Paving machine and pavement edger therefor

Information

  • Patent Grant
  • 6238136
  • Patent Number
    6,238,136
  • Date Filed
    Friday, July 16, 1999
    25 years ago
  • Date Issued
    Tuesday, May 29, 2001
    23 years ago
Abstract
A paving machine and pavement edger therefor are provided. The pavement edger is capable of creating a stepped tapered ramp having a highly compacted step and a highly compacted upper portion of the tapered portion. The resulting ramp allows for safety during pavement laying work stoppage and creation of solid pavement joints.
Description




BACKGROUND OF THE INVENTION




1. Technical Field




The present invention relates generally to paving and, more particularly, to a paving machine and pavement edger therefor.




2. Related Art




Typically, screed pavers include a self-propelled paving machine having a hopper for receiving paving material, e.g., asphalt, from a truck so that the truck progressively dumps its load of paving material into the hopper. A conveyor system on the paving machine transfers paving material from the hopper rearwardly for discharge onto the roadbed in front of transversely arranged screw augers which spread the material laterally in front of a main screed. This main screed functions to compress and level the paving material distributed by the augers to give a smooth finished road surface. The height and attack angle of the main screed may be varied to control the depth and surface of the pavement mat. The main screed may also include screed extenders to allow for a wider pavement mat to be laid.




One of the problems in paving of multiple lanes, especially on high speed interstate highways, is the drop off at an edge of a new pavement mat. During paving operations, it is oftentimes impossible to pave two lanes in a short time span due to a variety of reasons, e.g., traffic, equipment shortages, etc. One reason, in particular, is time constraints caused by the paving crew having to back up and start the second or closure pass on a two lane paving operation at mid-day. Where more than two lanes are being paved, the paving crew must back up at least twice during the day to minimize drop off length on both lanes being paved. Despite the drop off problem, it has become common practice for paving crews to pave only a single lane during one paving day to avoid having to back up. The entire length of this pass therefore becomes a drop off. Where an edge must be left overnight, a drop off of up to 1½ inches has not been considered objectionable for a short distance.




While a drop-off is usually only an overnight or weekend problem, it creates safety problems such as: vehicle wheels becoming caught on the drop off during lane changes onto or from the new mat, and loose stones/aggregate being kicked up by vehicles. In response to these safety problems, federal and some state highway contracting regulations are now mandating that any drop off between a new pavement mat and any adjacent material, e.g., un-repaved asphalt, shall not have a height over one inch unless a paved ramp is provided from/to the new pavement mat. Because it is often highly undesirable to lay a new layer of pavement of an inch or less, in most cases when one lane is laid, it must be provided with a ramp.




Ramps, unfortunately, create a number of other problems. One problem is at the beginning or ending of a mat, the wedge section must be adjusted manually during the transition, thus increasing the potential for an unacceptable section of pavement. Another problem with ramps is that they make it more difficult to create solid joints.




To address the joint creation and drop off problems, the concept of the “tapered joint” ramp was developed. At least two versions of tapered joints are in use: First, as shown in

FIG. 1A

, the “Jersey Unit,” as developed in the state of New Jersey during the 1980's, includes a first pavement mat


6


including a ramp


1


having a tapered portion


2


extending from a surface


3


of an adjacent and/or underlying material


4


directly up to a horizontal surface


5


of a new pavement mat


6


. Second, as shown in

FIG. 1B

, the “Stepped Tapered Joint,” as currently used in the state of Michigan, includes a first pavement mat


16


including a ramp


11


having a tapered portion


12


extending from a step


12


B to a second step


12


A on a surface


13


of an adjacent and/or underlying material


14


. The stepped tapered joint is basically a stepped jersey unit.




While tapered joint ramps cure the drop off problem, it unfortunately remains extremely difficult to form a solid long-lasting joint for the reasons that follow.




In terms of the jersey unit, a number of problems arise:




First, traffic which crosses over tapered portion


2


of ramp


1


partially compacts a line


7


between horizontal portion


5


of pavement mat


6


and tapered portion


2


of ramp


1


. This compaction makes it very difficult or impossible to discern the actual edge of mat


6


during laying of a second pavement mat


8


, shown in phantom in FIG.


