As specified in LFD Art. 9.18.2.1, a minimum ultimate capacity requirement at the critical section is equal to at least 1.2 times the cracking moment. The cracking moment is the moment that will cause the cracking stress to be reached in the bottom of the beam. The cracking requirement may be waived if the area of steel provided is at least 1.33 As-reqd.

The definition of the critical section in the LFD code is unclear. It can be interpreted as being the section with the highest Mu-reqd, which is generally near the midspan, or it can be the section with the lowest cracking ratio (Mu-prvd/Cracking Moment). Precast/Prestressed Girder provides the cracking ratio at several points along the beam, and is shown on the printout under Ultimate Capacity.