Setting, rheology and packing density of biomass fly ash/Portland cement mixtures

Abstract

Paper deals with rheological properties and packing density of fresh mixtures of Portland cement and biomass fly ash. Water demand of paste of normal consistency increases with increase of replacement level of biomass fly ash for Portland cement. Up to 5 wt. % contents of biomass fly ash yield stress and plastic viscosity values decrease, while at contents higher than 5 wt. %, the opposite trend was revealed. Biomass fly ash compared to Portland cement has proportionally lower content of particles with size of tens and first single digit numbers of microns. Deficiency in this region at higher contents of biomass fly ash in cement mixtures results in deflection from ideal packing density curve.