ASTM D7247-07a

A discussion of the issues and limitations associated with the measurement of strength properties of adhesive bonds in shear by compression loading is found in Test Method D 905.

While various combinations of test temperature and heat exposure duration can be used, the provisions specified in 7.2.4 shall be based on the understanding that the objective of this test method is to evaluate adhesive bond performance just before wood begins to burn and the elevated temperature is selected to be slightly below the unpiloted ignition temperature for wood when taken into account the specific product and its end-use applications.

When using this test method, consideration shall be given to the unique production conditions, such as wood moisture content, applied spread rate, press pressure, and curing temperature of the adhesive.

1.1 This standard describes a test method for evaluating the comparative shear strength of a planar adhesive bond at both ambient and elevated temperatures relative to the performance of solid wood under the same conditions. The test method is based on the breaking load after the specimen is exposed to either ambient or a constant elevated temperature for a specified duration as described in Section . This standard does not preclude the development and implementation of other methods that provide equivalent performance meeting the intent of this method.

1.2 This test method is intended for the evaluation of adhesives that can be used to assemble test specimens in accordance with Test Method D 905. The evaluation of other types of adhesives, such as the binder systems used for strand-based products, is beyond the scope of this test method.

1.3 This test method is intended for the evaluation of adhesives as a component of laminated wood products at elevated temperatures. The evaluation of fire performance on fire-rated laminated wood products or assemblies is beyond the scope of this test method.

1.4 While it is preferable to use solid wood specimens as described in Section 6 as the control, structural composite lumber products as defined in Specification D 5456 shall be permitted for use provided they are matched with the bonded specimens in accordance with Section 6 and the ignition temperature is not significantly lower than solid wood of the same species.

1.5 The exact formulation of adhesive supplied to the manufacturer of laminated wood products shall be evaluated. Modifications to the adhesive formulation require a separate evaluation unless approved by the manufacturer of the laminated wood product, qualified agency, and code evaluation agency.

1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

This standard does not purport to address all of the safety concerns, such as the fire hazard, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.