US 5,702,199 A · Plastic asphalt paving material and method of making same

Abstract

An asphaltic concrete or paving material includes from 5 to 20 percent or more of granular recycled plastic, which supplements or replaces the rock aggregate component of the mixture. The material produces a structurally superior paving material and longer lived roadbed. The paving material includes any and all residual classes of recyclable plastic, including thermosetting plastics and other plastics having little to no current widespread utility. The material produces roadbeds of higher strength with less total asphalt thickness and having greater water impermeability, and is most useful for all layers below the surface layer. The recyclable plastic component of the material is preferably a mixture of all recyclable classes 3 through 7, or of those materials from such classes from which potentially more valuable recyclable materials have been selectively removed. The paving product is preferably formed by a process of shredding or mechanically granulating used and industrial waste plastic to a no. 4 to 1/2 inch sieve size, and preferably to 1/4 inch to 3/8 inch granules. The granules are then treated with a reducing flame, with a plasma flame process, to activate the surface of the granules and increase the surface tension without raising the temperature of the plastic. The activated treated granules are then added to the aggregate and mixed with the asphalt to produce the paving material.

Claims30

Dependent claims

A roadway comprising:

a base gravel layer;
an asphaltic layer overlying the base layer and including:
an asphalt binder, and
an aggregate component, including rock aggregate and at least five percent by volume of particles of a plastic aggregate having treated activated surfaces, a major portion of the plastic aggregate being of a plastic material having a composition corresponding to one or more of PCCS classes 3 through 7;
and
the particles of plastic aggregate being made according to the process comprising the steps of:
mechanically reducing plastic material to granules, most of which are at least 1/8 inch in size;
and
treating the surfaces of the granules with an activating vapor at a temperature sufficiently low and for a time sufficiently short to avoid substantial melting, burning or other perceptible change to the surface of the granules, the treating step utilizing a vapor sufficiently active to activate the surfaces of the granules.

6 more elements

Dependencies are inferred from the claim text.

Plastic asphalt paving material and method of making same

Life of this patent

Plastic asphalt paving material and method of making same

Life of this patent

Abstract

Claims30