Flexural Characteristics of Fibre-Reinforced Alkali-Activated Composites

The need for environmentally friendly and high-performance composites for various construction and rehabilitation applications has resulted in the use of alternative binders and reinforcements. In this study, fibre-reinforced composites were made with lime-activated slag/fly ash as the binder and Polyvinyl alcohol (PVA) fibres as reinforcement. The fly ash was used as 0, 50, and 100% replacement of the slag and the corresponding performance of the composites evaluated in terms of the flexural and crack properties one year after they were made. The flexural properties evaluated are flexural strength, deflection and toughness. Image analysis was used to assess the crack properties and results presented in terms of the crack widths and areas. The findings from this study showed that alkali-activated binders can be utilized to produce fibre-reinforced composites for various construction and rehabilitation applications. It was also evident that the use of fly ash as a replacement of slag in the binder resulted in an increase in the ductility of the composites. However, higher content of slag resulted in higher flexural strength. Nonetheless, findings from this study showed that the content of fly ash used as a replacement of slag can be optimized depending on the performance required.