Title: Increased Joint Hoop Spacing in Type 2 Seismic Joints Using Fiber Reinforced Concrete

Author(s): Paul R. Gefken and Melvin R. Ramey

Publication: Structural Journal

Volume: 86

Issue: 2

Appears on pages(s): 168-172

Keywords: beams (supports); columns (supports); concretes; cyclic loads; ductility; earthquake-resistant structures; energy dissipation; spalling; fiber reinforced concretes; hoops; joints (junctions); metal fibers; stiffness; strength; Structural Research

DOI: 10.14359/2674

Date: 3/1/1989

Abstract:
Ten beam-column joints were tested to determine whether increases in joint hoop spacing in conventional concrete Type 2 joints (seismic joints) could be achieved using steel fiber concrete in place of conventional concrete in the joint region. Two cyclic loading sequences were applied to each beam-column specimen. The properties of ductility, ultimate strength, energy dissipation capacity, and joint stiffness of conventional concrete specimens were compared with those for steel fiber concrete specimens having differing increases in joint hoop spacing. It was determined that steel fiber concrete specimens with joint hoop spacings of up to 1.7 times the spacing recommended by ACI-ASCE Committee 352 for a conventional concrete Type 2 joint had the same or better ductility, ultimate strength, energy dissipation capacity, and joint stiffness. This preliminary study suggests that Type 1 joints (nonseismic joints) with steel fiber concretes could be considered for use in place of Type 2 joints in seismic zones.