Title: Bond and Creep Characteristics of Coated Reinforcing Bars in Concrete

Author(s): James R. Clifton and Robert G. Mathey

Publication: Journal Proceedings

Volume: 80

Issue: 4

Appears on pages(s): 288-293

Keywords: bonding; creep tests, epoxy resins; organic coatings; polyvinyl chloride;pullout tests; reinforced concrete; reinforcing steels.

DOI: 10.14359/10848

Date: 7/1/1983

Abstract:
Organic coatings are used to protect reinforcing bars embedded in concrete from corrosion. An important consideration in the use of coated reinforcing bars is the effect of the coafing on the strength of the bond formed between reinforcing bars and concrete. In this paper the effects of nine epoxy coatings and one polyvinyl chloride coating on the bond characteristics of reinforcing bars are discussed. The bond properties were determined by carrying out pullout and creep tests. In the pullout tests, increasingly higher Ioak were applied to reinforcing bars embedded in concrete until the bond strength between the bar and concrete was exceeded. In the creep tests reinforcing bars were subjected to tensile stresses of either 15,000 psi (103 MPa) or 30,000 psi (206 MPa) and their slips were measured for two years. Resufts of ihe pullout studies are compared with those of the creep studies on the basis of pullout bond stress ratios (BR) and creep ratios (CR).