Civil Engineering Reference
In-Depth Information
Other factors that greatly affect the selection of building materials are their
costs and social requirements such as thermal comfort, good mechanical properties
(strength and durability), aesthetic characteristics, health effect and the ability to
build quickly. For example, the use of some building materials such as paints,
treated wood or foams can have a toxic effect on the occupants of a building and
therefore should be considered carefully. Ideally, the combination of all envi-
ronmental, economic and social factors can give a clear description of a material
and thus helps in a decision-making process regarding the selection of the mate-
rials suitable for buildings (Abeysundara et al.
2009
). According to Calkins (
2009
),
the materials that reduce the use of resources, minimise environmental impacts,
pose no or low human health risks during their handling and service life, assist
with sustainable site design strategies can be considered as sustainable construc-
tion materials.
Several codes and policies have been developed for environmentally efficient,
carbon neutral, eco-designed building constructions. For example, the European
commission developed a policy that takes into consideration the whole life cycle
of the product, comprising three main phases: environmental impact of the
products, environmental improvement of the products and policy implications.
However, several problems still exist in addressing the issues related to sustain-
ability in construction such as lack of innovation or inadequate level of skills. In
the following section, sustainability in concrete production, the major construction
material, will be briefly highlighted.
1.3 Sustainability in Concrete Production
Concrete is the major construction material and plays a vital rule in the devel-
opment of current civilisation. It is the most used man-made material in the world
since its invention. Worldwide, about three tonnes of concrete are used annually
per person (Cement Concrete Aggregate Australia no date). The consumption of
concrete as construction material in the world is over twice the total consumption
of all other building materials including wood, steel, plastic and aluminium. It is
reported that the total annual concrete production in the world is more than
10 billion tonnes (Meyer
2009
). More than 0.9, 5 and 0.6 billion tonnes of Portland
cement, aggregate and potable water, respectively, are necessary for the produc-
tion of such an amount of concrete. The massive use of concrete as a construction
material is due to its versatile properties. Properties such as strength, durability,
affordability and abundance of raw materials make concrete the first choice
material for most construction purposes. However, concrete production has several
negative impacts on the environment, such as the emission of CO
2
and other
greenhouse gases and the use of non-renewable natural resources like natural stone
and water, and therefore a lot of attention has been paid recently to tackling the
environmental issues related to their use in concrete preparation.
