Polyurethane based roadway forming
Provided herein are roadways containing polyurethane materials. A roadway includes a base layer of a compacted in situ material and/or a wear layer disposed on the base layer. One or both of these layers may include the polyurethane material to bind other components in the layers and to form more robust and durable roadway structures capable of withstanding operating loads of the roadway. In some embodiments, the polyurethane material is added to the wear layer by mixing in situ soil and/or foreign aggregate with polyurethane material or by dispensing the polyurethane material over the existing partially formed wear layer. The base layer may or may not include a polyurethane material. The type, concentration, distribution, and processing of the polyurethane material in the wear layer may be the same or different than that in the base layer.
1. A roadway comprising:
a soil; and
a polyurethane material, dispersed in the soil thereby forming a polyurethane filled soil material,
wherein the polyurethane material is formed from a polyol and an isocyanate,
wherein the polyol comprises a chain extender, having a concentration of between about 1.0% by weight and 20% by weight of the polyol,
wherein a concentration of the polyurethane material in the polyurethane filled soil material is between about 2% by weight and 20% by weight, and
wherein the roadway is one of a road, a walkway, a base for railroad tracks, or a parking lot.
2. The roadway of claim 1 , further comprising a sealing layer disposed over the one or more layers formed by the polyurethane filled soil material.
3. The roadway of claim 2 , wherein the sealing layer comprises the polyurethane material.
4. The roadway of claim 1 , wherein the soil in the polyurethane filled soil material is a foreign aggregate comprises one of sand, gravel, or crashed rock.
5. The roadway of claim 1 , wherein the polyurethane filled soil material has a soil compaction of at least about 90%.
6. The roadway of claim 1 , wherein the concentration of the polyurethane material in the polyurethane filled soil material is between about 5% by weight and 10% by weight.
7. The roadway of claim 6 , wherein the pulverized in situ soil is a cured asphalt concrete composite.
8. The roadway of claim 6 , wherein the pulverized in situ soil is a bio-asphalt.
9. The roadway of claim 1 , wherein distribution of the polyurethane material in the polyurethane filled soil material is a non-uniform.
10. The roadway of claim 9 , wherein the concentration of the polyurethane material in the polyurethane filled soil material is greater at a top surface of the polyurethane filled soil material than at a bottom surface of the polyurethane filled soil material.
11. The roadway of claim 1 , further comprising a reinforcement component disposed within the polyurethane filled soil material.
12. The roadway of claim 11 , wherein the reinforcement component comprises a polymer other than the polyurethane material.
13. The roadway of claim 11 , wherein the reinforcement component enhances elasticity of the polyurethane filled soil material.
14. The roadway of claim 11 , wherein the polyol is polyethylene glycol (polyether polyol).
15. The roadway of claim 11 , wherein the polyurethane filled soil material is elastomeric.
16. The roadway of claim 1 , further comprising a reinforcement component disposed within the polyurethane filled soil material, wherein the reinforcement component comprises one of fumed silica, basalt fibers, silica fibers, glass fibers, or polypropylene fibers.
17. The roadway of claim 1 , further comprising a heat stabilizer disposed within the polyurethane filled soil material, wherein the heat stabilizer comprises one of aluminum hydroxide, magnesium hydroxide, antimony trioxide, antimony pentoxide, sodium antimonite, zinc borate, zinc stannate, zinc hydrostannate, red phosphorous, ammonium polyphosphate, or combinations thereof.
18. The roadway of claim 1 , wherein the roadway has an R-value of between about 15 and 60.
19. The roadway of claim 1 , wherein the chain extender is a polyolamine.
20. The roadway of claim 1 , wherein the chain extender is a triethylene tetraamine.