Title:
Bond Characteristics of Deformed Reinforcing Steel Bars
Embedded in SIFCON
Author(s):
Ali M. Hamza and Antoine E. Naaman
Publication:
Materials Journal
Volume:
93
Issue:
6
Appears on pages(s):
578-588
Keywords:
bond stress; deformation; reinforcing steels; slippage; slurries.
DOI:
10.14359/9864
Date:
11/1/1996
Abstract:
The bond-versus-slip characteristics of deformed reinforcing steel bars embedded in slurry-infiltrated fiber concrete (SIFCON) were determined for different values of bar embedment length, net concrete cover, compressive strength of SIFCON, and bar diameter: Measurements included bar tension force, slip at free and loaded ends of the bar, and steel and concrete strain distributions along the bar embedment length. Crack patterns were monitored and modes of bond failure were observed. It is observed that SIFCON leads to a significant increase in average bond stress, bond stiffness, and pullout work of bars when compared not only to plain concrete but to highly confined concrete. Average bond stresses as high as 2500 psi (17.25 MPa) were measured, while maximum pullout forces were maintained for slips IO times larger than those observed for plain concrete. The initial bond stiffness was 250 and 150 percent that of plain and confined concrete, respectively, while total pullout work was more than twice and 20 times that observed for plain and confined concrete, respectively. Everything else being equal, the average bond stress of reinforcing steel bars embedded in SIFCON increased with an increase in the compressive strength of SIFCON and the concrete cover and decreased with an increase in bar diameter: