In Thailand, the main reason for steel reinforcement waste is
that some short unusable pieces are produced when core iron is
cut. This results from poor structural design and detailing. Many
problems related to poor material handling also result in waste
generation at construction sites. Deviations in the dimensions of
cast-in-place structural elements such as slabs, beams, and columns
are an important source of concrete waste. This arises due
to poor design of concrete formwork systems, and flaws in the
formwork assembling process. Some site managers also often order
additional amounts of concrete in order to avoid interruptions in
the concrete-pouring process. Sometimes this results in a surplus
of concrete that is not used. A combination of factors contributes
to the generation of waste from bricks and blocks. These are problems
related to material delivery, such as the lack of control in the
amount of bricks or blocks actually delivered and the damage of
bricks or blocks during the unloading operation. Thus, poor handling
and transportation could be said to be the major source of
waste for bricks and blocks. The main cause of tile wastage is quite
similar to those of blocks and bricks and, mainly arises because of
the need to resize them due to flaws in the integration of architectural
and structural design. Most often, the off-cut pieces are left as
debris (Chanchorn, 2002).