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Wire
Sawing
Wire sawing
is a technique that originated in quarries to extract
stone. It has proven to be an ideal choice for removal
of thick sections of concrete. A multi-strand cable with
diamond segments is threaded through a series of pulleys
and is continuously pulled through the concrete. Since
virtually no concrete structure or cross-section is too
large to cut, wire saws are used where other cutting
methods are impractical. The only restriction is the
lifting and removal specifications of the job. Wire
sawing is ideal for removing large sections of heavily
reinforced concrete, such as piers, towers and bridge
sections, and cutting concrete in areas where work space
is restricted.
A wire saw
consists of a multi-strand cable with diamond segments
that are threaded through a series of pulleys attached
to a drive wheel that is powered by a hydraulic power
unit. The combination of the spinning wire and constant
pulling force cuts a path through the concrete and steel
reinforcement. A typical wire diameter is 3/8 inch (10
mm). Wire saws can cut in any orientation, vertical or
horizontal. Because the length of wire can be made to
virtually any length, the cutting depth is unlimited.
A nuclear
power plant renovation in South Haven, Michigan was
performed with the use of a wire saw. Four large blocks
of concrete with a steel liner were cut in order to
change steam generators. The blocks of concrete were
3-1/2 foot (1.1 m) thick with 2 inch (51 mm) diameter
rebar and lined with 1/4 inch (6 mm) thick steel plate.
The largest block measured 28 foot by 27 foot (8.5 x 8.2
m). The sawing was accomplished in nine days using two
four-man crews. The capability of the wire saw, in
combination with the expertise of the professional CSDA
cutting contractor, allowed this project to be completed
in time and under budget.
(description of wire
sawing provided by: Concrete Sawing & Drilling
Association) |
