Static Behavior of Wood‐Joist Floors at Various Limit States

Abstract

The increased emphasis on limit state design philosophy calls for a corresponding emphasis on the behavior of structural systems up to their ultimate load‐carrying capacities. Fifteen full‐size wood‐joist floors—each having 10 joists—were tested to their ultimate capacities under uniformly distributed loads. Behavior was noted at the design load and at the limit states of first joist rupture and ultimate strength. The general stiffening effect of the sheathing and the two‐way action in each system were compared with the assumed bare‐joist behavior at the design load level. Loads at first joist rupture ranged form 101–228 psf. The ultimate limit state was defined as the highest uniform load that could be applied over the entire floor surface, and magnitudes ranged from 135–383 psf. The mode of failure at the ultimate limit state appeared to depend on the rate of loading.