Civil Engineering Reference
In-Depth Information
significantly the environmental impacts of construction by reducing the
space needed as landfill for waste disposal and reducing the demand for
raw materials through providing alternative sources of construction mate-
rials. As a result, the environmental impacts caused by the extraction of
nonrenewable materials, including extensive deforestation, top soil loss, air
pollution, and pollution of water reserves can be mitigated to some extent.
Recycling of C&D waste can also bring about economic and social benefits
related to the creation of new jobs. According to the 2002 report of the US
Environment Agency (EPA) the incineration or landfilling of 10,000 tonnes
of waste may create 1 job and 6 jobs, respectively, while recycling the same
amount of waste may create 36 jobs [6]. The market for recycled construc-
tion materials in Europe alone generated revenues of 744.1 million euros in
2010, and this is estimated to reach 1.3 million euros by 2016 [7]. It should
be noted that such high figures are conservative as they do not take into
account a nearly 100% C&D recycling scenario, which is deemed possible
in the near future.
Concrete wastes are one of the common components of the C&D waste
produced worldwide. Concrete is the most commonly used construction
material, and debris derived from demolished concrete structures con-
stitutes a considerable portion of the C&D waste generated worldwide.
Concrete waste has been reported to account for up to 40% of the total
C&D waste flux in some countries (Figure 4.1) [8,9].
The huge amount of concrete produced annually causes a number of
environmental concerns relating to
• The huge amount of the raw materials extracted and processed to
produce the concrete constituents, including aggregates, causing con-
cerns about depletion of nonrenewable natural resources
• The huge amount of energy used at different phases of the concrete
life cycle and the associated greenhouse gas emissions
• The huge amount of the waste generated during production and at the
end of the concrete service life (demolition wastes)
Various, 10%
Plastics, 5%
Wood, 10%
Concrete, 40%
Metal, 5%
Ceramics, 30%
Figure 4.1
Approximate composition of demolition waste in concrete buildings.
Search WWH ::
Custom Search