Page 57 - Riem-Vol6_nº3

402 IBRACON Structures and Materials Journal • 2013 • vol. 6 • nº 3
Study of the influential factors on the rheological behavior of adhesive mortar available in the market
sented by grains larger than 0.075 mm. Table 3 reflects the per-
centages retained and passed through the sieves with openings
of 0.075, 0.15, 0.3 and 0.6 mm.
It is possible to verify that there are considerable differences in the
percentages retained in each sieve when compared to different
mortars in sieves with openings of over 0.075 mm (coarse frac-
tion). The fine fraction, in turn, showed a similar distribution, with-
out significant differences between them, the only exception being
Sample D which differed from the others by at least 5%.
Table 4 reflects the morphological results of particles retained in
the sieve openings of 0.15, 0.30 and 0.60 mm and their coefficients
of roundness and the elongation of the grains. Table 5 reflects the
bulk density results in the anhydrous and fresh mortar states along
Figure 2 reflects a diverse particle distribution in the mortars and
Figure 3 illustrates a specific particle size distribution of fine frac-
tion (particles smaller than 75 μm).
By analyzing the profile of the size distribution curves of the
mortar (Figure 2),mortars A, C and D had narrow distribu-
tions, which tends to reduce the mean distance of separation
between the particles, influencing the rheological behavior of
the adhesive mortar. Opened distribution increases the flow
benefits, since the smaller grains are more separated from the
larger grains, thereby reducing the friction between them. From
the data obtained from the sieve analysis, it can be stated that
the mortar adhesives have their greatest variations when the
particle size distribution is in the range 100 a 1000 µm, repre-
Table 2 – Reconstitution of the aproximation formulation of adhesive mortars
Adhesive mortar
A B C D E F
Aggregate (%)
Cement (%)
Limestone filler (%)
Moisture (%)
74.75
15.86
9.39
0.13
75.80
20.70
3.50
0.10
74.67
17.77
7.55
0.16
70.67
17.90
11.44
0.15
80.27
17.86
1.87
0.16
74.31
19.52
6.17
0.15
Figure 2 – Particle size distribution
of adhesive mortars
Figure 3 – Particle size distribution for particles
finer than 75 µm
Table 3 – Percent of material retained and Percent of material pass on sieve
Adhesive mortar Sieve
A mm mesh B C D E F
% fine fraction
(passing the sieve)
% fine fraction
(retained in the sieve)
21.8
31.2
42.2
4.3
0.5
0.075
0.075
0.15
0.30
0.60
200
200
100
50
30
20.9
12.7
35.8
28.1
2.5
22.8
12.2
47.0
13.0
5.0
27.2
15.6
51.2
5.4
0.6
19.4
31.8
24.8
22.9
1.1
21.8
9.5
33.1
32.8
2.8