Particle-size distribution, fineness, and morphology of powders used in flowable concrete greatly affect their rheological properties. An experimental investigation was undertaken to determine the physical characteristics of dry cementitious binders using Carr measurements and evaluate their coupled effects on rheology of cement-based suspensions. Cement, glass pozzolans, limestone filler, fly ash-F, and ground granulated blast-furnace slag were investigated. The angles of repose, fall, and spatula, compressibility, and cohesion were measured. The experimental results showed that dry flowability of blended systems are correlated to their particle-size distribution, Blaine specific surface area, morphological characteristics, packing density, specific gravity, and cohesion. The mean average diameter, fineness, and morphological properties showed the most significant effects on dry flowability of the investigated dry powders. On the other hand, the yield stress and plastic viscosity values of the suspensions were found in good agreements with the Carr's angles and dispersion indicators of the investigated systems. (C) 2020 Elsevier B.V. All rights reserved.