Unless a sufficient development length of steel is embedded in concrete, the bar will pull out before it yields. In 1990 a portion of the Pittsburgh Midfield Terminal failed during construction. In a precast concrete beam, the bottom reinforcing bar was embedded only 185 mm (7 inches), which is much shorter than necessary (Thornton and DeScenza 1997).
Reference:
- Thornton, C. H., and DeScenza, R. P. (1997). Construction Collapse of Precast Concrete Framing at Pittsburgh’s Midfield Terminal. Forensic Engineering: Proceedings of the First Congress, K. L. Rens, ed., ASCE. New York, N. Y. 85-93.
