Print version ISSN 0366-6913
CASTRO, A. L. de; LIBORIO, J. B. L. and PANDOLFELLI, V. C.. Review article: rheology of high performance concretes applied in building site. Cerâmica [online]. 2011, vol.57, n.341, pp.63-75. ISSN 0366-6913. http://dx.doi.org/10.1590/S0366-69132011000100009.
From a rheological point of view, concrete can be understood as a concentrate suspension of solid particles (aggregates) in a viscous liquid (cement paste). In such case, its fresh behavior should be evaluated based on the concepts of rheology, the science which relates the deformation and flow of a fluid under stress influence. Several studies had already been accomplished along the time, resulting in a series of equations that describe the fresh concrete behavior. It is known that the rheological behavior of this material is close to that of a Bingham fluid and two rheological parameters are required for its description: yield stress and plastic viscosity. The rheology of fresh concrete has been studied by measurements that vary among simple and practical test methods, such as the slump test, and more sophisticated equipments that determine the flow curve of the material, such as the rheometer. Therefore, it is possible to attain a correlation between shear stress and shear rate under conditions defined physically. As fresh concrete is a heterogeneous material, a more accurate approach of its rheological behavior is given by the direct analysis of the forces (torque) that result from the shear (rotation speed) of the concrete. Thus, this paper presents a review concerning the main concepts related with the rheology of high performance concretes applied in building site, which involves the rheological characterization and the test methods used for the measurement of the rheological properties.
Keywords : rheology; yield stress; plastic viscosity; high performance concrete.