Development of a precast concrete shear-wall system requiring special code acceptance

Precast, prestressed wall panels comprising thin concrete sections are not commonly used as seismic shear walls. Many engineers and code officials view prestressed materials as nonductile, and the connections between the sandwich wall panels and the foundation may suffer from brittle joint failures. The authors have designed a new load-limiting foundation connection for precast, prestressed panels used as shear walls that prevents the development of excessive uplift forces in the joint. This connection allows precast, prestressed concrete wall panels, such as hollow-core, to act as shear walls in resisting seismic loading without relying on wall ductility or causing an anchorage failure in a thin concrete section of the wall panel (where a connector is located). This unique connector allows the wall system to behave unlike that anticipated by building-code-defined design methods. Building codes require the behavior of new systems to be compared (and proven similar) with that of code-conforming behavior before being used. This paper describes the development and testing of the proposed load-limiting connector and wall system and the wall design approach needed to obtain special building code approval for its use.