Development of a measuring procedure of rheological behavior for self compacting concrete

Abstract

The objective of this study is to propose a rheological model for a self-compacting concrete (SCC) on a reduced scale in which a mobile (with 4 vanes) rotating at an imposed speed is immersed. This model allows to describe the rheological behaviour of concrete (at full scale) and to acquire its intrinsic parameters, namely the yield stress and the plastic viscosity. The validation of this approach is established first of all from the realization of six self-compacting concretes (at the real scale). The intrinsic rheological parameters given by their reduced concretes confirm their self plasticity by referring to the rheological results obtained with three other rheometers of international references. Indeed, a very good correlation is obtained between the slump flow of these six SCC and the yield stress of their reduced concretes. Moreover, a design of experiments with three variables is used to demonstrate that this approach is suitable for providing a mathematical model of the intrinsic rheological parameters (yield stress and viscosity) of SCC. The results showed that the yield stress is governed by the interactions (paste-superplasticizer) and (paste-aggregate) while the viscosity is exclusively governed by the paste.