which is ∼20% higher than that of conventional geopolymers. The solid-form geopolymer offers improvements over conventional geopolymers with regard to the handling of alkaline activators and storage of feedstock.