Figure b6-1 introduces a reinforced concrete section with notations. The serviceability moment of resistance Mct,ser is unknown.
Criterion
The concrete is cracked if:
σct > fct,eff
(b6.1)
where:
σct
is the tensile stress in concrete
fct,eff
is the mean value of the tensile strength of the concrete effective at the time
when the cracks may first be expected to occur: fct,eff =
fctm
or lower,
(fctm(t)),
if cracking is expected earlier than 28 days
Moment of resistance of an uncracked section Mct,ser
The concrete section includes reinforcement. With the assumption of a non-cracked section,
the area of the homogeneous section is defined: