Performance of an Architectural Precast Concrete Building Facade under Seismic Loading: Influence of the Initial Design Drift

Architectural precast concrete (APC) cladding system is a critical nonstructural component of commercial real estate buildings. The design of this system is based upon the building code, which specifies both the design forces for components as well as the expected inter-story deflection that the system will be expected to accommodate. APC systems have gone through significant changes over the past thirty years, in particular with the changes in design displacement requirements during the 1990s, which significantly changed the displacement demands that the systems were required to accommodate. The Pathways project, part of the National Science Foundation’s NEES research initiative, conducted a series of experiments on architectural precast concrete (APC) cladding which was designed to modern building code requirements. A significant finding from the study was that the system performed well while loaded to inter-story deflections below the design deflection of the cladding. This paper will discuss the types of damage observed when the applied displacement exceeds the design deflection. Using the information obtained from the Pathways experiments, the authors will adjust the findings to provide performance expectations for extant APC systems with varying levels of initial design displacement.