Asphalt (and other surface pavement materials such as macadam and tarmac) covers many surfaces such as roadways, runways and parking lots. Over time, wear and tear from vehicle traffic, weather, and oxidation, occurs and leads to cracks, bumps, dips, ruts and other irregularities in the asphalt. These unwanted formations are both an eyesore and a safety hazard that is dangerous to traffic.
There are a number of ways to refinish asphalt surfaces and to remove the unwanted irregularities. For example, a common method for repairing damaged asphalt includes removing the damaged asphalt from a surface and replacing it with new asphalt. The old asphalt is discarded and new asphalt material is used to refinish the surface. While this method is effective in renewing damaged asphalt surfaces, it is neither cost efficient nor environmentally friendly.
To address environmental and cost issues, systems have been developed that recycle at least a portion of the removed asphalt and reapply it to the refinished surface. These systems reduce material costs, eliminate waste and dumping costs, and are more environmentally conscious. These systems, however, do not effectively break up, remove, and reuse all existing asphalt and still typically requires the use of new asphalt.
One method of recycling and reapplying asphalt is Hot In-Place Recycling (“HIR”). Unlike cold recycling methods, HIR involves a first step of heating the damaged asphalt to soften the upper layer to a predetermined depth. Exemplary methods of heating asphalt are disclosed in U.S. Pat. No. 3,970,404. The heated layer of damaged asphalt is then removed through a scarification process. Commonly, between one and two inches of the top layer is removed during scarification. The removed asphalt is fed to a mixer that sifts out large, unusable pieces of asphalt, leaving only small, workable pieces. New material or reconditioning agents may be added to the reclaimed asphalt during the mixing process. The combination of old material and new additives is heated to enhance blending. The new mixture is then reapplied to the surface and compacted and smoothed by a steamroller while the surface is still hot.
HIR is an effective method for recycling damaged asphalt. However, several limitations exist in traditional HIR methods. One drawback is that multiple separate machines are traditionally required to perform the HIR process, including heating machines, scarifying machines, repaving machines and smoothing machines. The multiple machines increase both time and cost of repaving jobs. Another drawback is that the process of recycling and repaving asphalt is very slow, often moving at speeds of less than 10 feet per minute. Further, HIR is an inferior system for removing and reclaiming the damaged asphalt and requires more additives for the recycled asphalt. Thus, a need exists for an improved method and system for recycling and reapplying asphalt.
An apparatus for repaving an asphalt surface is provided. The apparatus includes a base carried on a plurality of wheels and a center mill connected to the base. The center mill may include a plurality of teeth members to break up the asphalt surface and a plurality of lip members and paddles to lift the broken asphalt.
In an embodiment the apparatus includes additional components to assist in reconditioning the asphalt surface. For example, the apparatus may include a heater to heat and soften the damaged asphalt surface. The apparatus may further include a series of circular blades to scarify the asphalt surface and funnel broken asphalt towards the center mill. A mixer may be connected to the base to receive reclaimed asphalt and recondition the reclaimed asphalt to be reapplied to the surface.
Objects and advantages together with the operation of the invention may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein:
An apparatus and method for reconditioning and recycling an asphalt surface is provided. The apparatus 10, as illustrated in
The base 12 may include a plurality of frame structures connected together. For example, the base 12 may include a first frame structure connected to a second frame structure as shown in
The frame structures may be connected by an articulation pin 14. (
The apparatus 10 also include a plurality of wheels 24. For example, the apparatus 10 may include two front wheels 24 and two rear wheels 24. The apparatus 10 may alternatively include two front wheels 24 and four rear wheels 24. (
The apparatus 10 may include a wheel lift 26 connected to one or more wheels 24 to adjust the distance between the base and the asphalt surface. (
The apparatus 10 includes a heater 36 connected to the base. (
The apparatus 10 includes a series of blades 48 for scarifying the heated asphalt surface. (
The blades 48 may be configured to channel the dislodged asphalt towards the center of the apparatus 10. For example, the circular blades 48 may be spirally connected around the blade axis 49 and configured to rotate about the blade axis 49. The rotating spiral blades 48 push dislodged asphalt towards the center of the apparatus 10. The apparatus 10 may include two series of blades 48. The blades 48 may be arranged at an angle to funnel the dislodged asphalt towards the center of the apparatus 10. For example, the portion of the blades 48 adjacent to the cylinder 51 may be positioned towards the front of the apparatus 10 and the portion of the blades 48 near the center of the apparatus 10 may be positioned towards the rear of the apparatus 10. This angled configuration allows the dislodged asphalt to be funneled towards the center of the apparatus 10.
The apparatus 10 includes a center mill 52 for breaking up the dislodged asphalt. (
The teeth members 54 may be arranged in a spiral row configuration along the mill body 53. (
The center mill 52 is configured to rotate onto the asphalt surface. For example, the mill body 53 may be generally cylindrical in shape and configured to rotate about its axis. However, it will be appreciated that the mill body 53 may also be any shape capable of rotating with respect to the asphalt surface. The center mill 52 may further be configured to receive scarified asphalt from the blades 48. For example, as the center mill 52 rotates, the teeth members 54 may crush heated asphalt into small pieces. The lip members 56 and center paddles 58 may lift the crushed asphalt and deliver it to other components of the apparatus 10, such as a conveyor (not shown) to be sifted and treated.
The center mill 52 may be connected to a mill box 60. (
The mill box 60 may be open on at least one side to partially expose the center mill 52. The mill box 60 may be connected to the base 12 and configured such that an open side of the mill box 60 faces the asphalt surface, allowing the center mill 52 to receive scarified asphalt from the blades 48.
The apparatus 10 includes a mixer 66 for reconditioning the reclaimed asphalt. (
In use, the apparatus 10 moves over the asphalt surface to be refinished. The heater 36 applies heat to soften a top layer of asphalt. Blades 48 engage the asphalt surface to lift and dislodge the heated layer of asphalt. The blades 48 feed the dislodged asphalt to the center mill 52. The teeth members 54 of the rotating center mill 52 also lift and dislodge the asphalt and further break up the asphalt into small pieces. The lip members 56 and center paddles 58 receive the dislodged asphalt and feed it into the mixer 66. The trommel inside the mixer 66 separates small workable pieces of reclaimed asphalt from larger, unworkable pieces of reclaimed asphalt. The mixer 66 also mixes the reclaimed asphalt with a composition such as an emulsifier. The reclaimed asphalt may be further heated, and reconditioning agents or new material may be added. The reconditioned asphalt is deposited from the mixer 66 back onto the milled surface. Typical systems and methods such as steamrolling, compaction, or other rolling means may be used to smooth out and compact the reconditioned asphalt.
The invention has been described with reference to the embodiments. Obviously, modifications and alternations will occur to others upon a reading and understanding of this specification. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claim or an equivalent thereof.
This application claims benefit from U.S. Provisional Patent Application No. 61/192,757, entitled “Apparatus for Recycling Asphalt,” filed on Sep. 22, 2008, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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61192757 | Sep 2008 | US |