The required quantity of negative moment reinforcement in the deck is computed based on the sum of precast and composite moments multiplied by the appropriate g factors (for the maximum negative moment). The required amount of top (and bottom, if any) steel shown represents the amount of steel associated with the beam under consideration and should be provided within the effective area.

The top steel is assumed to be located at mid-height of the slab. Bottom steel, which is occasionally necessary to avoid an over-reinforced condition, is assumed to be located at two inches (50 mm) from the bottom flange of the precast (compression face).

Although LRFD Art. 5.14.1.2.7c states that "if the calculated stress at the bottom of the joint for the combination of superimposed permanent loads, settlement, creep, shrinkage, 50% live load, and temperature gradient, if applicable, is compressive, the joint may be considered fully effective," Precast/Prestressed Girder does not check this and always assumes that the joints at the internal piers are fully effective.

Continuity steel or negative moment reinforcement is designed using the LRFD design provisions, as specified in LRFD Art. 5.7, assuming that the mild steel in the deck is the only reinforcement in the section under investigation. Consider the concrete strength of the girder as governing the design. Resistance factor for flexure or tension of reinforced concrete is computed as per LRFD Art. 5.5.4.2.1.

Precast/Prestressed Girder checks for maximum and minimum reinforcement limits as specified in LRFD Art. 5.7.3.3. For minimum reinforcement, the limit for reinforced concrete is used. Precast/Prestressed Girder complies with LRFD Article 5.11.1.2.3.