Title: Behavior of Joints Using Reinforced Fibrous Concrete
Author(s): R. John Craig, Sitaram Mahadev,
C.C. Patel, Manuel Viteri, and Czaba Kertesz
Publication: Symposium Paper
Appears on pages(s): 125-168
Keywords: beams (supports); columns (supports); cyclic loads;
ductility; earthquake resistant structures; earthquakes, fiber
reinforced concretes; joints (junctions); loads (forces);metal . fibers, reinforced concrete, reinforcing steels, stirrups.
From exploratory research of reinforced fibrous concrete, it has been shown that fibrous concrete is potentially superior and less costly than the conventional reinforced concrete. The testing program consisted of ten beam column joints with half of these joints containing 1.5 percent by volume of concrete of steel hooked end fibers. The beam column joints were constructed with less hoops than a conventional seismic joint would have, ac-cording to design specifications of the American Concrete Institute code ACI 318-77). In studying the behavior of these beam column joints, two failure conditions were found: 1) critical regions whose inelastic behavior is controlled by bending, and 2) critical regions whose inelastic behavior is controlled by high shear existing in the region. The results of the testing will be described. From the analysis of the results, it can safely be concluded that the hooked end steel fibers in the joint region provided: 1) better bond; 2) better confinement of the concrete; 3) a stiffer member; 4) higher moment capacity; 5) higher shear strength; 6) more ductility; and 7) significant improvement in the energy dissipation capacity than did the plain concrete joint.