For optimal fire safety, which material is preferred for the main structure in tilt-up buildings?

Concrete is preferred for the main structure in tilt-up buildings due to its excellent fire resistance properties. Being non-combustible, concrete does not ignite or contribute to the spread of fire, which is a critical factor in maintaining safety during a fire event. Additionally, concrete's thermal mass allows it to withstand high temperatures without losing structural integrity, providing more time for occupants to evacuate and for firefighters to respond.

Steel, while strong and capable of supporting heavy loads, can lose its structural strength in high temperatures, which can lead to failure during a fire. Wood is combustible and poses significant fire hazards, making it less ideal for safety in buildings. Brick, while offering some fire resistance, does not provide the same level of structural integrity and thermal mass as concrete in tilt-up construction, where the panels are poured and cured on-site and then lifted into place, optimizing strength and fire resistance effectively. Thus, concrete is the clear choice for ensuring optimal fire safety in tilt-up buildings.