Civil Engineering Reference
In-Depth Information
they observed similar compressive strength for concrete with marble aggregates
and reference concrete when the former mix was prepared with a superplasticizer.
4.9.11 Waste from Wood Sawing
The waste generated from sawing of wood can be used as lightweight aggregates
in the preparation of special types of concrete composites. Sales et al. (
2010
)
prepared lightweight composite aggregates by mixing sawdust and water treatment
sludge. The composite concrete prepared by using this composite aggregate had a
lower thermal conductivity by about 23 % than conventional concrete. The authors
proposed to use this concrete as non-structural sealing elements. Al Rim et al.
(
1999
) produced a clay-cement-wood composite using wood pieces with maxi-
mum size of 22 mm as aggregates. The incorporation of wood aggregate into
clayey concrete improved the thermal insulation and deformability behaviour but
reduced compressive strength. Several treatments methods were proposed by
Ledhem et al. (
2000
) to treat wood aggregate to improve the compressive strength
of wood with clayey concrete.
Becchio et al. (
2009
) reported that the use of waste generated from wood-
sawing industry as aggregates in concrete reduced the density and compressive
strength but significantly improved the thermal insulation of mineralised wood
concrete; furthermore, the compressive strength of this type of concrete was sig-
nificantly higher than that of commercial wood concrete. Turgut (
2007
) prepared a
composite brick using Portland cement, limestone powder waste and wood saw-
dust waste. The wood sawdust waste with different size fractions was used as
aggregates in this composite. The compressive strength, flexural strength, density,
ultrasonic pulse velocity and water absorption of the composite satisfied the rel-
evant international standards. The incorporation of high amounts of wood aggre-
gates with limestone powder increased the ductility of the resulting composite
brick. According to the author, the product could be used for several purposes such
as walls, wooden board substitute, an alternative to concrete blocks, ceiling panels,
sound barrier panels, and absorption materials.
4.10 Concluding Remarks
Several types of waste material generated from various industries are currently
used as aggregates in the preparation of concrete and cement mortar. The use of
waste materials in concrete as aggregates significantly changes the properties of
concrete.
The incorporation of ground plastics and shredded rubber can enhance some
specific properties of concrete such as toughness and post-cracking behaviour,
damping
behaviour,
thermophysical
behaviour,
which
have
several
technical
