Abstract

Connections play an important role in building construction for all materials, and the precast concrete industry is no exception. The field installed connections used in precast concrete systems are often much simpler than those required in steel, timber, or even cast-in-place concrete systems. This simplicity gives precast concrete an important advantage over other building systems by allowing quicker erection times, and ultimately early completion of the building project. However, the simplicity and use history may lead the engineer to assume connections are as robust as the rest of the structural system, and thus connection design becomes routine.

This thesis evaluates the behavior of the Cazaly hanger under vertical load and proposes a new design standard for the connection. The Canadian Prestressed Concrete Institute devised a research program in 1965 to evaluate the behavior of the hanger, which led to a shear-friction design for the hanger within the PCI Design Handbook. However, current tests show the hanger does not follow shear-friction behavior, but instead behaves according to concrete breakout. Reassessment of the 1965 specimens revealed shear-friction to be a poor predictor of capacity, while concrete breakout provides conservative predictions. A revision to the current PCI Design Handbook that will produce more reliable Cazaly hanger designs is proposed.