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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 4
B. F. TUTIKIAN | M. PACHECO
Following the completion of the compactness test, the next step
was to determine the water/cement ratio and the amount of super-
plasticizer admixture.
From that point on, unit composition I (1:4) was used to prepare
the adjustment mixture, so as to confirm the water/cement ratio
and, most importantly, determine the amount of superplasticizer
admixture experimentally. First an admixture value of 0.50% (con-
sidering the amount of solids and liquids in the admixture) was
defined, in relation to the cement mass and a water/cement ratio of
0.40. After determining those values, the intermediate mixture was
initiated, and from the tests performed in the fresh state, the final
ideal amount of superplasticizer admixture and the water/cement
ratio were defined.
From the results obtained, the final unit compositions for the SCCs
were determined without the need for substitutions. According to
the method, the ideal is to create four points so that the behavior
equations have a higher coefficient of determination, allowing the
curves to be better adjusted. The individual unit compositions are
shown in Table 1.
3.2 Tests performed in the fresh state
In the fresh state the SCC families were tested in order to assess
the flow properties, passing ability, resistance to segregation and
apparent plastic viscosity, following the technical specifications de-
fined by ABNT NBR 15823:2010 [4]. The tests included flow tests
(SF), draining time (VS), “L-box” (PL) and “V-funnel” (VF). Fig. 5
shows the tests in the fresh state being performed in the lab.
3.3 Tests performed in the hardened state
In order to compare the properties obtained in each SCC family in
the hardened state, the concretes were submitted to compressive
strength tests at 7, 28 and 91 days, modulus of elasticity at 91
days, propagation velocity of the ultrasound wave at 91 days, and
chloride ion penetration at 28 days.
The compressive strength test, performed in compliance with ABNT
NBR 5739:2007 [7], was carried out because that is the most com-
monly used property in research and in real applications, as well as the
Figure 5 – Tests carried out in the fresh state
Figure 6 – Tests carried out in the hardened state