Geoscience Reference
In-Depth Information
Table 7.2
Parameters for classifying fly ash (
after
Samsuri, 1997).
Properties
Fly ash class
F
C
SiO
2
+Al
2
O
3
+Fe
2
O
3
(min %)
70
50
SO
3
(max %)
5.0
5.0
Moisture content (max %)
3.0
3.0
Loss of ignition (max %)
6.0
6.0
Figure 7.15
Unconfined compressive strength for various types of stabilized fibrous samples with and
without fly ash.
trial mixtures of OPC treated with and without fly ash were tested for their UCS values.
Undisturbed, as well as 5, 15 and 30%OPC samples, with no additives, were tested as
control measure samples. The stabilized samples were mixed initially with the fibrous
peat (FPt) with natural moisture content
w
=
200% and air cured for three months.
The results are shown in Figure 7.15.
Four types of mixtures chosen for compaction test were fibrous peat with:
(a)
2.5% OPC and 2.5% FA
(b)
7.5% OPC and 7.5% FA
(c)
15% OPC and 15% FA
(d)
22.5% OPC and 22.5% FA
7.8.3 Silica fume/micro silica (SFU)
Silica fume or micro silica is an extremely fine product of high amorphous silica con-
tent arising from the condensation of rising vapour given off in the manufacture of
