At 39 stories and 420 ft (128 m) high, The Paramount (located in San Francisco, California) is the tallest concrete structure in addition to being the tallest precast, prestressed concrete framed building in Seismic Zone 4 (a double record). It is the first major high rise building to be braced by an architecturally finished exposed precast concrete ductile frame. The reinforcement used to create this seismic ductile frame includes post-tensioning and high strength reinforcing steel. All this represents a major milestone in the development of precast/prestressed concrete. The building is basically an apartment complex, although the lower floors accommodate retail space, vehicle parking and recreational amenities. This article presents the design considerations, construction highlights, research and development, and code approval process that led to the realization of this structure.
