Civil Engineering Reference
In-Depth Information
applications. The incorporation of rubber and plastic wastes and CBA, waste from
wood sawing and some ceramic waste as aggregates can reduce the density of
concrete and therefore these wastes can be used to produce lightweight concrete.
On the other hand, several industrial wastes such as the majority of non-ferrous
slags and some ferrous slags that have significantly higher bulk density than that of
NA can be used as aggregates in the production of heavyweight concrete. CBA
and some ceramic wastes can absorb high amounts of water and therefore they are
used as aggregates for internal curing of concrete. FA generated from coal fired
powered plant can beneficially be used as fine aggregates in concrete and cement
mortar preparation, which can increase the consumption volume of these materials
in the construction sector.
The incorporation of rubber and plastic wastes as well as some ceramic
aggregates deteriorates the mechanical properties of the resulting concrete. On the
other hand, the addition of some ferrous slags causes the expansion of concrete due
to the presence of deleterious constituents in these slags, like free lime and
magnesia. Therefore, treatments of these wastes before application or some
innovation during the production of concrete and cement mortar are occasionally
necessary to overcome these problems. The presence of toxic elements in some
industrial wastes such as coal ash, some mining industries wastes and the majority
of slags will increase the concentrations of these elements in cement mortar and
concrete with these waste aggregates. Therefore, the fate and leachability of toxic
elements from waste with cement mortar and concrete are important aspects that
need to be considered for proper use of these wastes in constructions.
Some other solid waste materials generated from various industries such as
mining, shoe, tobacco production, food and metal processing, pulp and paper
mills, marble processing and waste sludge generated from processes such as
contaminated water treatment, petroleum exploration are also reported as aggre-
gates in various types of concrete production. The use of industrial wastes as
aggregates in concrete has the potential to consume a vast amount of waste
materials since aggregates are the major constituent of concrete and cement
mortar. The use of waste materials in construction can solve most of the problems
associated with their disposal as well as save natural resources related to aggre-
gates mining. Therefore, the production of cheaper and more durable concrete
using these waste aggregates can solve to some extent the ecological and envi-
ronmental problems. However, the lack of widespread reliable data on the use of
the majority of waste materials as aggregates in cement mortar and concrete can
hinder their use in construction industry. Therefore, more research is required to
design consistent and durable concrete with such waste aggregates.
References
Aggarwal P, Aggarwal Y, Gupta SM (2007) Effect of bottom ash as replacement of fine
aggregates in concrete. Asian J Civil Eng (Build Hous) 8(1):49-62
