The influence of fire, sound, and vibration performance requirements on embodied carbon in the design of concrete floors

Structural engineers can reduce the embodied carbon (EC) in building design, often by minimizing structural material. Concrete floors contain considerable EC and are thus the subject of ongoing research. Previous studies that have evaluated the EC for different concrete floor systems often exclude important design considerations such as fire resistance, acoustics, and vibrations. In response, this study assesses how design requirements for fire resistance, sound insulation, and walking vibration affect the EC of eight concrete floor systems. A parametric analysis was conducted to calculate EC when varying the floor span, structural design parameters (concrete strength, loads, deflection limits), and the requirements for the three secondary objectives. The EC increased as the secondary objective requirements increased from a 1-hr to 4-hr fire rating, although the lower ratings considered are more typically found in building codes. Satisfying walking vibration requirements had the smallest effect on EC (an increase of up to 14 %), while fire-resistance rating and sound insulation were found to increase EC up to 55 % and 62 %, respectively, compared to floors meeting minimum structural requirements. While less material-efficient floor systems such as reinforced concrete flat plates had higher EC (up to an average of 400 kgCO₂e/m²), these systems often performed favorably across all secondary objectives. All results are presented in design charts to inform building engineers of low-carbon design solutions while balancing other design requirements.