Seismic, Creep, and Tensile Testing of Various Epoxy Bonded Rebar Products in Hardened Concrete




DISCLAIMER STATEMENT

This document is disseminated in the interest of information exchange. The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California or the Federal Highway Administration. This publication does not constitute a standard, specification or regulation. This report does not constitute an endorsement by the Department of any product described herein. For individuals with sensory disabilities, this document is available in Braille, large print, audiocassette, or compact disk. To obtain a copy of this document in one of these alternate formats, please contact: the Division of Research and Innovation, MS-83, California Department of Transportation, P.O. Box 942873, Sacramento, CA 94273-0001.



1. INTRODUCTION

1.1 Problem Statement

For certain applications, the California Department of Transportation (Caltrans)

uses epoxy cartridge adhesives for bonding rebar into holes that are drilled in hardened concrete. Caltrans started using these adhesives on plain rebar since previous research and testing was completed on them. At some point, Caltrans used a large quantity of epoxy-coated rebar for earthquake retrofitted bridge structure rehabilitation projects. Concern was expressed about using epoxy-coated rebar with epoxy cartridge adhesives. Problems that could occur are long-term creep under sustained tensile loading and slip or strength loss during cyclic loading that takes place during a seismic event. The International Conference of Building Officials (ICBO) had suggested that bars with any coatings should be treated as a new, different bar and would require a new set of tests. These tests have yet to be completed.

Caltrans’ Division of Materials Engineering and Testing Services recommended to Structures Design that a separate set of ICBO seismic tests be performed on epoxycoated

bars with epoxy cartridge adhesives. These tests would

have to pass Caltrans’ Augmentation to ICBO-AC58 [1] to be permitted for use in concrete

structures. They also recommended that a considerable reduction in allowable loads

be imposed on untested coated bars until the effects of coatings could be determined.

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