Rachel E. Henkhaus, Sandra Villamizar, and Julio A. Ramirez



The allowable range of epoxy coating thickness specified by ASTM A775/A775M is 175 to 400 μm (7 to 16 mils).

This study investigates the impact on structural performance of increasing the upper limit of epoxy coating thickness to 460 μm (18 mils) with respect to deflections, cracking, and bond strength of tension splices. Twenty beam specimens containing single splices as well as splices of bundled bars were tested to failure.

The experimental parameters were ranges of epoxy coating thicknesses (300 to 380 μm [12 to 15 mils] and 460 to 530 μm [18 to 21 mils]) and bar sizes No. 16 and 29 [No. 5 and 9]).

Test results confirmed the applicability of current code requirements for development and splice length of epoxy-coated bars in tension in ACI 318-14 and AASHTO LFRD 2014, including bars in bundles, up to a coating thickness not to exceed 460 μm (18 mils)


bond strength; deformed reinforcement; development length; epoxy-coating thickness; lap connections; normalweight concrete