Civil Engineering Reference
In-Depth Information
Guillotining
This is possible for smaller blocks with clear layer-
ing. This splits the stone with one blow and is the
most labour- and energy-saving technique. It is
also the principle upon which modern equipment
research and development bases its work. Some
methods create an artificial tension within the rock
with the help of a strong vice. Fractures then occur,
which spread out when the axe falls, and in a sin-
gle moment maximize the tension in one direction.
The maximum size available for a rough block,
using modern equipment to split the stone, is up to
250 cm
50 cm, depending upon the type of
stone. Smaller splitting machines can be carried by
two men; these can split stone up to 10 cm thick
and also work on loose stone.
Sawing
Another common method for dividing the block. A
circular saw or frame saw, preferably with a dia-
mond blade, can be used. The frame saw is often
used for the production of facing panels. The capacity of a frame saw on hard
stone is approximately 30 cm per hour. Circular saws are used for all types of
stone and cut considerably faster.
Figure 7.3: The frame saw used for cutting
stone blocks.
Jetflame
This can be used on quartz stone.
Waterjet
A waterjet has been developed for cutting stone, using a thin spray of water at
an extremely high flow speed which cuts stone like butter.
The finishing process
The finishing process is determined by how the stone is to be used. For structur-
al use and foundations the stone does not need much working - the surface can
be evened out with a hammer. For cladding panels, tiles, etc., the stone requires
planing, grinding and polishing.
Sorting and cutting slate
Every slate quarry has its own characteristics with respect to accessibility, angle
of layers and splitting. In particularly favourable locations the layers of rock are
