scope:

General-This specification covers normalweight, high-strength concrete in structures that must be designed for moderate to high seismic applications. More specifically, this specification applies to structures:

•   Located in Seismic Zones 2, 3, or 4 defined by the Uniform Building Code;

•   Assigned to Seismic Performance Categories C, D, or E of the BOCA/National Building Code (1993 and subsequent editions) or the Standard Building Code (1994 or subsequent editions); or

•   Seismic Design Categories C, D, E, or F of the International Building Code or the National Fire Protection Association (NFPA) 5000 Building Construction and Safety Code.

Irrespective of seismic zone, seismic performance, or seismic design category, this specification shall apply to normalweight, high-strength concrete in intermediate or special moment frames and intermediate or special structural walls as defined in ACI 318-05.

Supplemental specification-This specification supplements "Specifications for Structural Concrete (ACI 301-05)" by providing more restrictive selected requirements when high-strength concrete is used in moderate to high seismic applications. The requirements of ACI 301-05 shall apply unless otherwise specified in this specification.

High-strength concrete-Unless otherwise specified, high-strength concrete is defined as concrete having a specified compressive strength for design of 6000 psi (41 MPa) or greater.

Dual units-The values stated in inch-pound or SI units shall be regarded separately as standard. The SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.