Intermediate-scale test developed to screen adhesive fire performance in glued-laminated timber before full-scale testing

When a new engineered wood adhesive is developed for use in a fire-rated assembly, it must first pass a full-scale fire test, for example, a test in accordance with ASTM E119 in the United States. Although full-scale tests serve as the necessary entry to the marketplace, they are extremely costly and reflect the performance of the entire assembly and not just the adhesive. As a result, it is difficult to quantify differences in adhesive performance under elevated temperatures or fire conditions with these tests. Here, we present the results from a new test method developed at the USDA Forest Service, Forest Products Laboratory, to examine adhesive wood performance in glulam beams. The test is part of a larger research program for examining different adhesive formulations. The goals of the intermediate-scale test were to understand differences between adhesive formulations and to provide guidance regarding the performance for full-scale adhesive tests.