Use of recycled plastics for structural building forms

A bridge constructed from a modular thermoplastic structural member characterized by being an I-Beam comprising a web section disposed along a horizontal axis and one or more flange sections disposed along a horizontal axis parallel thereto and integrally molded to engage the top or bottom surface of said web section, wherein;

• the width of said flange sections measured perpendicular to said horizontal axis of said flange section is two to ten times the width of said web section measured perpendicular to said horizontal axis of said web section;
• the vertical dimension (thickness) of said flange sections are about one-tenth to about one-half the size of the vertical dimension of said web section without any flange sections;
• and said structural member is formed from a co-continuous immiscible polymer blend consisting essentially of
• a high density polyolefin and
• a thermoplastic polymer-coated fiber material or a thermoplastic polymer having fiber material embedded therein, wherein the bridge comprises a plurality of pier-supported parallel rows of larger first I-Beams, and a plurality of smaller second I-Beams disposed parallel to one another and fastened perpendicular to and between adjacent rows of the larger first I-Beams, wherein the top and bottom surfaces of the second I-Beam flanges are dimensioned to nest within the opening defined by the top and bottom flanges of the first I-Beams.