Steel rod-reinforced plastic piling

Abstract

An elongated composite structural member having a cross-sectional area of at least 80 square inches includes a rigid cage having a parallel spaced plurality of main rod members in a circularly spaced array, the main rod members being formed steel reinforcing bars; a secondary rod member being a formed steel reinforcing bar having a plurality of helical loop elements contacting inwardly facing locations on each main rod member; and welded rigid connections being formed between the main rod members and the secondary rod member at not less than 30 percent of the contacting locations. A circularly cylindrical plastic body encapsulates and substantially solidly fills the rigid cage with the main rod members approximately equally spaced from an outside surface of the plastic body, wherein at least 90 percent by weight of the plastic body consists of a main polymeric component and an additive component, the main polymeric component consisting of low-density polyethylene of which at least 60 percent is linear low density polyethylene, the additive component including an effective amount of an ultraviolet inhibitor. In one preferred form having an outside diameter of 13 inches and an overall length of from 10 to 60 feet, the main rod members are approximately 1 inch diameter steel bars, the secondary rod member is an approximately 0.4 inch diameter formed steel reinforcing rod, the main rod members being spaced approximately ¾ inch within the outside diameter. Also disclosed is a method for forming a structural plastic member.

Dependencies are inferred from the claim text.