Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C23/00—Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or like surfaces
  • E01C23/06—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road
  • E01C23/065—Recycling in place or on the road, i.e. hot or cold reprocessing of paving in situ or on the traffic surface, with or without adding virgin material or lifting of salvaged material; Repairs or resurfacing involving at least partial reprocessing of the existing paving

Definitions

• the invention relates to a method for reasphalting a section of an asphalted road consisting of a base of base material and an asphalt coating which may comprise several layers of asphalt.
• the invention also relates to a reasphalting machine for reasphalting a section of an asphalted road consisting of a base of base material and an asphalt coating which may comprise several layers of asphalt, wherein the reasphalting machine comprises a mixing chamber for mixing existing asphalt with bitumen and possibly aggregate and solvents for the production of new asphalt material, and an asphalt-laying device for adding the new asphalt material to the road for the formation of a new asphalt coating.
• asphalted roads have to be reasphalted at intervals.
• the top layer of the asphalt coating in many cases is milled off before new asphalt is applied.
• Asphalt consists of bitumen, solvents and aggregate of varying size, usually in the form of different rock materials of a size varying from stone dust to crushed rock measuring between 10 and 20 mm.
• the quantitative ratio between aggregates of different sizes is laid down in standards.
• Roads are normally asphalted with asphalt which has a high percentage of large aggregate, since such asphalt is more hard-wearing than asphalt which has a high percentage of fine materials.
• asphalt should also be understood to include similar materials which are employed for road surfacing, particularly oil gravel.
• Milled-off asphalt can be recycled by heating it and mixing it with bitumen and possibly aggregate and solvents, or the milled-off asphalt can be mixed into the new asphalt material.
• a great deal of the aggregate is crushed and ground into fine materials, and thus there is a limit to how much milled-off asphalt can be used in the new asphalt material without the content of fine materials in the asphalt material becoming so high as to compromise the wear resistance of the finished asphalt coating. This complicates the production of the asphalt material, making recycling of milled-off asphalt unprofitable.
• the milled-off asphalt is instead driven to a dump site. From the environmental point of view, of course, this is undesirable.
• milling off asphalt is energy and time-consuming, and therefore from an economic point of view it is desirable to avoid this milling process.
• SE B 441 759 describes a reasphalting machine where asphalt which has been scaled or milled off in advance is collected in a channel and fed into a mixing chamber where it is mixed with new asphalt for subsequent application to the road, directly from the open bottom of the mixing chamber.
• SE B 447 586 describes a reasphalting machine where the existing asphalt coating is heated by microwaves in the front edge of the machine. Shredding bodies tear up the heated asphalt, whereupon the asphalt is passed up a channel by means of a screw and into a mixing chamber, where it is mixed with new asphalt. The finished asphalt is applied to the road through an opening in the rear edge of the mixing chamber.
• DE C2 3 739 294 describes a machine for producing a groove or a furrow in an asphalt surface, where a knife or a cutting implement is forced in under the asphalt surface by a hydraulic cylinder.
• a vibrator or rocking device gives the knife an alternating twisting movement in the vertical direction, with the result that the asphalt is forced up. Lateral edges ensure that the furrow has uniform edges.
• EP Al 0 324 491 describes a reasphalting machine where loose asphalt which is loosened in advance by a scraping process is collected by a collector in the front of the machine.
• the loose asphalt undergoes a cold process where water-based solvents are added to it, whereupon it is laid out on the road again as a new asphalt surface.
• the object of the invention is to provide a method and a reasphalting machine for reasphalting a section of an asphalted road, wherein existing asphalt can be employed in new asphalt material without this leading to an undesired high percentage of fine materials in the new asphalt material.
• the object is further to avoid energy and time-consuming milling-off of existing asphalt.
• a further object is to be able to employ the method for reasphalting and the reasphalting machine both when only one or more layers of the existing asphalt coating have to be removed before new asphalting, and when the entire existing asphalt coating has to be removed before new asphalting.
• the object is further to be able to repair and level the road's base in a rational manner before application of new asphalt material.
• a further object is to be able to reinforce the road's base before the application of new asphalt material.
• the object is further to be able to reasphalt the full width of a traffic lane in the road without impeding traffic in adjacent lanes.
• the core of the invention consists in existing asphalt being loosened from the road by the insertion of a cutting implement with a substantially horizontal front edge under the existing asphalt, thus loosening it as a whole.
• This existing asphalt is mixed with bitumen and possibly aggregate and solvents, thus producing a new asphalt material, which in turn is added to the base for the formation of a new asphalt coating.
• Asphalt coating may consist of one or more layers of asphalt, and according to the invention either the entire asphalt coating or only one or more of these layers may be loosened by the cutting implement.
• Fig. 1 is an elevational view of a reasphalting machine according to the invention.
