ASTM International

Standard Specification for Polyethylene-Based Structural-Grade Plastic Lumber for Outdoor Applications
 N D7568

Annotation

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.

This specification is applicable to solid, rectangular SGPL products where polyethylene resin (non cross-linked) is the continuous phase and is at least 50 % of the product (by weight).

This specification is not applicable to plastic lumber products containing cellulosic materials as additives, fillers or fiber reinforcements.

SGPL products covered by this specification shall not be used as tensile members.

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.

Due to thermodynamic effects that result in outersurface 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.

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.