Title: Epoxy Coated Reinforcement and Crack Control

Author(s): D. T. Blackman and R. J. Frosch

Publication: Symposium Paper

Volume: 225

Issue:

Appears on pages(s): 163-178

Keywords: crack control; crack spacing; crack width; epoxy coated reinforcement

DOI: 10.14359/14383

Date: 3/1/2005

Abstract:
Epoxy coated reinforcement is often used as a means of improving the durability of structures. The use of epoxy coating on reinforcement, however, has been shown to decrease bond strength resulting in increased crack spacing and crack widths relative to uncoated reinforcement. While the general influence of epoxy coating on cracking is recognized, there is scare data available to substantiate the magnitude of the effect. The objective of this research was to evaluate the influence of epoxy coating on crack spacing and crack widths. Ten specimens were subjected to a constant moment region, and the crack spacings and widths were measured over a range of reinforcement stress levels. Primary variables included the epoxy coating thickness, reinforcement spacing, and reinforcement stress. The results from this study showed that epoxy coating thickness affects both crack spacing and width. In general, as coating thickness is increased, crack width increased and crack spacing decreased. While crack control aimed at minimizing corrosion of reinforcing steel may not be of concern when epoxy coated steel is used, crack control remains an important design consideration for aesthetic reasons, for increasing structural durability, and for the design of water-retaining or other specialized structures.