2205.4.2 Concrete Encased Beams

Where the design strength of concrete encased structural steel beams is determined from the plastic stress distribution of the structural steel beam alone in accordance with AISC-LRFD or from AISC 335 where the allowable bending stress of the structural steel beam alone is used, the yield stress of the structural steel shall not exceed 36 ksi (250 Mpa), the steel beam depth shall not exceed 40 inches (1016 mm), the concrete compressive strength shall not be less than 3,000 psi (20 685 kPa) and the concrete aggregate shall conform with ASTM C33.