Improvement of rheological behaviour of cement pastes by incorporating metakaolin

Abstract

An experimental rheological investigation was conducted to evaluate the performance of Algerian metakaolin MK on cement pastes. In the present work, several rheological tests were carried out at 20°C, by using the stress controlled rheometer AR2000, on the fresh cement pastes incorporating 0%, 5%, 10%, 15% and 20% of MK. Effect of metakaolin on the rheological behaviour of cement pastes were discussed. Rheological parameters such as viscosity, compliance, loss and storage shear modulus are evaluated by means of rheological techniques of both flow and creep/recovery tests (static mode) and oscillatory test (dynamic mode). Shear moduli allow to give information on the evolution of the paste structure related to practically interesting problems such as workability. The results obtained have shown that MK improves the flowability and exhibits viscous rheological behaviour of cement pastes over elastic behaviour of control paste (0%MK). Moreover, the creep/recovery test show that the addition of MK exhibits a behaviour of viscoelastic liquid of cement pastes compared to a viscoelastic solid behaviour of control paste. The MK acts as filler and controls rheology