1


A. As a result, either ramp


1


must be removed or very precise paving machine operation is required to follow an almost non-existent edge


7


of first pavement mat


6


. When second pavement mat


8


is laid over ramp


1


, frequently the result is a feathered joint


9


where second pavement mat


8


lays over ramp


1


but does not have its edge meet cleanly with edge


7


of first pavement mat


6


, i.e., either second pavement mat


8


is short of edge


7


or passes over edge


7


. Feathered joint


9


is problematic because it may include a visible rut between pavement mats that can lead to deterioration and ravel under traffic. Additionally, water may gain easy access through feathered joint


9


and under second pavement mat


8


which may cause roadway heaving or separation problems.




Second, full compaction is oftentimes only applied to the horizontal part of first pavement mat


6


. Tapered portion


2


of ramp


1


is normally only exposed to that compaction provided by the screed that forms it and whatever traffic crosses it. See e.g., U.S. Pat. No. 4,181,449 to Lenker, and U.S. Pat. No. 4,818,140 to Carlson. As a result, tapered portion


2


includes a low density area


10


which by the time second pavement mat


8


is laid has cooled and is extremely resistant to further compaction. Second pavement mat


8


does not contain a sufficient amount of hot material over low density area


10


to allow further compaction. The resulting joint therefore is immediately suspect.




Third, because the outermost extent of tapered portion


2


must be created by pavement material at its core particle size, e.g., small stones, it is oftentimes impossible to construct the outermost extent of tapered portion


2


such that it irremovably compacts into the rest of tapered portion


2


and/or adjacent/underlayer material


4


. As a result, a loose aggregate safety problem persists.




Referring to

FIG. 1B

, the stepped tapered joint ramp was developed to alleviate the problems of raveling and edge following. By providing a step


12


B at an edge


17


of new pavement mat


16


, a feathered edge is prevented. Further, step


12


B provides a defined line or edge


17


which alleviates the problem of having to follow an undecipherable compacted edge of first pavement mat


16


. Unfortunately, the compaction problem for the tapered or wedge section


12


remains, i.e., a low density area


20


that is resistant to compaction exists. Further, if the proper height for step


12


B is not incorporated, e.g., because different asphalt formulations have different compaction ratios, step


12


B can be rolled out of existence when the rest of first pavement mat


16


is compacted.




One remedy for the joint creation problems of ramps has been to remove the ramps prior to laying the second pavement mat. Unfortunately, this process is very time consuming and difficult because the material has cooled and hardened. It may also necessitate additional lane closure to accommodate equipment.




In view of the foregoing, there is a need for a paving machine and pavement edger therefor which allow for accommodation of drop off from a new pavement mat and the creation of solid pavement joints.




SUMMARY OF THE INVENTION




In a first general aspect of the invention is provided a pavement edge maker comprising: a first compaction surface and a second compaction surface, the first compaction surface being offset vertically from the second compaction surface by a substantially vertical third compaction surface.




In a second general aspect of the invention is provided a paving machine comprising: means for laying a pavement mat having an edge; and means, coupled to the means for laying an asphalt mat, for forming a highly compacted step on the edge of the mat and a tapered portion extending away from a vertical face of the step, the tapered portion including a highly compacted area.




In a third general aspect of the invention is provided a pavement edger adapted for connection to a screed for creating an edge on an end of a mat of pavement, the edger comprising: a step making surface for making a compacted step; a ramp making surface for making a compacted tapered ramp adjacent to the compacted step; and a retraction mechanism to retract the step making surface and ramp making surface flush with the screed.




Using the above paving machine and pavement edger solves many of the above described problems of the prior art. First, the ramp provided in accordance with the present invention eliminates the drop off at an edge of a new pavement mat. Hence, time constraints, traffic, equipment shortages, etc., are no longer problematic. The safety problems associated with drop offs are also resolved and all federal and state highway contracting regulations can now be met with ease. The problems associated with the beginning or ending of a mat are resolved as the edger in accordance with the invention may be connected to the screed in such a way as to be self-enabling. Because the ramp includes highly compacted areas, the joint creating problems such as: rounded edges from traffic creating feathered joints; lack of full compaction because of hardened and compaction resistant tapered portions, are resolved. Furthermore, there is no longer a need to remove ramps.




