| dc.description.abstract | The concrete self-compacting (CAA) was one of the greatest discoveries in concrete
technology in recent decades. To be considered self-compacting, three properties
must be achieved simultaneously: fluidity, cohesion and segregation resistance. The
CAA can be shaped in various ways, eliminates defects caused by failure of
concrete, as it has great ability to flow between the steel without segregation
themselves by releasing the external vibration compaction, which reduces the
manpower and accelerates construction. However, due to the high fluidity,
undesirable effects such as segregation of coarse aggregate and water mixture can
occur more easily. These effects can be controlled with the use of viscosity modifying
admixture or mineral admixtures, such as limestone fillers. This study will evaluate
comparatively the effectiveness of limestone fillers and viscosity modifying admixture
in control of segregation and exudation of folders and mortar concrete self-
compacting. Initially, there was a literature on the history, main properties and
characteristics, advantages and disadvantages, constituent materials and concrete
tests on self-compacting. The method of work was divided into three stages, first was
made the characterization of materials used in this study, in the second step, tests
were carried out scattering (mini-slump) and runoff (Marsh cone) into folders to
determine the point of superplasticizer saturation and to assess the influence of
limestone filler and viscosity modifying admixture in scattering and runoff of folders.
In the third step, tests were carried out in mortars to determine the influence of
limestone filler and viscosity modifying admixture in the spread and development of
mechanical strength. It was observed that both the limestone fillers as the viscosity
modifying admixture controlled exudation and segregation of the folders and mortar,
however, the viscosity modifier additive caused incorporation of air in mortar,
reducing the mechanical strength thereof. On the other hand, the limestone fillers
improved the packaging of the grains, resulting in increased mechanical strength. In
addition, the limestone fillers resulted in more homogeneous and cohesive pastes.
With respect to costs, the mortar with the addition of limestone fillers have the same
value (in R$/m³) that mortars with additive viscosity modifier. | |