• Fig. 2 is a top view of the reasphalting machine in fig. 1.
• Fig. 3 is an elevational view of a cutting implement which is employed in the invention, during loosening of an entire asphalt coating.
• Fig. 4 is an elevational view of the cutting implement in fig. 3, used when loosening one layer of an asphalt coating.
• Figs. 1 and 2 illustrate a reasphalting machine according to the invention for reasphalting a section 2 of an asphalted road 1.
• the section which has to be asphalted constitutes one traffic lane.
• a lorry 20 which does not form part of the invention, and which will be discussed in more detail later. Then follows an intake 22 for supply of new asphalt material and new base material, which will also be discussed in more detail later.
• a cutting implement 9 with a substantially horizontal front edge 15 for loosening existing asphalt from the road.
• the asphalt is loosened as a continuous layer or coating 5, which will be discussed in more detail later, and is pressed slidingly up the cutting implement 9 to a breaking unit 12, illustrated as a wheel with four wings.
• a breaking unit 12 illustrated as a wheel with four wings.
• the asphalt coating 5 is broken up into smaller pieces, and falls down on to a transport track 17 in the form of a conveyor belt, which passes the asphalt to a heating unit 13.
• the asphalt is heated by a combination of microwaves and heat from diesel combustion.
• the electricity which is used in the microwave heating is generated by diesel-driven electric units 31 , placed on supports 33 in the machine's rear portion. At the same time surplus heat from the diesel combustion is also used for heating the asphalt, thus achieving a high energy utilisation.
• the asphalt pieces may be heated directly by flames from diesel combustion.
• the hot asphalt is passed via a transporter 24 to a mixing chamber 25, where it is mixed with bitumen from tank 27 supported by a frame 48, thus producing a new asphalt material which can be employed in asphalting the road.
• a mixing chamber 25 where it is mixed with bitumen from tank 27 supported by a frame 48, thus producing a new asphalt material which can be employed in asphalting the road.
• aggregate and solvents may also be added.
• As aggregate a base material may be used, which will be discussed in more detail later, which is supplied via a transporter 26 from a storage tank 40. Solvents may be added from a not shown solvent tank.
• the asphalt material is passed by means of a transporter 46, illustrated as a conveyer belt, to an asphalt-laying device 41 in the rear edge of the machine, where the asphalt material is indicated by reference numeral 10.
• the asphalt material is laid on the road in the known manner, and the laid asphalt is rolled by a roller 34 to form a finished new asphalt coating 11.
• Fig. 3 illustrates the cutting implement 9 in closer detail, while simultaneously illustrating the construction of the road 1 and the location of the cutting implement relative thereto corresponding to figs. 1 and 2.
• the road in fig. 3 consists at the bottom of underlying materials 19, which may consist of coarse stones. On top of these underlying materials 19 the road consists of a base 3 of base material 4, which may typically be stones measuring 10 to 20 mm, and on top of this an asphalt coating 5.
• the cutting implement 9 is composed of a substantially flat plate, extending over the entire width w of the area which has to be reasphalted. As the reasphalting machine advances in the direction P 1 the front edge 15 of the cutting implement is disposed at a level between the asphalt coating 5 and the base 3, and the cutting implement 9 is tilted in the direction backwards and upwards. The front edge 15 of the cutting implement is forced in between the asphalt coating 5 and the base 3, thus causing the asphalt coating 5 which is located above the cutting implement to be loosened from the base 3 as a whole, and pressed slidingly up the cutting implement 9.
• the upper portion of the cutting implement is rotatably attached to a bracket 42 by means of a rotating joint 44, and the bracket 42 in turn is welded to the support frame 32.
• the cutting implement 9 In its central area or lower portion the cutting implement 9 is connected to a hydraulic cylinder 29, which is connected via a rotating joint 45 and a bracket 43 to the support frame 32.
• a hydraulic cylinder 29 By means of not shown measuring and control devices the front edge 15 of the cutting implement can be adjusted by means of the hydraulic cylinder 29 to the correct level between the asphalt coating 5 and the base 3.
• Fig. 3 also illustrates a cutting device 16 disposed in front of the cutting implement 9, at the part of the cutting implement's outer edge which faces in towards the middle of the roadway.
• the cutting device 16 is composed of a wheel which by means of a not shown device is pressed so far down into the roadway that along the centre line of the road a through-going groove 47 is produced in the existing asphalt coating 5, see fig. 2.
• the reasphalting area 2 thereby obtains a uniform edge, which facilitates the laying of new asphalt and ensures a smooth transition between the reasphalting area and the rest of the roadway.
• the base 3 is exposed, as illustrated in figs. 1 and 3.
• the base On account of setting and the influence of water and temperature the base will often be uneven, and may have cavities 14, see fig. 1.
• scrapers which in the illustrated embodiment are three in number and are indicated by reference numerals 35, 36 and 37.
• the scrapers are tilted in a zigzag pattern, and displaced relative to one another in the direction of the reasphalting machine's width, see fig. 2.
• the base is first levelled by the front scraper 35.
