Civil Engineering Reference
In-Depth Information
Fig. 4.70 Sequence of accelerated ageing tests and compressive strength results before and after
ageing (Pacheco-Torgal and Jalali
2010
)
4.9 Other Waste Materials
Other waste materials have also been used as aggregates in concrete and cement
mortar production. The behaviour of these waste materials, which can be con-
sidered as industrial byproducts, will be discussed here.
4.9.1 Oil Palm Shell
The use of oil palm shell (OPS), an agricultural waste, created in palm oil pro-
ducing countries as coarse aggregates in structural lightweight concrete was
reported in detail (Basri et al.
1999
; Jumaat et al.
2009
; Mannan et al.
2006
;
Mannan and Ganapathy
2001a
,
b
,
2002
,
2004
; Teo et al.
2006
,
2007
,
2010
).
According to Mannan and Ganapathy (
2004
) concrete with OPS as coarse
aggregates can be used for several purposes such as road pavement, kerbs, con-
crete drains and flooring of buildings.
The workability of concrete with OPS as coarse aggregates was better than that
of conventional concrete, due to the smooth surface texture of OPS aggregates
(Basri et al.
1999
; Mannan and Ganapathy
2004
). The air content of concrete with
OPS aggregates was also higher than that of conventional concrete due to the
lower compaction of concrete with OPS aggregates. According to these authors,
the obstructions in compaction due to variations in shape of OPS aggregates as
well as the porous nature of OPS aggregates increased the air content of concrete.
The fresh and dry densities of OPS concrete were about 20 % lower than those of
conventional concrete and this mixes can be considered as structural lightweight
concrete (1450-1900 kg/m
3
) (Basri et al.
1999
; Mannan and Ganapathy
2004
).
Basri et al. (
1999
) observed that the compressive strength of OPS concrete was
about 40-55 % lower than that of conventional concrete, when both were cured in
three curing conditions. The highest compressive strength was seen in concrete
cured in standard moist curing conditions. The reduction in strength was mainly
due to the weaker crushing strength of OPS aggregates than that of NA. They
