dc.contributor.author | Hadje-Ghaffari, Hossain | |
dc.contributor.author | Choi, Oan Chul | |
dc.contributor.author | Darwin, David | |
dc.contributor.author | McCabe, Steven L. | |
dc.date.accessioned | 2016-02-22T20:34:20Z | |
dc.date.available | 2016-02-22T20:34:20Z | |
dc.date.issued | 1992 | |
dc.identifier.citation | Hadje-Ghaffari, H., Choi, O.C., Darwin, D., and McCabe, S.L., "Bond of Epoxy-Coated Reinforcement to Concrete: Cover, Casting Position, Slump, and Consolidation," Research Grant No. ECE-8616228, SL Report 92-3, The National Science Foundation, June 1992, 45 pp. | en_US |
dc.identifier.uri | http://hdl.handle.net/1808/20329 | |
dc.description.abstract | The effects of concrete cover, casting position, concrete slump, and degree of consolidation
on the reduction in bond strength between reinforcing bars and concrete caused by epoxy coating
are described. Tests include beam-end specimens containing No. 5, No. 6, No. 8, and No. 11
bars. Bottom-cast and top-cast bars with 1, 2, or 3 bar diameters of cover are evaluated. Concrete
slump ranges from 21/4 to 8 in. Some specimens containing high slump concrete are not vibrated.
The results of the study are used to develop improved development length modification factors for
epoxy-coated bars.
Epoxy coatings significantly reduce bond strength. However, the extent of the reduction is
less than used to select the development length modification factors in the 1989 ACI Building Code
and the 1989 AASHTO Bridge Specifications for bars with cover < 3 bar diameters or a clear
spacing < 6 bar diameters. The development length modification factor can be reduced from 1.5 to
1.35 for these bars. The relative bond strength of epoxy-coated reinforcement increases as cover
increases. In most cases, the bond strength of coated bars exceeds the bond strength of uncoated
bars that have one bar diameter less cover. As a result, the current provisions of ACI 318-89 are
realistic as they are applied to epoxy-coated bars with a cover :2: 3 bar diameters and a clear spacing
:2: 6 bar diameters. However, the provisions of the 1989 AASHTO Bridge Specifications are
somewhat unconservative for these bars and should be modified. The ratio of bond strength of
bottom-cast bars to the bond strength of top-cast bars, B/T, is about the same for coated and
uncoated bars cast in low slump concrete. The ratio increases significantly for uncoated bars and
decreases slightly for coated bars as slump increases. The results indicate that the upper limit on
the product of the epoxy-coating factor and the top-bar factor can be reduced from 1.7 to 1.5. A lack of vibration has a negative effect on the bond strength of both coated and uncoated reinforcement
in high slump concrete.
This is the fifth in a series of reports describing research at the University of Kansas on
epoxy-coated reinforcement The research is aimed at gaining a better understanding of the bond
of epoxy-coated reinforcement to concrete and developing design procedures that accurately reflect
the changes in bond strength caused by epoxy coating. | en_US |
dc.publisher | University of Kansas Center for Research, Inc. | en_US |
dc.relation.ispartofseries | SL Report;92-3 | |
dc.relation.isversionof | https://iri.ku.edu/reports | en_US |
dc.subject | Bond (reinforcement to concrete) | en_US |
dc.subject | Coatings | en_US |
dc.subject | Deformed reinforcement | en_US |
dc.subject | Epoxy-coated reinforcement | en_US |
dc.subject | Pullout tests | en_US |
dc.subject | Reinforcing steels | en_US |
dc.subject | Structural engineering | en_US |
dc.title | Bond of Epoxy-Coated Reinforcement Concrete: Cover, Casting Position, Slump, and Consolidation | en_US |
dc.type | Technical Report | |
kusw.kuauthor | Darwin, David | |
kusw.kudepartment | Civil/Environ/Arch Engineering | en_US |
dc.identifier.orcid | https://orcid.org/0000-0001-5039-3525 | |
kusw.oapolicy | This item does not meet KU Open Access policy criteria. | |
dc.rights.accessrights | openAccess | |