Civil Engineering Reference
In-Depth Information
Wastewater treatment plant, Santa Rosa, California. (Courtesy of Simpson Timber
Company.)
Normally, the structural designer is responsible for the design of reinforced concrete
structures, while the design of the formwork and its construction is the responsibility of
the contractor. For some structures, however, where the formwork is very complex, such
as for shells, folded plates, and arches, it is desirable for the designer to take responsibility
for the formwork design. There does seem to be an increasing trend, particularly on larger
jobs, to employ structural engineers to design and detail the formwork.
The contract documents should clearly specify the responsibility of each party for
the work. It is wise to allow the contractor as much room as possible to plan his or her
own formwork and construction details, because more economical bids will often be the
result.
It is to be remembered in contract law that if the contract documents describe exactly
how something is to be done and at the same time spell out the results to be accomplished,
it is not generally enforceable. In other words, if the exact form of the construction details
is specified in the contract and followed by the contractor, and the formwork fails, the
contractor cannot be held responsible.
20.3
MATERIALS USED FOR FORMWORK
Several decades ago, lumber was the universal material used for constructing concrete
forms. The forms were constructed, used one time, and torn down, and there was little