The foregoing and other features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention.











BRIEF DESCRIPTION OF THE DRAWINGS




The preferred embodiments of this invention will be described in detail, with reference to the following figures, wherein like designations denote like elements, and wherein:





FIGS. 1A-1B

are side views of prior art pavement mat edges;





FIG. 2

is a perspective view of a paving machine equipped with an edger in accordance with the present invention;





FIG. 3

is a front perspective view of the edger;





FIG. 4

is a front elevational view of a first embodiment of the edger mounted to the paving machine;





FIG. 5

is a front elevational view of a second embodiment of the edger mounted to the paving machine;





FIG. 6

is a front elevational view of the edger in a retracted position;





FIG. 7

is a rear perspective view of the edger in operation;





FIG. 8

is a side elevational view of the edger in operation as viewed from within the screed;





FIG. 9

is a front elevational view of a flexible seal strike off for the edger in accordance with an embodiment of the invention; and





FIG. 10

is a top view of the strike off on the edger;





FIG. 11

is a cross-sectional view of a pavement ramp created with the edger in accordance with the invention; and





FIG. 12

is a cross-sectional view of a joint in accordance with the present invention.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




Although certain preferred embodiments of the present invention will be shown and described in detail, it should be understood that various changes and modifications may be made without departing from the scope of the appended claims. The scope of the present invention will in no way be limited to the number of constituting components, the materials thereof, the shapes thereof, the relative arrangement thereof, etc., and are disclosed simply as an example of the preferred embodiment.




For definition herein, a “mat” or “pavement mat” is considered a layer of paving material. A “step” is considered an offset area where a substantially vertical surface meets another surface. “Paving material” is any material used for paving roadways, such as bituminous material like asphalt.




For initial reference, attention is directed to

FIG. 11

which illustrates a ramp


100


created in accordance with the present invention. Ramp


100


includes a step


111


on an edge


110


of pavement mat


102


and a tapered portion


108


extending away from a vertical face


112


of step


111


. Step


111


and at least a section, e.g., upper end


114


, of tapered portion


108


are compacted between 85% and 93% of complete compaction of the paving material to create highly compacted areas


118


,


120


. By “highly compacted” is meant that paving material is compacted between 85% to 93% of its complete compaction, a percentage higher than if paving material was simply leveled by a screed


40


. Screeding normally only provides a compaction rate of 80% or less. A second step


116


is also provided at a lower end


115


of tapered portion


108


. Tapered portion


108


may also include a flattened portion


117


at lower end


115


. Ramp


100


will be discussed in more detail below.




Referring to

FIG. 2

, a paving machine


30


equipped with an edger or pavement edge maker


50


of the present invention is illustrated operating to spread and grade paving material


32


, e.g., a paving road mix such as asphalt, etc., on an adjacent surface


34


to form pavement mat


102


with a ramp


100


on its edge or shoulder. The paving machine


30


has a rear main screed


40


extending from an upright moldboard


42


. Elevation of screed


40


is determined by adjustment of a pair of tow arms


44


pivotally connected to a supporting frame


46


for moldboard


42


and screed


40


. Asphalt mix carried by paving machine


30


is spread laterally in front of moldboard


42


by augers (not shown) which are spaced forwardly of moldboard


42


. Paving machine


30


may also include an optional screed extender


48


(

FIGS. 4-7

) to extend screed


40


and/or a vertically adjustable end gate


49


(FIGS.


3


-


7


), as are commonly known in the art. End gate


49


may include a vertically adjustable sled


47


, as is conventional.




