Reologia de pastas cimentícias contendo adições de minerais.

Abstract

Rheology of cement pastes containing mineral additions. Studying the rheological behavior of cement pastes containing mineral additions, is of great value for the various applications to used correctly. The behavior of mortars and concretes is directly related to the cement masses and the workability of these matrices is linked to the ease that the professional finds to handle them, thus, simulations are made of requests that such matrices may undergo during their mixing, transport and related application to understand the factors that stimulate the ability to work. The mineral additions in pastes and masses is increasingly widespread in the market due to chemical and mineral influences exerted on the fluid such as binder fineness, particle shape and origin. From the evolution of the rheometers, it is possible to study the rheological behavior of cementitious pastes through several tests, such as the flow test, thus measuring a shear stress, a determined shear rate and with a variation of these variables it is possible to use the rheological profile. In this work, the rheological study of different dosages of cementitious pastes prepared with Portland CP V-ARI cement, addition of three types of metakaolin and addition of ceramic ground brick residue was made. The pastes were analyzed for different percentages of cement replacement by minerals, with the water/binder ratio fixed at 0.5. You can provide measurements of rheological parameters such as shear stress, shear rate, hysteresis area, thixotropy and viscosity using a parallel plate rotational rheometer. The results obtained with the ground ceramic brick residue and type II metakaolin by 20% increase the initial yield stress when compared with the use of other metakaolin and the addition of minerals, in general, mainly at 10% and 15%, contributed to a better flowability of the masses that will be stored in a better handling.