ASTM D3535-07a(R2021) pdf free download

ASTM D3535-07a(R2021) pdf free download.Standard Test Method for Resistance to Creep Under Static Loading for Structural Wood Laminating Adhesives Used Under Exterior Exposure Conditions
1. Scope
1.1 This test method covers adhesives suitable for the bonding of wood, including treated wood, into structural laminated wood products for general construction, for marine use, or for other uses where a high-strength general construction, creep-resistant, waterproof adhesive bond is re- quired. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.4 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 glulam, n—synonym for structural-glued-laminated timber. 3.1.2 structural-glued-laminated timber, n—an engineered, stress-rated product of a timber laminating plant comprising assemblies of specially selected and prepared wood lamina- tions securely bonded together with adhesives, with the fol- lowing characteristics: (1) the grain of all laminations is approximately parallel longitudinally; and (2) the laminations may be comprised of pieces end-joined to form any length, of pieces placed or glued edge-to-edge to make wider ones or of pieces bent to curved form during gluing. (Synonym glulam) ANSI/AITC A190.1 – 2002, American National Standard for Wood Products—Structural Glued Laminated Timber (Edited to conform with ASTM format). 3.1.3 For other terms used in this test method, refer to Terminology D907.
7. Selection and Preparation of Wood
7.1 Use any softwood or hardwood planned for gluing. Only one species is required, even if several will be glued. Flat- grained wood is most desirable, however experience has shown that flat-grained specimens may break in the wood when loaded. (This test measures only creep. Use Specification D2559 to measure bondability to all species considered.) 7.2 The wood shall have a slope of grain not steeper than 1 in 15 on any face or any edge. The wood shall contain no knots larger than 3.18 mm ( 1 ⁄ 8 in.) in diameter and shall be free of decay, machining defects (such as chipped grain, dubbed ends, feed roll polish, coarse knife marks, and feed roll compression), and any drying defects such as case hardening, collapse, splits, or checks. 7.3 Condition the wood at 23 6 2°C (73.4 6 3.6°F) and a relative humidity of 50 to 70 % (preferably 65 %) until a moisture content of8 to 14 % or, preferably, 9 to 12 % has been obtained.7.4 Freshly knife plane each lamination before applying the test adhesive. The machining tolerances for each lamination used in preparing the test specimen shall be no greater than 60.25 mm (0.01 in.) between laminations and 60.20 mm (0.008 in.) within laminations. Observe the most severe of the above tolerances.
8. Test Specimens
8.1 The laminated wood members shall be prepared from boards 15.9 mm ( 5 ⁄ 8 in.) thick by 63.5 mm (2 1 ⁄ 2 in.) wide by 304.9 mm (12 in.) along the grain for each test condition. Each test lamination shall be made from two outer laminations as above and alternate metal spacers and wood sections for the inner lamination (Fig. 3). The wood sections shall be sliced from a third board identical to that above. The wood sections shall be 28.5 mm (1 1 ⁄ 8 in.) along the grain by 15.9 mm ( 5 ⁄ 8 in.) thick by 63.5 mm wide. The laminated wood members shall be prepared by alternately laying seven metal spacers on edge tightly adjacent to eight wood center sections. The wood sections should be slightly thicker than the metal spacers to obtain adequate pressure on the gluelines. It has been found that running a 13-mm ( 1 ⁄ 2 -in.) piece of tape completely around the 16 loose pieces holds them together as a unit while gluing. Glue should be applied to the outer laminations and not the center ply. The outer laminations shall then be applied over- lapping about 13 mm on each end and the entire assembly carefully clamped and the adhesive cured as recommended. After curing and clamp removal, the metal spacers shall be pushed gently (not impact driven) out.