Included code sections – (1), (4)

Excluded code sections – (2), (3)

This section applies only to beams.

b_t is taken as the width on the tension face.

d is taken as the depth from the compression face (as determined from the "Code Min. Reinforcement Location" setting) to the centroid of reinforcement located closest to the tension face. In PT beams the tendon locations are included in this calculation.

For cross sections with multiple concrete mixes, the maximum f_ck is used.

See "Code Minimum Reinforcement" for details regarding which face (top or bottom) that the reinforcement will be added to.

For RC beams, post-tensioning is ignored.

For PT beams, bonded post-tensioning that is on the tension-most side of the cross section centroid, or is within 10% of the cross section depth of the centroid elevation, is considered as un-tensioned reinforcement. For A_sF_y requirements, tendon (f_py – f_se) is utilized as the available yield stress. Bonded tendons at an angle to the cross section will have vector components of their reinforcement areas applied toward these requirements.

For unbonded PT beams, un-tensioned reinforcement is added to provide an ultimate moment capacity greater than 1.15 times the cracking moment.

The cracking is assumed to be top (hogging moment) or bottom (sagging moment) based upon the "Min. Reinforcement Pattern" selected in the design strip segment or design section.

Only sections within 1/6 of the span length from supports or 1/6 of the span length from midspan are checked, as these are considered as the likely locations of first cracking of concrete.

See ""Cracking Moment" Used in Design Calculations" for a theoretical discussion of the cracking moment (note that a 1.15 factor is used in EC2).

The cracking stress is taken as f_ctm,fl in accordance with EC2 clause 3.1.8. For cross sections with multiple concrete mixes, the maximum f_ck for the cross section is used.