Effect of fly ash on rheology of blended cement paste

Concrete is mostly widely used construction material today. Other than its hardened properties, its behavior in green state affects the constructability and economics to a great extent. Modern concrete uses various supplementary cementitious materials, either as replacement of cement or as additive to enhance behaviour of concrete, both in hardened state and in green state, to improve its structural behaviour along with its economics and sustainability in green state, concrete needs enough consistency to be transported, placed, consolidated and finished in structural forms. The property of concrete in green state which controls its ease in transportation, placement, consolidation and finishing depends on rheology of material. The rheology of concrete, not only affect the cost, but also affects structural and durability behavior of resulting structure in the longer run. Other than aggregate mass, paste rheology principally affects the rheology of concrete. The paper investigates the effect of fly ash, most commonly used supplementary cementious material, as cement replacement on blended paste rheology. It examines the influence of three variables of fly ash, fineness, replacement levels, and waterbinder ratio on the yield stress and viscosity of blended pastes. © 2019 Associated Cement Companies Ltd.. All rights reserved.