When designing a building, an architect plans for
spatial, environmental and visual requirements. Once
these requirements are satisfied, it is necessary to detail
the fabric of the building. The choice of materials and
the manner in which they are put together to form
building elements, such as the foundation, walls, floor
and roof, depend largely upon their properties relative
to environmental requirements and their strength.
The process of building construction thus involves
an understanding of: the nature and characteristics of
a number of materials; the methods to process them
and form them into building units and components;
structural principles; stability and behaviour under
load; building production operations; and building
economics.
The limited number of materials available in the
rural areas of Africa has resulted in a limited number of
structural forms and methods of construction. Different
socio-economic conditions and cultural beliefs are
reflected in varying local building traditions. While
knowledge of the indigenous building technology
is widespread, farmers and their families normally
can erect a building using traditional materials and
methods without the assistance of skilled or specialized
craftsmen. However, population growth and external
influences are gradually changing people’s lives and
agricultural practices, while some traditional materials
are becoming scarce.
Hence, a better understanding of traditional materials
and methods is needed to allow them to be used more
efficiently and effectively. While complete understanding
of the indigenous technology will enable architects
to design and detail good but cheap buildings, new
materials with differing properties may need to be
introduced to complement the older ones and allow for
new structural forms to develop.
Loads on building components
Loads are usually divided into the following categories:
Dead loads, which result from the mass of all the
elements of the building, including footings, foundation,
walls, suspended floors, frame and roof. These loads are
permanent, fixed and relatively easy to calculate.
Live loads, which result from the mass of animals,
people, equipment and stored products. Although the mass of these loads can be calculated readily, the fact
that the number or amount of components may vary
considerably from time to time makes live loads more
difficult to estimate than dead loads. Live loads also
include the forces resulting from natural phenomena,
such as wind, earthquakes and snow.
Where wind velocities have been recorded, the
following equation can be used to determine the expected
pressures on building walls:
0 comments :