Title:
Experimental Investigation of Bond Strength of
Hot-Dip Galvanized Reinforcement in Normal- and
High-Strength Concrete
Author(s):
Bilal S. Hamad and John A. Mike
Publication:
Structural Journal
Volume:
100
Issue:
4
Appears on pages(s):
465-470
Keywords:
bond; corrosion; lap splice; reinforced concrete.
DOI:
10.14359/12655
Date:
7/1/2003
Abstract:
This paper reports on research conducted at the American University of Beirut to evaluate the effect of hot-dip galvanizing on bond strength of reinforcement in concrete structures. The role of concrete compressive strength was assessed by testing normal- and high-strength concrete specimens with nominal compressive strength values of 28 and 60 MPa, respectively. The test results will have an implication on the development length and splice length design provisions of hot-dip galvanized reinforcement in design codes. For each level of concrete strength, a series of six specimens was tested. In each series and for each of three bar sizes—20, 25, and 32 mm—two identical companion beams, except for whether the bars were black or galvanized, were tested. Each beam was reinforced on the tension side with reinforcing bars spliced at midspan in a constant moment region. The mode of failure was splitting of the concrete cover in the splice region. The effect of galvanizing was evaluated by comparing the mode of failure, load-deflection curves, and average bond strength values. Test results indicated that whereas galvanizing was found to have a negligible effect on bond strength of reinforcement in normal-strength concrete (NSC), it caused an average 20% decrease in bond strength of reinforcement in high-strength concrete (HSC).