Active Standard ASTM D7568 | Developed by Subcommittee: D20.20
Book of Standards Volume: 08.03
Historical (view previous versions of standard)
1.1 This specification covers a type of plastic lumber product, defined as polyethylene-based structural-grade plastic lumber (SGPL), for use as main framing members, including joists, stringers, beams, columns; and secondary framing members, including planking, posts and bracing; in outdoor structures such as decks, boardwalks, docks, and platforms.
1.5 SGPL products are produced using several different manufacturing processes. These processes utilize a number of polyethylene resin material systems that include varying proportions of fillers, fiber reinforcements, and other chemical additives.
1.6 Due to thermodynamic effects that result in outer-surface densification during manufacture, SGPL products are typically non-homogeneous in the cross-section. This standard does not address materials that have been modified from their original cross-section.
1.6.1 The cross-section non-homogeneity is addressed in the material property assessments in this document only for applications in which the product cross-section is not modified by cutting, notching, or drilling. For products modified in this manner, additional engineering considerations are required and they are beyond the scope of this document.
1.7 For purposes of this standard, an SGPL product is a specific combination of polyethylene resin, together with fillers, reinforcements, and additives. Each formulation is to be identified as a distinct and different product, to be tested and evaluated separately.
1.10 A wide variety of chemical additives are typically added to SGPL formulations. Examples include colorants, chemical foaming agents, ultraviolet stabilizers, fire retardants, lubricants, anti-static products, heat stabilizers, and coupling agents.
1.11 Diverse types and combinations of filler systems are permitted in the manufacturing of SGPL products. Fillers that cause the product to fail the requirements of 6.13 are not permitted in the manufacturing of SGPL products.
1.12 In order for a product to be classified as SGPL, it must meet the minimum stress and modulus criteria consistent with the specific product as marked, and additionally the properties specified in Section 6 of this specification.
1.13 This specification pertains to SGPL where any reinforcement is uniformly distributed within the product. When reinforcement is not uniformly distributed, the engineering issues become substantially more complex. For this reason, such products are not covered in this document.
1.14 Products that fail at strains of less than 0.02 (2 %) when tested in flexure in accordance with 6.6 are not compatible with the underlying assumptions of Annex A1 and are beyond the scope of this standard (see Note 1).
1.19 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D883 Terminology Relating to Plastics
D2344/D2344M Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates
D2915 Practice for Sampling and Data-Analysis for Structural Wood and Wood-Based Products
D6108 Test Method for Compressive Properties of Plastic Lumber and Shapes
D6109 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products
D6112 Test Methods for Compressive and Flexural Creep and Creep-Rupture of Plastic Lumber and Shapes
D6341 Test Method for Determination of the Linear Coefficient of Thermal Expansion of Plastic Lumber and Plastic Lumber Shapes Between -30 and 140F (-34.4 and 60C)
D6662 Specification for Polyolefin-Based Plastic Lumber Decking Boards
D7032 Specification for Establishing Performance Ratings for Wood-Plastic Composite Deck Boards and Guardrail Systems (Guards or Handrails)
E84 Test Method for Surface Burning Characteristics of Building Materials
Other DocumentsASCE 7 Minimum Design Loads for Buildings and Other Structures Available from American Society of Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http://www.asce.org.
ICS Number Code 83.140.01 (Rubber and plastic products in general)