Aline Figueirêdo da Nóbrega de Azerêdo
Federal Institute of Education, Brazil
Title: Properties of lime-metakaolin pastes made of kaolin wastes: Rheological parameters
Biography
Biography: Aline Figueirêdo da Nóbrega de Azerêdo
Abstract
Metakaolin has been presented as very good pozzolanic material for using in lime mortars and cement mortars. Alternatively, many studies have shown that wastes, coming from the kaolin production, can produce good quality pozzolans. In Brazil, industries, that produces kaolin, generates a lot of wastes, which are not placed in adequate sites or reused. Many studies have discussed about the microstructural characteristics and hardened properties of pastes, mortars or concretes mixes. There are few studies about rheological properties of this kind of paste. In this work pastes containing only hydrated lime (LP) and metakaolin+hydrated lime (L-MK) (made of the kaolin production waste) were assessed in their fresh state. Rheological characteristics, like yield stress, viscosity (static rheology test), viscous and elastic modulus (dynamic rheology test), creep and recovery behavior were studied. The results showed that the curves of pastes presented as a non-Newtonian fluid following a Herschel Bulkely moldel. When the metakaolin was added to lime paste the yield stress and the viscosity was lower. From the dynamic tests it was obtained that the L-MK pastes were less rigid than LP. And according to the creep and recovery tests these pastes presented a curve model as a viscoeslastic liquid.