ASTM D5574-94(R2021) pdf free download

ASTM D5574-94(R2021) pdf free download.Standard Test Methods for Establishing Allowable Mechanical Properties of Wood- Bonding Adhesives for Design of Structural Joints
1. Scope
1.1 These test methods cover the principles for establishing allowable mechanical properties for adhesives that can be used to design adhesive-bonded joints for structural components and assemblies of wood or wood with other materials. These test methods are modeled after Practice D245. 1.2 The properties determined are allowable shear stress, allowable tensile stress, and allowable shear modulus. 1.3 In determination of allowable shear- and tensile-stress levels, these test methods are limited by the horizontal shear and tension perpendicular-to-the-grain capacity of the wood adherends (hard maple, Acer saccharum, Marsh.). The adhe- sives so tested may actually have shear or tensile allowable stresses exceeding the wood, but the determined allowable design stress levels are limited (upper bounded) by the wood in these test methods. If a wood other than hard maple is used for testing the adhesive, then the allowable strengths are upper bounded by the properties of that particular wood. 1.4 The strength properties are determined by standard ASTM test methods. As a result, only procedural variations from the standards and special directions for applying the results are given in these test methods. 1.5 Time-to-failure data derived from creep-rupture testing (see Test Method D4680) provide a measure of the ultimate strength of an adhesive bond as a function of time at various levels of temperature and moisture. 1.5.1 With proper caution, useful service life at a given shear stress level may be extrapolated from relatively short loading periods. 1.6 The resistance of the adhesive to permanent loss of properties due to aging (permanence) is assessed by means of strength tests after constant elevated-temperature and moisture aging of test specimens.1.6.1 Ifthe subject adhesives will be used to bond wood that has been treated with a preservative, fire retardant, or any other chemical to modify its properties, then the permanence of the adhesive shall be tested using wood adherends treated in the same manner. 1.7 Factors for durability, permanence, and creep derived by shear tests and analysis, are assumed to apply to tension (normal-to-the-bond) strength as well. 1.8 Requirements for production, inspection, and certifica- tion of adhesives evaluated under these test methods are not included. 1.9 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.10 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 allowable design stress, n—a stress to which a mate- rial can be subjected under stated service conditions with low probability of mechanical failure within the design lifetime. (D4896) 3.1.1.1 Discussion—Allowable design stress is obtained by multiplying the basic stress by a safety factor and possibly one or more modification factors as required by the intended service environment. 3.1.2 allowable shear stress, n—in an adhesive-bonded joint, the allowable design stress for structural joints subjected to shear force. 3.1.3 allowable tensile stress, n—in an adhesive-bonded joint, the allowable design stress for structural joints subjected to tension force. 3.1.4 creep rupture, n—the fracture of a material resulting from a sustained stress (or sum of stresses) above the creep rupture limit. 3.1.4.1 Discussion—The material may experience creep through the primary, secondary, and tertiary stages of rupture. 3.1.5 creep-rupture limit, n—the stress level below which creep rupture will not occur within a given time in a specified environment. See creep rupture. 3.1.6 durability, n—as related to adhesive joints, the endur- ance of joint strength relative to the required service condi- tions. (D907) 3.1.6.1 Discussion—Service conditions may include water and other chemicals, temperature, stress, radiation, microorganisms, and other environmental factors. 3.1.7 permanence, n—the resistance of an adhesive bond to deteriorating influences. (D907) 3.1.8 structural adhesive, n—a bonding agent used for transferring required loads between adherends exposed to service environments typical for the structure involved. (D907) 3.2 Definitions ofTerms Specific to This Standard: 3.2.1 allowable shear modulus, n—the modulus calculated in accordance with Section 14, that is used for the design of a structural joint. 3.2.2 basic shear modulus, n—the average shear modulus of 30 specimens fabricated and tested in accordance with 13.1.