Composite load bearing structure

Claim 1

A composite load bearing structure comprising: a main body portion having a top surface and a bottom surface defining a dimension of thickness therebetween, first and second-side surfaces defining a dimension of width therebetween, first and second end surfaces defining a dimension of length therebetween, and a first longitudinal axis oriented along the length of said main body portion; wherein said dimension of thickness is significantly less than at least said length of said load bearing structure; wherein said main body portion is made of a first composite material comprising a binding constituent in a proportion of about 10% to about 20% by volume, and an aggregate material in a proportion of about 80% to about 90% by volume; wherein said binding constituent in said main body portion comprises a plastic material chosen from the group consisting of polyethylene and a polyethylene blend having at least 10% polyethylene; wherein said aggregate material is in the form of irregular multi-faceted pieces chosen from the group consisting of crushed furnace slag, crushed gravel, crushed limestone, crushed granite, crushed basalt, crushed trap rock, and mixtures thereof; and wherein the pieces of said aggregate material are distributed and otherwise arranged within said main body portion so that opposed surfaces of said pieces of aggregate material have at least partial contact, one with another, in a contiguous manner; and at least one inner strengthening member having a second longitudinal axis which is substantially parallel to said first longitudinal axis; wherein said at least one inner strengthening member is chosen from the group consisting of reinforcing bars; rolled, drawn, or cast ferrous sections; rolled, drawn, or cast composite alloy sections; plastic, metallic, and carbon based fibers; wire mesh, and expanded metal mesh.