Civil Engineering Reference
In-Depth Information
Table 8.3:
Primary energy consumption during poduction
Raw materials/base products
MJ/kg
Production
temperature (°C)
Sand and gravel
0.1
-
Earth for building, when compressed
0.1
-
High-fired clay
3.5
1050-1300
Well-fired clay
3.0
800-1050
Medium-fired clay
2.5
500-800
Low/light-fired clay
2.0
350-500
Glazed tiles
8.0
1100 (approx.)
Expanded clay
2.0
1150 (approx.)
The zytan block
4.0
1200 (approx.)
rammed earth, either the roof can be taken off and the rain allowed to wash it
away, or it can be hosed down with water.
Sand and gravel as aggregate in cement products
Sand, gravel and crushed stone are the main constituents of all concrete. Sand
with round or rectangular grains is preferable, with the smallest possible content
of humus, mica or sulphur. It is also an advantage if the sand is not too fine -
coastal sand is considered to be the best sort. It is possible to use sand dried from
the sea, but continual contact with salt water means that it will contain large
quantities of chlorine which corrodes steel. This can easily be washed out with
fresh water. Sea sand is often very fine, but this can be remedied by adding a
coarser sand. High strength is an important quality for aggregate.
Earth as a building material
'From earth you have come, to earth you shall return.'
In 1982 a large exhibition and conference took place at the Pompidou Centre in
Paris entitled 'A forgotten building practice for the future'. The theme was earth
as a building material. Earth can be used in construction for more than just
trenches and potato cellars. It is the second most important building material
after bamboo. More than 30 per cent of the world's current population live in
earth houses, which once also flourished in Western Europe but have since been
