Environmental Engineering Reference
In-Depth Information
Table 4. Physical test for the aeV 0-12 mm and aeV
0-8 mm fraction.
Table
6.
Mechanical
characteristics
of
the
aPn
0-5 mm.
Physical test
Units
0-12 mm
0-8 mm
Mechanical properties
Units
Value
specific gravity
g/cm 3
2.6
2.6
compressive strength (7 days)
n/mm 2
3.3
Bulk density
kg/dm 3
963
894
compressive strength (28 days)
n/mm 2
7.6
compressive strength (90 days)
n/mm 2
10.1
compressive strength (180 days)
n/mm 2
10.9
Table 5. chemical composition of the
aPn 0-5 mm.
Table 7.
Physics characteristics of the aPe 0-6 mm.
chemical composition (%)
Value
Physical properties
Units
Value
sio 2
56.12
0.05
λ Thermic conductivity
W/m ⋅k
al 2 o 3
16.54
ignition less
%
<2
Fe 2 o 3
4.99
Balance of moisture
mm
1.5
cao
2.61
specific gravity
g/cm 3
2.2
Mgo
1.11
Bulk density
kg/dm 3
90 ± 20%Vol
so 3
0.2
Ph
7
P.F.
7.2
Fire reaction
class
a1
R.i.
50.57
Reactive sio 2
32.8
Table 8. chemical composition of the
aPe 0-6 mm.
particles fit within the interval of 2-64 mm, and
the rest are minor particles. For this experimen-
tal study Vsa in the 0-12 mm and 0-8 mm size
fractions were used. Granular tests were made in
accordance with Une-en 933-1 and Une en
933-2:1996 regulations. Table 4 shows the results
of the density tests for both kinds of fractions.
chemical composition (%)
Value
sio 2
74,0 ± 2,0
al 2 o 3
13,0 ± 1,5
Fe 2 o 3
1,0 ± 0,3
cao
1,4 ± 0,4
Mgo
0,6 ± 0,3
k 2 o
3,5 ± 1,5
2.1.6 Natural pozzolanic aggregate
(APN 0-5 mm)
natural pozzolanic aggregate (aPn) is a type of
aluminosilicate mineral containing large quantities
of reactive sio 2 and al 2 o 3 . it is widely used in the
cement industry in the canary islands as an active
cement admixture. The properties of pozzolan
materials depend on their chemical composition
and internal structure. normally these materials
do not have blending properties by themselves, but
when mixed in finer sizes with lime or cement and
in presence of water, the active oxides will gradually
have a secondary reaction with ca(oh) and will
form basic calcium hydrosilicates in the blended
paste, as well as the so-called pozzolanic reaction,
forming low basic calcium hydrosilicates. as a
result, there will be an increase not only in the qual-
ity of the hydrates but in the quantity as well, and
the strength of the cement paste and other proper-
ties can be greatly improved (Xincheng Pu. 1999).
in this study aPn 0-5 mm size fraction from
arguineguin (Gran canaria) was used. The physi-
cal properties of aPn can be summarized in two
parameters: the relative density of 2.35 gr/cm 3 and
the high moisture content of 13-16%. it is a rather
weak rock, with a low compressive strength of
about 40 kp/cm 2 . Tables 5 and 6 show the chemical
na 2 o
4,5 ± 1,0
h 2 o combined
<3
and mechanical properties of aPn used in this
study. The granular tests were made in accordance
with Une-en 933-1 and Une en 933-2:1996
regulations.
2.1.7 Expanded perlite aggregate (APE 0-6 mm)
Perlite is a siliceous volcanic rock. Upon rapid
heating, above 871°c, this aggregate transforms
into a low-density cellular material increasing up
to twenty times its original volume. This expan-
sion is due to the 2-6% of water in the natural
perlite aggregate. This material is referred to as
expanded perlite. expanded perlite aggregate
(aPe) is defined as a light granular thermal insula-
tion material, with a white or grayish colour The
physical and mechanical properties of 0-6 mm
aPe used in this experimental study are shown
in Table 7 and in Table 8. The spanish concrete
structural Regulations (ehe-08) recommend
that the density for each granular fraction and its
corresponding volume should be determined, and
they also exempt aPe from fulfilling water absorp-
tion limits.
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