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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 4
B. F. TUTIKIAN | M. PACHECO
ABNT NBR 8802:1994 [11] specifies the execution of the propagation
velocity of the ultrasound wave procedure, which was chosen for being
a test which relies heavily on the compacity of the mixtures, identifying
the packaging among all components. The chloride ion penetration test
was chosen for being a representative for durability, regardless of its ap-
plication. This test was adapted from the ASTM 1202:2007 [12] norm.
Fig. 6 shows the tests performed in the hardened state.
3.4 Materials used
For the execution of the experimental work, the materials selected were
ones found in the state of Rio Grande do Sul (RS), which are economi-
cal and already used by the construction services for other purposes.
In order to determine the characteristics of the aggregates used
in the experimental work, the procedures adopted were in accor-
dance with the following standards: the specific mass tests of the
fine aggregates (regular sand and fine sand) were performed ac-
cording to ABNT NBR NM 52:2009 [13], while the specific mass
tests for the coarse aggregates followed ABNT NBR NM 53:2009
[14]. The unit mass tests were performed following ABNT NBR NM
45:2006 [15], and the granulometric composition analyses were
made according to the ABNT NBR NM 248:2003 [16] procedures.
3.4.1 Cement
The cement used was CPV-ARI (Portland cement with high initial
resistance). It was chosen because it is the most widely used in
the prefabricated building industry, which is one of the areas where
SCC can be employed with the most benefits. Table 5 shows its
chemical, physical and mechanical properties.
3.4.2 Aggregates
Two basalt gravel compositions were used as coarse aggregate.
Table 7 – characteristics of superplastizer additive
Technical datas
Function:
Superplastizer additive of third generation for concrete
Chemical base:
Polycarboxylic ether
Aspect:
Liquid
White cloudy
Seciundary action
Water reducer
Total water solubility
It does nor contein calcium chloride, intentionally added, or chloride-based ingredients.
Test
Specification
Unit
Appearance
White cloudy liquid
Visual
pH
5 – 7
-
Density
1,067 – 1,107
g/cm³
Solids
38,0 – 42,0
%
Viscosity
< 150
cps
Regular river sand was used as fine aggregate, and a non-pozzo-
lanic material was used as fine material, namely fine sand. This
aggregate is also used by some local companies, especially con-
creting service providers for conventional concrete (CC) compo-
sition and it may be stored outside in stalls which are relatively
easy to be built, without the need for great resources such in the
acquisition of a silo, for instance. All aggregates are commercially
available in the South of Brazil. Table 6 shows the characteristics
of the aggregates.
3.4.3 Superplastizer Additive
In order to dose the SCCs, a third generation superplasticizer ad-
mixture was used, one based on a chain of modified polycarbox-
ylic ether which acts as a dispersant for the cementitious material,
enabling superplastification and great water reduction, making the
concrete more workable without change in the setting time. The
characteristics are shown in Table 7.
3.4.4 Water
Water from the public water supply was used in the manufacturing
of the concretes, according to ABNT NBR 15900:2009 [17].
4. Results and Discussions
Table 1 shows the unit compositions obtained from the duties im-
posed by each method of dosage performed in the experimental
program.
The unit values to calculate the total SCC costs, shown in Table 1,
were quoted by suppliers in June 2011, when the basic unit cost
in Rio Grande do Sul (CUB - RS) for single-family homes was R$
868.99 while the dollar rate was R$ 1.73. The price found for the
ARI-RS cement was 0.44 R$/Kg. The sands cost 0.013 R$/Kg, the