Textile-cellulose as a secondary modifier in graphene and SCM-based cement paste

To address the principle of circular construction, this study analyses the effect of cellulose extracted from textile waste on the properties of blended cementitious paste specimens. Despite existing cellulose research, multi-component systems combining cellulose with other modifiers remain unexplored. The investigation explores compressive strength behaviour when cement is partially substituted with cellulose (0-5%) in three composite systems containing graphene oxide (GO), fly ash (FA) and ground granulated blast furnace slag (S). Chemical and microstructural analytical techniques were employed to examine the reaction kinetics of paste samples. Analysis showed that the recycled textile cellulose played a crucial role in modifying cement paste hydration and the properties of the composite. Optimal compressive strength enhancement was observed with 1% cellulose incorporation for all composites. Specimens with 0.03% GO addition achieved a 10.1% increase in strength at 28 days. FA composites demonstrated enhanced early-age properties with a 13.8% increase in strength at 7 days, maintaining an 11.0% improvement at 28 days. Slag-based composites demonstrated increased hydration with a maximum 28 day-strength increase of 9.6%. Cellulose acts as an internal curing agent regardless of the presence of GO, FA, or S, enhancing hydration near to the cellulose interface. However, higher concentrations of cellulose result in cluster formation, leading to more microcracks and micropores. The findings indicate that cellulose dosage optimization in blended composites can advance both environmental sustainability and mechanical performance. • 10% strength improvement with 1% cellulose in GO-added composites • Cellulose accelerates the pozzolanic reaction of fly ash with a 14% strength gain • 83% of hydration observed with 5% cellulose in slag composite • Water retained by cellulose promotes internal curing in cement paste • Excessive cellulose creates clusters, weakening the composite through microcracks