Section 8.6.2.3
Midspan Two Way Minimum Reinforcement
For span segment strips, this criterion is only
applied when the span ratio is in the middle two-thirds of the span.
For a span with no supports
(as determined by the declaration of supports in the design strip segment),
this criterion is always applied.
Gross-section,
linear-elastic stress calculations are used.
For sections with multiple
concrete strengths, the minimum concrete strength is used to determine the
limiting stress.
For sections with multiple
concrete strengths, approximate extreme fiber stresses and centroid stresses
are calculated and reported.
If
is exceeded the entire tensile load,
Nc, is
taken by bonded reinforcement.
User defined reinforcement
on the appropriate face and bonded post-tensioning that is in the tension zone
is counted toward the requirement. Vector components are taken of reinforcement
and bonded post-tensioning that are not orthogonal to the cross section. Usable
bonded tendon stresses are limited to the minimum of (fpy –
fse), (0.5fpy) and 30
ksi.
Reinforcing bar stresses are
limited to the minimum of (0.5
fpy)
and 30 ksi.
The reinforcement is only provided where stresses
exceed , the minimum length requirements of 8.7.5.5.1 are considered with code
span detailing requirements.
No check is made to ensure
that the structure is post-tensioned.