Allowable Mechanical Properties of Wood-Bonding Adhesives for Structural Design ASTM D5574

Scope:

ASTM D5574 covers a set of Standard Test Methods describing the principles used to decide allowable mechanical properties for adhesives, which can be applied to design adhesive-bonded joints for structural components or assemblies of wood or of wood with other materials. The set of tests in ASTM D5574 enable decisions on adequate safety factors to be applied to the allowable design stress, ensuring durability of engineered structures. The properties determined by the standard ASTM tests listed in ASTM D5574 are allowable shear stress, allowable tensile stress, and allowable shear modulus. The corresponding referenced set of fifteen ASTM tests are: D245 / D897/ D905/ D907 /D1101 / D1151/ D2555/ D2559/ D2915/ D3931/ D3983/ D4017 /D4502/ D4680/ D4896. The ASTM D5574 provides the procedural variations as may be needed from the standards and special directions for applying the results. Important guidance points in ASTM 5574 that need highlighting are:

•  Time-to-failure data derived from creep-rupture testing (see Test Method D4680) indicate the ultimate strength of an adhesive bond various temperature and moisture levels
• Property degradation due to aging (permanence) is evaluated by strength tests after constant high temperature and moisture aging of test specimens.
• All durability, permanence, and creep factors derived from shear tests are assumed to apply to tension stress resistance as well.
• If the final adhesive application involves wood treated with a preservative, fire retardant, or any other chemical, then the tests shall be conducted using similarly treated wood adherends.

Result:

The  allowable  shear strength is reported in pounds per square inch (psi).