FlowCyl: one-parameter characterisation of matrix rheology

The FlowCyl is a simple flow viscometer – a modification of the Marsh Cone test apparatus developed to characterize cement pastes and grouts. The FlowCyl gives a one parameter characterisation of rheology called the flow resistance ratio or λQ for use in the Particle-Matrix concrete proportioning Model (PMM) as a description of the viscous phase of the concrete, while another parameter related to packing density is used to describe the particle phase. There have been numerous studies which have shown how the matrix λ Qvalues affect the rheological parameters of concretes with a given particle system. Recent studies have shown that the FlowCyl test, which has previously proven acceptable for the one-parameter characterisation of matrix phase rheology, is probably not suitable for matrices with high powder content and a superplasticiser dosage below the surface adsorption saturation. This paper reviews current studies that compare the measurements of the FlowCylwith the results obtained using a rheometer and presents initial results from a series of simulations of the FlowCyl test conducted to analyse the effect of yield shear stress (according to the Bingham model) on the measured flow resistance ratio λQ.