Engineered cementitious composite with nanocellulose and high-volume fly ash

This research develops a sustainable Engineered Cementitious Composites (ECC) with reduced cement usage by incorporating high volume fly ash (HVFA) and silica fume, along with the novel application of nanocellulose (NC)- a plant-based nanomaterial- and hybrid fibres to achieve high strength and ductility simultaneously. 12 mixes were developed including three base ECC mixes with 1.5 % polyethylene (PE) and 0.5 % steel fibres with varying proportions of fly ash and silica fume (1.2:0-1:0.2) and nine NC reinforced ECC mixes with varying dosages of NC (0.15 %, 0.2 %, 0.25 % by weight). The effect of fly ash/silica fume ratio and NC on mechanical properties was investigated through compressive and uniaxial tensile tests. Scanning electron microscope (SEM) and differential scanning calorimetry (DSC) techniques were utilized to gain insights into the HVFA and NC matrix systems as well as the mechanisms of NC and hybrid fibres. Results showed that reducing the fly ash/ silica fume ratio increased strength but reduced tensile strain. Incorporating NC improved strength across all mixes, irrespective of fly ash/silica fume content, with the mix containing 0.2 % NC showing the highest improvement. This novel ECC is anticipated to offer a sustainable and high-performance material solution for engineering structures.