Compositions and methods for the introduction of elastomeric reinforcement fibers in asphalt cement concrete
The present invention relates to elastomeric polymer fiber reinforced asphalt cement concrete for use in a variety of applications. In particular, the reinforcement fibers are effective to reduce or preclude voids and/or cracks formed in the asphalt upon placement and to render a self-healing property to the placed asphalt.
1. A fiber-reinforced asphalt composition, comprising:
asphalt; and
a plurality of reinforcement fibers composed of elastomeric polymer, and absent of material selected from the group consisting of ground rubber tire, tire aggregate and tire particulate,
wherein the elastomeric polymer is a recycled material.
2. The asphalt composition of claim 1 , wherein the elastomeric polymer comprises synthetic polymer containing polyurethane.
3. The asphalt composition of claim 2 , wherein the elastomeric polymer comprises spandex.
4. The asphalt composition of claim 1 , wherein the plurality of reinforcement fibers has an aspect ratio from about 20 to about 5000, a denier from about 20 to about 1500, and a length from about 1/16-inch to about 3 inches.
5. The asphalt composition of claim 1 , wherein the elastomeric polymer is selected from the group consisting of natural polyisoprene and synthetic polyisoprene.
6. The asphalt composition of claim 1 , wherein the elastomeric polymer is selected from the group consisting of polybutadiene, chloroprene rubber, polychloroprene rubber, butyl rubber, styrene-butadiene rubber, nitrile rubber and mixtures thereof.
7. The asphalt composition of claim 1 , wherein the elastomeric polymer is selected from the group consisting of ethylene propylene rubber, ethylene propylene diene rubber, epichlorohydrin rubber, polyacrylic rubber, silicone rubber, fluorosilicon rubber, fluoroelastomers, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylene-vinyl acetate and mixtures thereof.
8. The asphalt composition of claim 1 , wherein the reinforcement fibers are in the form of individual fibers, one or more bundles, one or more containers and combinations thereof.
9. The asphalt composition of claim 1 , wherein the fiber-reinforced asphalt composition further comprises non-elastomeric reinforcement fibers.
10. The asphalt composition of claim 9 , wherein the non-elastomeric reinforcement fibers are selected from the group consisting of polyolefin fibers, aramid fibers, and mixtures thereof.
11. The asphalt composition of claim 9 , wherein the plurality of reinforcement fibers composed of elastomeric polymer serve as a carrier for the non-elastomeric reinforcement fibers.
12. A fiber-reinforced asphalt, comprising:
asphalt cement;
a plurality of reinforcement fibers composed of elastomeric polymer, and absent of material selected from the group consisting of ground rubber tire, tire aggregate and tire particulate; and
aggregate,
wherein the elastomeric polymer is a recycled material, and
wherein the plurality of reinforcement fibers promotes healing of cracks formed within field-placed fiber-reinforced asphalt.
13. The asphalt of claim 12 , wherein said reinforcement fibers have an ability in the field-placed fiber-reinforced asphalt to stretch beyond their original shape and then to subsequently resume their original shape to heal cracks.
14. A method of preparing fiber-reinforced asphalt, comprising:
providing asphalt;
providing aggregate;
providing a plurality of reinforcement fibers composed of elastomeric polymer, and absent of material selected from the group consisting of ground rubber tire, tire aggregate and tire particulate; and
introducing and distributing the reinforcement fibers into the aggregate in the asphalt to produce the fiber-reinforced asphalt,
wherein the elastomeric polymer is a recycled material.