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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 2
Study of the reuse of construction residues in concrete employed by blocks manufacture
found by researchers Boldrin et al. [1]; Lintz and Simonetta [21] for
these physical characteristics.
As for the compressive strength of the concrete specimens, com-
positions E1, E2 accounted for 94% and 58% of the value given for
the reference mixture (E0). For the other mixtures the fall for this
property was substantial.
For the tensile strength by diametrical compression, compositions
E0, E1 and E2 have values within the limits of resistance of con-
crete blocks.
As for the compressive strength of concrete blocks, the
NBR6136:2007 [22] classifies simple concrete blocks masonry,
into four classes, as shown in Table 2, being classified for use in:
Class A - With structural function, for use in masonry elements
above or below ground level;
Class B - With structural function, for use in masonry elements
above ground level;
Class C - With structural function ,for use in masonry elements
above ground level;
Class D - No structural function, for use in masonry elements
above ground level;
It can be observed that for all concrete mixes used in the manufac-
ture of the blocks the compressive strength values are within the
limitations of the Brazilian standard for use as part of the masonry.
The blocks executedwith themix concrete reference E0 and themix con-
crete E1, showed resistance above 6 MPa at 28 days, being classified
as “Class A” and the others meet the strength characteristics of “class B”.
Figure 7 – Results of average compressive
strength of concrete blocks at 14 days
Figure 8 – Results of average compressive
strength of concrete blocks at 28 days
Figure 9 – Test results of water absorption
by immersion of specimens
Figure 10 – Test results of water absorption
of concrete blocks
Table 2 – Requirements for characteristic
compression strength of
concrete blocks (NBR6136)
Class
Strength Feature (f ) MPa
bk
A
≥
6,0
B
≥
4,0
C
≥
3,0
D
≥
2,0