Pig in the Middle

The bond strength between overlays and bridge decks that are sealed with epoxy resin or high molecular-weight methacrylate is evaluated through field and laboratory tests. Microsilica-modified concrete, latex-modified concrete, and super-dense plasticized concrete overlays are included in this study. Despite often stark variations in the values of bond strength obtained from different testing methods, the data universally suggest that the use of a sealer at the interface reduces the available bond strength by more than 50%. Extra surface preparation techniques, such as light sandblasting of the sealed surface or broadcasting sand over the sealed interface while the sealer is curing, are effective and simple methods for restoring a significant portion of the bond strength.