An assessment of CO₂ emission of the structural composite hybrid beam based on strain compatibility

Structural composite hybrid beams consist of a rolled wide-flange steel shaped to allow the bottom flange and/or a portion of the web of the steel section partially encased in pre-cast concrete. For each limit state, a series of plastic strain distributions corresponding to a particular location of the neutral axis and stresses in the reinforcing steel and steel section was assumed. For the assumed strain distributions, equations were derived based on equilibrium equations and solved for the neutral axis and stress levels in the concrete block, the reinforcing steels and the steel section. The calculated stress levels in the structural components were compared with the assumed stresses obtained from the assumed strain distribution. The strain compatibility approach allows for analytical calculations that correlate well, thus avoiding the need for complex and tedious calculations of the flexural moment capacity for complex structures. In this work, Green Beam and steel beam with the same flexural moment capacity were compared and the ability of the Green Beam to reduce CO₂ emissions was demonstrated.