Civil Engineering Reference
In-Depth Information
than earlier shapes, which relied more on frictional interlock and were
more susceptible to 'brittle' failure. The influence of bond is minimised,
in the standard test, by the application of several thousand cycles of
repeated loading up to 60% of the expected failure load, before loading
to failure.
When a new profile is developed, values of
m
and
k
have to be deter-
mined, in principle, for each thickness of sheeting, each overall depth
of slab to be used, and for a range of concrete strengths. Codes allow
some simplification, but the testing remains a long and costly process.
The
m
-
k
test is also unsatisfactory in other ways [17].