• the front scraper simultaneously picks up existing base material 4 (see fig. 1) and, due to its tilted position, the front scraper 35 passes the base material up towards one side of the reasphalting machine. At the end of the front scraper 35 the base material 4 leaves the scraper and is picked up by the middle scraper 36, which continues the levelling of the base and passes the base material 4 out towards the other side of the reasphalting machine, where it leaves the middle scraper 36.
• the rear scraper 37 picks up the base material and completes the scrapers' levelling of the base.
• the reasphalting machine also includes a spreading box 38 located behind the rear scraper 37, for laying out new base material 18.
• the new base material 18 is added from the storage tank 40, which was mentioned in connection with the heating unit 13. Cavities 14 in the base which have not been filled by the levelling of the scrapers are filled with new base material 18 from the spreading box 38.
• the scrapers 35, 36 and 37 and the spreading box 38 thereby provide a rational repair and levelling of the road's base before application of new asphalt material.
• the spreading box 38 may also be used for laying out a layer of new base material in order to reinforce the road's base before the application of new asphalt material. Behind the spreading box 38 there is located a compactor 39, which compacts the base 3 and increases its firmness prior to asphalting with the asphalt-laying device 41, which is located at the back of the machine.
• the cutting implement 9, the scrapers 35, 36 and 37, the spreading box 38, the compactor 39 and the asphalt-laying device 41 are vertically movable and are controlled by not shown control devices.
• the spreading box and the asphalt-laying device may also have capacity regulation.
• the level as well as any unevenness in the existing asphalt coating and the base, and the level of the new asphalt coating are measured by suitable measuring equipment, such as vertically movable measuring wheels placed in the front and rear edges of the machine and between the cutting implement 9 and the front scraper 35.
• suitable measuring equipment such as vertically movable measuring wheels placed in the front and rear edges of the machine and between the cutting implement 9 and the front scraper 35.
• laser technology may advantageously be employed.
• the read-off measured values are used as the basis for control of the cutting implement, the scrapers, the spreading box, the compactor and the asphalt-laying device in order to obtain correct height of the cutting implement, application of the desired amount of new base material, desired evenness and firmness of the base, thickness of the new asphalt coating and levelness and height of the new asphalt coating's surface.
• the intake 22 is in the form of a carriage with a box or container, and receives when required a supply of new asphalt material or new base material from a loading area 21 on the lorry 20.
• a transport track 23 in the form of a conveyor belt which is located above the cutting implement 9 passes the new asphalt material or the new base material from the box or the container 22 to a rotatable transporter 30 located beside the storage tank 40.
• the transporter 30 is directed towards the storage tank 40, and the new base material, indicated by reference numeral 18, is passed down into the storage tank.
• the transporter is directed towards the asphalt-laying device 41, as illustrated in fig. 2, and the new asphalt material, indicated by reference numeral 10, is thereby passed to the asphalt-laying device.
• Fig. 4 illustrates the cutting implement 9 in use on a road where the asphalt coating consists of several layers of asphalt, indicated by reference numerals 6, 7, 8, and where only the top asphalt layer 8 requires to be removed.
• the front edge 15 of the cutting implement is here disposed at a level between the top asphalt layer 8 and the second top asphalt layer 7.
• the adhesion between two asphalt layers is not so great as to prevent the layers from sliding apart when the cutting implement 9 is forced in between the layers, while at the same time the internal adhesion in each of the layers is strong enough to hold the asphalt together.
• the top asphalt layer 8 is thereby loosened from the second top asphalt layer 7 as a whole, and is pressed up the cutting implement 9 in a substantially continuous layer.
• the scrapers, the spreading box and the compactor can also be employed when the reasphalting machine is used for this purpose if there are cavities in the underlying asphalt layers 6, 7.
• a method and a reasphalting machine for reasphalting a section of an asphalted road where existing asphalt is used in the new asphalt material without employing energy and time-consuming milling.
• the aggregate in the existing asphalt is thereby not exposed to crushing and grinding into fine materials as is the case with milling, and the new asphalt material thereby does not acquire an undesired high percentage of fine materials.
• the area being reasphalted may have any desired width.
• the area has a width corresponding to one traffic lane, and since new asphalt material and new base material are supplied from the lorry located in front of the reasphalting machine, the reasphalting machine according to the invention can be employed for reasphalting the full width of a traffic lane of a road without impeding the traffic in adjacent lanes.

Landscapes

• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Road Repair (AREA)
• Road Paving Structures (AREA)
• Road Paving Machines (AREA)
• Disintegrating Or Milling (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19901682

Family Applications (1)

Country Status (4)

Cited By (4)

Families Citing this family (1)

Citations (8)

• 1998
  • 1998-02-16 NO NO19980650A patent/NO310836B1/no not_active IP Right Cessation
• 1999
  • 1999-02-16 CA CA002321062A patent/CA2321062A1/en not_active Abandoned
  • 1999-02-16 AU AU28629/99A patent/AU2862999A/en not_active Abandoned
  • 1999-02-16 WO PCT/NO1999/000050 patent/WO1999041456A1/no active Application Filing

Patent Citations (8)

Also Published As

Similar Documents

Legal Events