Environmental Engineering Reference
In-Depth Information
Table 2.
ciPW norm (weight %).
sample
eh-10
FV-19
FV-25
Gc-52
lZ-22
TF-32
TF-40
orthoclase
6.74
14.78
4.02
8.75
3.90
7.98
11.23
Quartz
1.37
-
albite
12.76
40.53
26.99
16.95
24.45
9.74
25.39
anorthite
16.32
15.37
20.15
16.04
22.01
15.73
20.22
nepheline
4.69
8.46
7.56
5.36
Diopside
27.70
10.05
18.76
20.18
18.14
26.72
15.41
hypersthene
0.86
12.23
18.44
olivine
10.42
1.02
5.45
11.55
14.91
5.44
Magnetite
9.50
5.67
7.16
7.25
6.74
8.26
6.89
ilmenite
9.93
5.18
4.61
7.17
4.52
7.03
6.61
apatite
1.73
2.75
0.95
1.68
0.71
1.92
2.53
Total
99.79
96.21
100.32
98.03
100.28
99.85
99.08
3.2
Rebound index by the Schmidt hammer test
Rebound index has been determined for samples of
vacuolar basalts. also, the equivalent compressive
strength was deduced from the schmidt hammer
test. These values must be considered estimates,
since this method of obtaining the compressive
strength is not the most suitable due to the high
margin of error involved.
The Table 4 reflects the values obtained by the
hammer for some of the basaltic samples and
its estimate equivalent in terms of compressive
strength.
Table 3.
Velocity of sonic waves (Vu).
sample
TF-4
TF-32
TF-39
TF-40
Vu (m/s)
3818.72
5235.52
3835.8
5551.78
sample
TF-41
TF-42
TF-48
lZ-7
Vu (m/s)
5768.15
5459.78
5338.55
2320.12
sample
lZ-9
lZ-19
lZ-21
lZ-22
Vu (m/s)
4245.4
2420.7
2874.63
2254.69
sample
lZ-9
lZ-19
lZ-21
lZ-22
Vu (m/s)
4245.4
2420.7
2874.63
2254.69
Table
4.
Rebound
index
and
equivalent
uniaxial
compressive strength.
equivalent
compressive
strength (MPa)
3.3
Resistance deduced from the point load test
in general, resistance is correlated with compres-
sive strength, by:
Rebound index
(average)
island (samples)
G. canaria (2)
25.5
16.8
Tenerife (4)
43.3
48.9
σ
c
=
K
⋅
I
S
where σ
c
= Uniaxial compressive strength (in MPa);
i
s
= Point load Test index; k = varies between 13
and 15 (Rodriguez-losada et al., 2007).
The Table 5 shows the values of PlT obtained
for some of the samples and the associated com-
pressive strength.
comparing the average values obtained here
with those obtained in the hammer test appreci-
able differences are observed. as already indicated,
this test is more reliable, thus the obtained values
are closer to the true ones.
lanzarote (4)
52.5
65.5
el hierro (2)
42.0
47.5
Fuertevent. (2)
49.5
59.5
Table 5. Point load test and equivalent uniaxial
compressive strength.
PlT (MPa)
(average)
equivalent compressive
strength (MPa)
island (samples)
lanzarote (5)
2.54
50.8
el hierro (2)
0.68
13.6
Fuerteventura (2)
5.00
100.0
3.4
Resistance determination from
the triaxial test
To get a more approximate estimate of the com-
pressive strength that can have this type of basaltic
on their characteristics (eg, the longitudinal velocity
is greatly reduced by the existence of cracks).
The average values of sonic velocities obtained
for basalt samples are shown in Table 3.