Referring to

FIGS. 3-8

, edger


50


is illustrated in more detail. Edger


50


includes a first compaction surface


52


, a second compaction surface


53


and a third substantially vertical compaction surface


54


. Compaction surfaces


52


,


53


,


54


are preferably constructed of metal plating, e.g., steel plating. Compaction surfaces


52


,


53


,


54


have a special alignment to create ramp


100


in accordance with the present invention. In particular, compaction surfaces


52


,


53


are angled upwardly at an angle α relative to a forward direction of travel A of paving machine


30


to receive and compact paving material


32


thereunder.




Similarly, third compaction surface


54


is also angled upwardly at angle α along a lower edge


59


thereof. The angle α is less than 45° so as to allow receipt and compaction of paving material


32


without plowing thereof. First compaction surface


52


is fixed relative to edger mounting plate


88


and may include support structure


55


between a back surface thereof and an edger mounting plate


88


. Compaction surfaces


53


,


54


are vertically adjustable relative to first compaction surface


52


as will be further described below.




Third compaction surface


54


is substantially vertical, as best seen in

FIGS. 4-5

, and is also angled in a horizontal lateral direction B at an angle β, as best seen in FIG.


3


. Horizontal lateral angle β allows compaction surface


54


to receive and compact paving material


32


horizontally to form substantially vertical face


112


. To accommodate angle β and to prevent material from passing between first and third compaction surfaces


52


,


54


, first compaction surface


52


includes mating angled edge


61


created by having a rearward lower edge


58


shorter than a forward upper edge


60


. Similarly, second compaction surface


53


may also include a rearward lower edge


62


that is longer than a forward upper edge


64


to accommodate angle β and to assure that outermost edge


70


of second compaction surface closes against end gate


49


when retracted, as will be discussed below. First compaction surface


52


may also include a curved edge


56


to accommodate paving material


32


adjacent thereto.




As best shown in

FIGS. 4-5

, rearward lower edge


62


of second compaction surface


53


is angled at an angle Δ relative to horizontal lateral direction B to create tapered portion


108


, as will be described below. Second compaction surface


53


is preferably pivotally mounted to third compaction surface


54


by a hinge


66


to allow for adjustment of angle Δ. Adjustment of angle Δ has two effects: first, it alters angle Δ of tapered portion


108


, and second, either alone or in combination with vertical adjustment, it varies the height of second step


116


on lower end


115


of tapered portion


108


. Second step


116


is created between second compaction surface


53


and end gate


49


, which acts as a fourth compaction surface.




Angular adjustment of second compaction surface


53


relative to either moldboard


42


or optional end gate


49


, along with vertical movement of optional end gate


49


, may create a gap between second compaction surface


53


and the above structures. To prevent passage of paving material


32


therethrough, a flexible seal strike off


68


is provided on outer edge


70


of second compaction surface


53


. As shown in

FIGS. 9 and 10

, flexible seal strike off


68


is preferably a flexible sheet of spring steel


72


having a beveled corner


74


and a connection flap


76


. Strike off


68


is attached, e.g., by welding, bolting, etc., by connection flap


76


to second compaction surface


53


and extends generally upwardly therefrom. As angle Δ of third compaction surface


53


and/or vertical movement of end gate


49


varies, strike off


68


flexes to accommodate the gap and maintain a strike off surface, as best shown in

FIGS. 4-5

and


10


. If end gate


49


is ever raised above second compaction surface


53


, beveled corner


74


allows for re-mating and gradual flexing of strike off


68


against end gate


49


.




Referring to

FIGS. 4-5

, edger


50


also preferably includes an adjustment system


80


. Adjustment system


80


can adjust the depth of third compaction surface


54


and second compaction surface


53


, relative to first compaction surface


52


; adjusts angle Δ of second compaction surface


53


; and can also operate as a retraction mechanism for second and third compaction surfaces,


53


,


54


as will be described below. Adjustment is preferable to accommodate varying system characteristics, e.g., different paving material


32


having different compaction ratios, change in atmospheric temperature, different screeds, screed extenders or end gates, etc. Preferably, adjustment system


80


is adjustable to allow for pavement mats with a thickness ranging from approximately 1 inch to 5 inches uncompacted, i.e., ¾ inches to 4 or more inches compacted. It should be recognized, however, that if characteristics are known to be constant or fairly constant, that a fixed device is considered within the scope of the invention. In this circumstance, compaction surfaces


52


,


53


,


54


would be fixed in position. Strike off


68


, if necessary, would also be fixed, e.g., a welded plate.




