At the Constructed Facilities Laboratory (CFL), researchers are improving design procedures for parking garage decks. The research involves investigating the ways in which the precast concrete beam ledges, commonly used to support garage decks, fail. Knowledge of failure modes can be used to develop better designs. With funding from the Precast Concrete Institute (PCI) and the National Science Foundation Center for Integration of Composites into Infrastructure (CICI), graduate students Mohamed Nafadi and Omar Khalaf Alla are measuring and analyzing ledge failure mechanisms. The research is conducted in collaboration with WJE Consulting Engineering Company under the direction of Drs. Sami Rizkalla, Paul Zia and Gregory Lucier. Full-scale experiments along with detailed analytical work demonstrate that the current design procedure overestimates the capacity of the ledges. The results also indicate that several parameters currently not considered by the design procedure directly affect the performance of the ledge. Ultimately, this research will be used to develop a practical design procedure for L-shaped beam ledges to be included in the PCI Design Handbook that is used throughout the world.