Coating processes – Coating pavement or the earth – Asphalt – bitumen – oil – or tar containing coating
Reexamination Certificate
1999-02-22
2001-06-19
Szekely, Peter (Department: 1714)
Coating processes
Coating pavement or the earth
Asphalt, bitumen, oil, or tar containing coating
C427S136000, C524S059000, C524S060000, C524S062000
Reexamination Certificate
active
06248396
ABSTRACT:
TECHNICAL FIELD
The present invention generally relates to asphalt compositions. In particular, the present invention relates to asphalt compositions useful for paving surfaces, methods of paving surfaces using the asphalt compositions, asphalt compositions useful as a stress absorbing layer between old and new pavement surfaces, and asphalt pavement having a surface that flexes.
BACKGROUND OF THE INVENTION
Road pavements are made with maximum strength. Consequently, aggregate incorporated into road pavements is hard aggregate. Asphalt is no exception. Hard aggregate used in asphalt includes sand, rocks, pebbles, gravel, glass and stone. While hard aggregate increases the maximum strength of asphalt, hard aggregate also increases sturdiness or inflexibility of asphalt. A pavement characterized by sturdiness and inflexibility is not desirable in all instances. Therefore, new asphalt pavements are desired.
A new asphalt surface is in some instances conventionally applied to an old asphalt surface in need of resurfacing. Typically, this is because the old asphalt surface exhibits cracks. This phenomenon is sometimes termed reflective cracking. One reason for this phenomenon is that asphalt is a relatively brittle material, and over time, various stresses imposed on an asphalt surface induce the formation of cracks. Accordingly, old asphalt surfaces are simply repaved with a new asphalt layer. However, the new asphalt layer tends to exhibit cracks, often in the same places where the old, underlying asphalt layer exhibited cracks.
In an attempt to solve this problem, a membrane is used between the old and new layers of asphalt. There are two types of conventional membranes; namely, a layer of a liquid binder embedded with a hard aggregate material (shot and chip) and a fabric layer. Conventional membranes function by exerting tension on the old, underlying asphalt layer so as to prevent the old, underlying asphalt layer from moving (exerting force). New asphalt surfaces applied over a convention membrane which is turn applied over an old asphalt surface continue to exhibit cracking. New and improved methods of repaving cracked asphalt surfaces and/or new and improved materials for repaving cracked asphalt surfaces are desired.
SUMMARY OF THE INVENTION
The present invention provides asphalt compositions which minimize the use of undesirable organic solvents. The present invention also provides asphalt compositions which are strong and durable yet flexible. As a result, the dangers associated with ice formation on pavements made with the asphalt compositions of the present invention used on the surface are minimized and/or eliminated. Also as a result, stresses and forces are absorbed rather than transferred by the pavements made with the asphalt compositions of the present invention used on an interlayer. The present invention provides asphalt compositions which effectively channel water. As a result, the dangers associated with hydroplaning and skidding on pavements made with the asphalt compositions of the present invention are minimized and/or eliminated.
In one embodiment, the present invention relates to an asphalt composition for paving surfaces to accommodate motorized vehicles containing from about 5% to about 97% by weight asphalt; from about 1% to about 50% by weight of a terpenoid liquid; from about 1% to about 50% by weight of a rubber polymer; and from about 1% to about 98% by weight of a flexible aggregate, wherein a resultant asphalt pavement made with the asphalt composition which is at least ¼ inch in thickness flexes at least about {fraction (1/1000)} of an inch by a force greater than about 22 lbs/in
2
.
In another embodiment, the present invention relates to a method of paving a surface to accommodate motorized vehicles comprising providing a mixture comprising: asphalt; a terpenoid liquid; a rubber polymer at least partially soluble in the mixture; and flexible aggregate; and applying the mixture to a surface, wherein a resultant asphalt pavement made with the mixture which is at least ¼ inch in thickness is flexes at least about {fraction (1/1000)} of an inch by a force greater than about 22 lbs/in
2
.
In yet another embodiment, the present invention relates to a method of paving a surface involving the steps of providing a mixture containing asphalt; a terpenoid liquid; and a rubber solid at least partially soluble in the mixture; applying the mixture to a surface; applying flexible aggregate to the mixture covered surface to form a stress absorbing layer; applying an asphalt composition comprising asphalt and hard aggregate to the stress absorbing layer.
In still yet another embodiment, the present invention relates to a method of paving a surface involving the steps of providing a mixture containing asphalt, a terpenoid liquid, a rubber solid and flexible aggregate; applying the mixture to a surface to form a stress absorbing layer; applying an asphalt composition comprising asphalt and hard aggregate to the stress absorbing layer.
REFERENCES:
patent: 3919148 (1975-11-01), Winters et al.
patent: 4166049 (1979-08-01), Huff
patent: 4217259 (1980-08-01), Bresson
patent: 4412019 (1983-10-01), Kraus
patent: 4835199 (1989-05-01), Futamura et al.
patent: 4973615 (1990-11-01), Futamura et al.
patent: 5710196 (1998-01-01), Willard
Brzozowski, Kenneth, “Asphalt vs. Coal Tar”, Jul. 1990, pp. 26-37.
Renner, Otto, Boiselle & Sklar LLP
Szekely Peter
LandOfFree
Asphalt compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Asphalt compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Asphalt compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2506168