Retraction is preferable because it allows edger


50


to operate as an edger and as a screed joint maker for creation of joint


101


of FIG.


12


. Hence, edger


50


can crate ramp


100


and also joint


101


without having to remove any parts from paving machine


30


or edger


50


.




In order to vertically adjust second and third compaction surfaces


53


,


54


, in a first preferred embodiment shown in

FIG. 4

, adjustment system


80


includes a threaded vertical adjustment crank


82


which is fixedly attached at a lower end


84


thereof to third compaction surface


54


. Vertical adjustment crank


82


threads into a threaded mount


86


fixedly coupled to edger mounting plate


88


. Third compaction surface


54


is pivotally coupled to a pivot plate


81


which is fixed to first compaction surface


52


. A pivot pin


83


extends through pivot plate


81


into third compaction surface


54


. By turning vertical adjustment crank


82


, second and third compaction surfaces


53


,


54


are vertically adjusted as crank


82


is held by threaded mount


86


. Third compaction surface


54


may include a rounded rear edge to accommodate pivoting motion, if necessary.




As shown in

FIG. 6

, second and third compaction surfaces


53


,


54


can also be retracted such that their lowermost edges are even or flush with rearward edge


58


of first compaction surface


52


and/or screed


40


an/or screed extender


48


. The edges that second and third compaction surface


53


,


54


will be flush with will depend on the vertical positioning of edger


50


by a vertical positioning system


150


, discussed below, and the degree of retractability of surfaces


52


,


54


. In its fully retracted position, outermost edge


70


of second compaction surface


53


is substantially flush with an inner surface of end gate


49


such that flexible seal strike off


68


is not in use. In this retracted position, edger


50


need not be removed during the laying of a second pavement mat


130


, as shown in

FIG. 12

, and can operate as a joint maker.




Referring to

FIG. 5

, an alternative embodiment for vertical adjustment is shown. In this embodiment, rear edges of second and third compaction surfaces


53


,


54


may be held to edger mounting plate


88


by channels (not shown) or other structure to allow for translational vertical movement. Otherwise, vertical adjustment works in the same way as with the first embodiment.




Adjustment system


80


also includes angular adjustment crank


90


to vary angle Δ of second compaction surface


53


. As noted above, second compaction surface


53


is pivotally attached to lower edge


59


of third compaction surface


54


by a hinge


66


. At a lower end


92


, angular adjustment crank


90


is fixedly and pivotally attached to second compaction surface


53


on an upper side thereof. Angular adjustment crank


90


also is coupled to vertical adjustment crank


82


by element


94


. Element


94


is fixedly attached at one end


95


to vertical adjustment crank


82


and holds threaded mount


96


for angular adjustment crank


90


at a second end


97


. As vertical crank


82


is moved, angular adjustment crank


90


and, hence, second compaction surface


53


, moves with vertical crank


82


because of element


94


. To adjust angle Δ, crank


90


is turned to either increase or decrease the distance between second compaction surface


53


and threaded mount


96


. As noted above, adjustment of angle Δ has two effects: it alters the angle of tapered portion


108


, and it varies the height of second step


116


on lower end


115


of tapered portion


108


. Hence, either vertical or angular adjustment can vary the height of step


116


.




It should be recognized that while a particular adjustment system


80


has been illustrated, that a variety of different mechanisms are possible. Accordingly, the scope of this invention should not be limited to any particular adjustment mechanism. It should also be recognized that any other structural elements that may be necessary to retain compaction surfaces


52


,


53


,


54


in proper positioning may also be provided. For instance, channel members (not shown) may be provided on edger mounting plate


88


to mate with parts of compaction surfaces


52


,


53


,


54


, e.g., channel slide members, to direct movement and retain the surfaces relative to edger mounting plate


88


.




