Effect of Air-Entraining Agent on Rheology of Cement- Based Magnetorheological Pastes

Embedding magnetic particles into cement paste produces a smart material in which the rheological properties of the resultant paste can be actively controlled through the use of magnetorheological (MR) principles. This research investigates the rheological behavior of cement-based MR pastes with and without air entrainment to gain a better understanding of the effects of air-entrained bubbles on MR cement pastes. Such information would be critical for the use of such MR pastes in three-dimensional (3-D) concrete printing applications. It is revealed that the incorporation of entrained air increases the MR response, and this effect is related to the bubble-bridge effect. Keywords: air-entraining agent (AEA); magnetorheological (MR) paste; rheology; small-amplitude oscillatory shear (SAOS); smart material; storage modulus.