Factors Influencing Bond Strength of Adhesive Anchors

This paper presents results of a comprehensive test program that investigated various factors with the potential to influence the bond strength of polymer-based adhesive anchors. 20 products from 12 manufacturers were included in the program for a total of 765 tests. To establish a reference bond strength, baseline tests were performed at room temperature for anchors installed in cleaned, dry holes. Individual factors were isolated through separate test series that maintained baseline conditions, except for the variable under consideration. The variables that were investigated included those that could be anticipated to occur during and after installation. Factors occurring during installation included the condition of the drilled hole, differences in the concrete strength, and differences in concrete aggregate. Factors occurring after installation included a short-term adhesive curing period and loading at an elevated temperature. This research demonstrates that reliable predictions of adhesive anchor performance are only practical by product-specific and condition-specific testing.