Edger


50


can be mounted to a front side of screed


40


or screed extender


48


by edger mounting plate


88


and an adjustable system of bolts


76


and slots


78


, as shown in

FIGS. 3-5

. It should be recognized, however, that any system which allows for quick connection of edger


50


to screed


40


or screed extender


48


may be utilized. A quick connection is preferable because edger


50


may have to be removed for transport, especially when mounted in screed extender


48


.




In a preferred embodiment, edger


50


is mounted to screed


40


or screed extender


48


by an edger positioning system


150


, as shown in

FIGS. 3 and 8

. Edger positioning system


150


can be any device


152


that allows vertical adjustment of edger


50


relative to screed/extender


40


,


48


. Vertical adjustment is required for start up and ending a pavement mat, or paving on or off bridges. In a preferred embodiment, edger positioning system


150


is constituted by a hydraulic ram system


156


, as shown in FIG.


8


. Other possibilities, for edger positioning system


150


are spring biased systems, or motorized systems, etc. Edger positioning system


150


can be mounted to screed


40


or screed extender


48


by a bolt and slot systems


154


, or the above mentioned quick connect systems (not shown).




In pavement mat starting operation, end gate


49


, screed


40


and screed extender


48


, if provided, would be in contact with adjacent surface


34


. If edger positioning system


150


is an automatic type device, e.g., a hydraulic ram system


156


, it is preferable to have edger


50


positioned out of contact with adjacent surface


34


, i.e., with second compaction surface


53


out of contact. Alternatively, if edger positioning system


150


is a spring-biased system, edger


50


may be in ground contact and biased upwardly. As paving machine


30


proceeds to begin paving operations, screed


40


and screed extender


48


, if provided, are raised. Simultaneously, end gate


49


lowers, either controllably or by its own accord as is common in the art, to maintain ground contact. At this time, edger positioning system


150


operates to correctly position edger


50


relative to screed


40


. For instance, if edger positioning system


150


is a spring-biased system, edger


50


being raised with screed


40


out of ground contact would allow the springs (not shown) to bias edger


50


downwardly to a correct position, possibly set by an adjustable stop. If edger positioning system


150


is a hydraulic ram system


156


, then hydraulic ram system


156


can be activated to position edger


50


correctly. In pavement mat ending operation, edger positioning system


150


would operate in reverse order as discussed above, i.e., raising edger


50


out of ground contact as screed


40


and screed extender


48


, if provided, are lowered.




Edger


50


may also include a side


98


and cover


99


to enclose the side, top and front of edger


50


. Cover


99


may include a handle


140


, as shown in

FIG. 8

, for ease of transport of edger


50


.




Referring to

FIGS. 7

,


11


and


12


, operation of edger


50


to create ramp


100


, illustrated in

FIG. 11

, will be described. Edger


50


is mounted either inside screed


40


or screed extension


48


. Vertically movable end gate


49


may be added, if desired. As paving machine


30


proceeds, paving material


32


is heated and laid out in front of screed


40


which levels most of paving material


32


into a pavement mat


102


. At an edge


110


of pavement mat


102


, edger


50


works to create ramp


100


in accordance with the present invention. In particular, first compaction surface


52


vertically compacts a top surface of edge


110


of pavement mat


102


. Simultaneously, substantially vertical third compaction surface


54


horizontally compacts substantially vertical face


112


of edge


110


. In combination, first and third compaction surfaces


52


,


54


provide a highly compacted step


111


having a highly compacted portion


118


. Again, “highly compacted” means that paving material


32


is compacted between 85% to 93% of its complete compaction, a percentage higher than if material


32


was simply leveled by screed


40


.




As will be observed in

FIGS. 4-5

and


8


, it is preferable to mount edger


50


such that rearward lower edge


58


of first compaction surface


52


is a distance D above the bottom of screed


40


or screed extender


48


. In this way, a pre-compaction zone


160


is created beneath edger


50


and a primary compaction zone


162


is created beneath screed


40


or screed extender


48


. It should be recognized, however, that rearward lower edge


58


of first compaction surface


52


need not be above the bottom of screed


40


or screed extender


48


to attain the advantages of the present invention.




