Civil Engineering Reference
In-Depth Information
Table 2.16 Physical properties of fine and coarse lead slags along with natural aggregates
(Metwally et al.
2005
)
Property
Natural sand
Natural gravel
Fine lead slag
Coarse lead slag
Specific gravity
2.57
2.51
4.28
3.79
Density (kg/m
3
)
Loose
1,600
1,530
2,280
1,990
Dense
1,869
1,640
2,820
2,120
Voids (%)
Loose
38
39
47
47
Dense
27
35
34
44
Water absorption (%)
0.42
0.35
3.95
2.35
Fineness modulus
2.49
6.90
3.35
6.95
Crushing value (%)
-
13.5
-
29.3
Impact value (%)
-
6.82
-
13.4
Loss Angeles value (%)
-
16.7
-
47.0
The major minerals present in MBM-BA are hydroxylapatite Ca
5
(PO
4
)
3
(OH)
and whitlockite Ca
3
(PO
4
)
2
. Calcium hydroxylapatite is the major inorganic con-
stituent of bones and teeth. Trace amounts of some minerals such as quartz,
hematite and magnetite are also present in MBM-BA, which probably came from
other waste used as co-combustion materials. Although MBM-BA contains small
amounts of trace elements, the leachability of these meets the regulation set by
French Government for using in road construction.
Öztürk and Bayrakl (
2005
) investigated the possibilities of the use of tobacco waste,
a by-product in a cigarette factory as aggregate in lightweight concrete production.
The organic and water content in this aggregate are 66.21 and 25.45 % respectively.
Yellishetty et al. (
2008
) evaluated the recycling potential of four different iron
ore mineral wastes as aggregate in the preparation of concrete. The waste was
collected randomly, from different fresh waste dumps as recommended ASTM
D75; C702 sampling of aggregates. It was mixed to form a representative
homogeneous mixture. The sieve analyses of typical particle overburden material
from the waste dumps of the corresponding iron ore mines are presented in
Fig.
2.8
. A volume equivalent of approximately 50 % of the total is within the
usable range as aggregates for making of concrete cubes. Of the whole volume,
20 % is in the range of sand-silt-clay material. Variability in size distribution is an
indication of inherent geological properties of mine waste material and of the
crushing and compaction that waste undergoes while breaking/loosening.
Various physico-mechanical properties of the mine waste were measured
according to ASTM methods and presented in Table
2.18
. In aggregates from
different mines, the fineness modulus (FM) was within the range of IS2386
specifications prescribed for aggregate for civil constructions. Most of the physical
properties of the mine aggregates, belonging to different mines, were within ±5%
range of standard specifications and were in conformity with the concurrent Indian
Standards for aggregates.