At the same time that step


111


is being formed, second compaction surface


53


is also forming and compacting tapered portion


108


having an upper end


114


and a lower end


115


. Second compaction surface


53


is positioned vertically and angled so as to highly compact tapered portion


108


and form a highly compacted area


120


therein. Preferably, tapered portion


108


also includes a second step


116


at lower end


115


thereof. Second step


116


is formed against moldboard


42


or end gate


49


which acts as a fourth compaction surface. Second step


116


prevents loose aggregate from being left behind as in prior art devices. It will also be noticed that if a gap is present between second compaction surface


53


and end gate


49


, strike off


68


will create a flattened portion


117


at lower end


115


of tapered portion


108


.




In view of the foregoing, the process of producing ramp


100


includes: forming highly compacted step


111


on edge


110


of first pavement mat


102


by horizontally compacting substantially vertical face


112


and by vertically compacting a top surface of first pavement mat


102


; and forming a tapered portion


108


extending away from substantially vertical face


112


of step


111


with tapered portion


108


including a at least a section or area


120


that is highly compacted. Highly compacted areas


118


,


120


are compacted between 85% and 93% of complete compaction. As an option, another step


116


may be formed at a distal end


115


of tapered portion


108


from substantially vertical face


112


. Further, pavement mat


102


may be rolled to a more complete compaction, e.g., up to approximately 98% of complete compaction as a finishing step.




Referring to

FIG. 12

, a joint


101


, created with paving machine


30


and edger


50


, in accordance with the present invention is illustrated.




Joint


101


can be created using the above processes for creating ramp


100


of

FIG. 11

, followed by: laying a second pavement mat


130


adjacent first pavement mat


102


such that an edge


132


of second pavement mat


130


abuts substantially vertical face


112


of edge


110


, and then compacting second pavement mat


130


. The final compaction would be up to approximately 98% of complete compaction. Preferably, laying of second pavement mat


130


would include using edger


50


with second and third compaction surfaces


53


,


54


retracted so as to form a contiguous joint maker surface. In this instance, edger


50


may be vertically adjusted to have its rearward lower edges


58


,


62


even or flush with screed


40


or screed extender


48


so as to provide even compaction across the entire second pavement mat


130


, and whatever part of first pavement mat


102


is covered. As an alternative, edger


50


could be removed and pavement mat


130


laid in a conventional manner.




As an alternative, processes are provided in accordance with the invention to create joint


101


from nothing as follows: First, lay first pavement mat


102


having edge


110


. Pavement mat


102


can be leveled by a conventional screed


40


. Next, form highly compacted step


111


on edge


110


of first pavement mat


102


and a highly compacted tapered portion


108


extending away from vertical face


112


of step


111


. Highly compacted areas


118


and


120


are compacted between 85% to 93% of complete compaction. Pavement mat


102


may be rolled to a more complete compaction, e.g., up to approximately 98% of complete compaction. Last, a second pavement mat


130


is laid adjacent first pavement mat


102


such that an edge


132


of second pavement mat


120


abuts vertical face


112


. Laying second pavement mat


130


includes leveling with a conventional screed.




It is to be recognized, that the presence of highly compacted areas


118


,


120


provide an advantage to creation of joint


101


. For instance, one will recognize that when second pavement mat


130


is laid, less material


134


is necessary over tapered portion


108


. In normal non-highly compacted ramps/joints, as shown in

FIGS. 1A and 1B

, an upper section of tapered portion


2


,


12


would include a low density area


10


,


20


. Low density area


10


,


20


, because of its thickness and the thinner amount of paving material in the second pavement mat atop of it, would not be sufficiently heated to accommodate further compaction. In contrast, in accordance with the present invention, upper end


114


of tapered portion


108


is already highly compacted and therefore does not need as much further compaction. Further, the thinner layer of material overlying upper end


114


provides sufficient heat to allow for finishing compaction of upper end


114


and the seam between vertical face


112


and edge


132


of second pavement mat


130


.




Second pavement mat


130


is compacted in a conventional way from a level shown in phantom in

FIG. 12

to form joint


101


. Compaction at this point is up to approximately 98% of complete compaction. Adjacent to second step


116


, second pavement mat


130


has the same thickness as first pavement mat


102


.




The invention also includes joint


101


created by the above processes and including: a first asphalt section


102


mating with a second asphalt section


130


to form a substantially seamless joint with second asphalt section


130


. Second asphalt section


130


including a first step


111


and a ramp portion


108


extending away from a lower portion of first step


111


. First step


111


and a section


120


of ramp portion


108


are highly compacted prior to first asphalt section


102


mating with second asphalt section


130


.




While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.




For instance, it should be recognized that edger


50


may either provide pre-compaction or post-compaction of pavement depending on its position relative to the screed. In other words, although edger


50


has been illustrated as being mounted in front of screed


40


or screed extender


48


, it is also within the scope of the invention that edger


50


follow screed


40


or screed extender


48


to provide post-compaction. In this instance, the forming steps for ramp


100


are preceded by the leveling of first pavement mat


102


by screed


40


.



Claims
  • 1. A pavement edge maker comprising:a first compaction surface and a second compaction surface, the first compaction surface being offset vertically from the second compaction surface by a substantially vertical third compaction surface and; wherein the third compaction surface is set at an angle in a horizontal lateral direction relative to a forward direction of movement of the pavement edge maker to receive and compact material in a horizontal direction.
  • 2. The pavement edge maker of claim 1, wherein each of the compaction surfaces is set at an upward angle relative to the forward direction of travel of the pavement edge maker.
  • 3. The pavement edge maker of claim 2, wherein the upward angle is less than 45 °.
  • 4. The pavement edge maker of claim 1, further comprising a coupling device to couple the pavement edge maker to one of a paving machine screed and a screed extension thereof.
  • 5. The pavement edge maker of claim 2, wherein the second compaction surface is angled relative to the third compaction surface.
  • 6. The pavement edge maker of claim 5, wherein the second and third compaction surfaces are pivotally connected to each other.
  • 7. The pavement edge maker of claim 6, further comprising an angle adjustment mechanism for the second compaction surface relative to a third compaction surface.
  • 8. The pavement edge maker of claim 5, further comprising a height adjustment mechanism for the second and third compaction surfaces relative to the first compaction surface.
  • 9. The pavement edge maker of claim 1, further comprising a mechanism to adjust the height of the pavement edge maker.
  • 10. The pavement edge maker of claim 1, further comprising a self-adjusting mechanism to bias the pavement edge maker downwardly.
  • 11. The pavement edge maker of claim 1, further comprising a vertical fourth compaction surface positioned at an end of the second compaction surface distal from the first compaction surface.
  • 12. The pavement edge maker of claim 11, further comprising a flexible seal strike off between the fourth compaction surface and the second compaction surface to accommodate pivoting of the second compaction surface.
Parent Case Info

This application is a continuation-in-part of Provisional Application No. 60/125,602, filed Mar. 19, 1999.

US Referenced Citations (14)
Number Name Date Kind
2311286 Tufts Feb 1943
3108518 O'Connor, Jr. Oct 1963
3398663 Matich Aug 1968
3625121 Blumer Dec 1971
4027990 Merrill Jun 1977
4068969 Beach et al. Jan 1978
4181449 Lenker Jan 1980
4818140 Carlson Apr 1989
5051026 Sovik Sep 1991
5088854 Sovik Feb 1992
5213442 Sovik May 1993
5336019 Hollon et al. Aug 1994
5344254 Sartain Sep 1994
5362176 Sovik Nov 1994
Foreign Referenced Citations (3)
Number Date Country
990565 Jun 1976 CA
2 113 358 Sep 1972 DE
0 027 164 Apr 1981 EP
Non-Patent Literature Citations (1)
Entry
Public Works, “Hazards of Pavement Edge Dropoff,” Public Works Journal Corporation, vol. 125, No. 13 p. 38, Dec. 1994.
Provisional Applications (1)
Number Date Country
60/125602 Mar 1999 US