U.S. patent number 3,905,714 [Application Number 05/488,427] was granted by the patent office on 1975-09-16 for method for restoring concrete road surfaces.
Invention is credited to Glen E. Perkins.
United States Patent |
3,905,714 |
Perkins |
September 16, 1975 |
Method for restoring concrete road surfaces
Abstract
Process and apparatus for restoring the driving surface of
concrete highways comprising, in the first instance, use of a
compactor equipped with sharp pointed teeth adapted upon rolling
the compactor over the highway to puncture, fragment and
disintegrate the surface layer of the concrete to a controlled
thickness, thereby to remove the smooth or slick surface layer and
restore the driving surface to a skid resistant textured character.
Where highway wear has been excessive and/or following one or more
of the restorative procedures above described, the process and
apparatus comprise, in the second instance, use of slip form paving
means and special paving techniques to resurface the highway with
concrete, and in particular to continuously resurface in one pass
one traffic lane and the contiguous shoulder without fixed forms or
special shoring-up of the shoulder and without closing the other
lane of the highway to regular traffic.
Inventors: |
Perkins; Glen E. (East Moline,
IL) |
Family
ID: |
26953786 |
Appl.
No.: |
05/488,427 |
Filed: |
July 15, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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269591 |
Jul 7, 1972 |
3844670 |
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Current U.S.
Class: |
404/72 |
Current CPC
Class: |
E01C
19/486 (20130101); E01C 23/088 (20130101) |
Current International
Class: |
E01C
23/088 (20060101); E01C 19/48 (20060101); E01C
19/00 (20060101); E01C 23/00 (20060101); E01C
003/06 () |
Field of
Search: |
;404/104,72,75,90,121,83 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Byers, Jr.; Nile C.
Attorney, Agent or Firm: Gary, Juettner, Pigott &
Cullinan
Parent Case Text
This is a division of application Ser. No. 269,591 filed July 7,
1972, now U.S. Pat. No. 3,844,670.
Claims
Having thus described the invention, what is claimed is:
1. A process for restoring the surface of a concrete highway
comprising the steps of disposing the slip form paving tools in
overlying relation to one traffic lane and the contiguous shoulder
of the highway, supporting said tools from a generally rectangular
frame, supporting said frame essentially adjacent three corners
thereof, namely, the front and rear corners contiguous to the other
traffic lane and the front corner contiguous to the shoulder,
driving said frame and tools by traction means located adjacent
said three corners and adapted to ride respectively on the edge of
the other traffic lane and on said shoulder forwardly of said
tools, and simultaneously and continuously slip forming a fresh
layer onto said one lane and the contiguous shoulder.
2. A process as set forth in claim 1, including the step of
depositing concrete on said one traffic lane to be received between
the two front traction means, spreading the concrete laterally to
the edge of the shoulder behind the traction means riding on the
shoulder, and then slip forming the concrete onto the one traffic
lane and contiguous shoulder.
3. A process as set forth in claim 1, including the preliminary
step of preparing the surface of the original highway to attain a
good bond between it and the resurfacing layer by subjecting said
surface to controlled impact from tools of limited surface area for
puncturing and fragmenting the surface to a controlled depth.
4. Method for concrete resurfacing of a concrete highway having at
least two lanes and respective contiguous shoulders comprising the
steps of suspending a slip form paving apparatus over one lane and
shoulder from mobile ground supports engaging another lane said one
shoulder ahead of said apparatus, and continuously applying a
concrete surface to said one lane and shoulder while moving said
apparatus forwardly on said supports.
5. The method according to claim 4 comprising the further steps of
allowing the new concrete to set, turning said apparatus around,
and repeating the paving operation on the shoulder of the other
lane and shoulder.
6. A process for restoring the surface of an existing concrete
highway having two finished lanes of travel and a finished shoulder
contiguous with each of said lanes comprising the steps of
subjecting the surfaces of said lanes and shoulders to controlled
impact from tools of limited surface area for puncturing and
fragmenting the surface layer to a controlled depth, clearing away
the fragmented surface layer, disposing slip form paving tools in
overlying relation to the entire width of one of said lanes and the
contiguous one of said shoulders, supporting said tools from a
generally rectangular frame, supporting said frame essentially
adjacent three corners thereof, namely, the front and rear corners
contiguous to the other of said lanes and the front corner
contiguous to said one shoulder, driving said frame and tools by
traction means located adjacent said three corners and riding
respectively on the edge of said other lane and on said one
shoulder forwardly of said tools, and simultaneously and
continuously slip forming a fresh layer of concrete over the entire
width of said one lane and said one shoulder.
Description
BACKGROUND OF THE INVENTION
In constructing concrete highways, the surface of the concrete is
textured or grooved so as to impart skid resistance to the surface.
Subsequently, as traffic moves over the highway, the surface is
worn away and becomes smooth or slick, whereupon skid-resistance is
lost. After excessive wear, it becomes necessary to resurface the
highway.
Existing concrete highways, such as in the interstate system,
comprise two or more concrete traffic lanes with adjacent paved
shoulders, the outer edges of the shoulders being contiguous with
sharply sloping and uneven earth, gravel or the like. When the
traffic lanes are resurfaced it is also necessary to resurface the
shoulders of the highway, which is usually done as a separate
operation. Also, one lane traffic should be kept open to allow
travel on the highway during the resurfacing operation.
Heretofore, the resurfacing of a highway with concrete has not been
feasible for a number of reasons, including the cumbersomeness of
concrete paving apparatus, the necessity for locating forms
(whether slip forms or stationary forms) outside the area to be
paved, and the curing time required before construction machinery
and/or traffic can operate on the newly paved surface.
The present invention comtemplates simultaneous resurfacing of one
traffic lane and the contiguous shoulder, which affords certain
advantages as will appear later herein, but which presents further
difficulties because of the irregularities and sharp slope of the
earth beyond the edge of the shoulder. There is no location
adjacent the edge of the shoulder that is suitable for engagement
by forms, and the ground surface beyond the shoulder edge is too
uneven and rough to provide level and adequate support for the
outside side tracks of a slip-form paver. Obstructions, such as
sign posts and barriers, are often located in the ground closely
adjacent the shoulder and would have to be removed. For these
reasons, concrete highways have not been resurfaced with concrete;
instead, asphalt or blacktop materials have been used
exclusively.
SUMMARY OF THE INVENTION
The present invention overcomes the problems stated above and
provides for resurfacing of highways with concrete by adapting
slip-form paving apparatus to the built-in limitations of existing
concrete highway construction.
According to the invention, one traffic lane and the contiguous
shoulder of the highway are continuously and simultaneously
resurfaced by slip-form paving apparatus that rides on the existing
highway surface, that does not require closing of the other lane of
traffic, and that does not rely or bear upon the ground outwardly
of the shoulder.
To accommodate the latter feature, the invention further provides a
slip form paver supported solely at the traffic lane side and the
front thereof and yet capable of precision slip form paving.
Specifically, the invention provides what might be called a
three-legged slip form paver, comprising a rigid rectangular frame
for mounting the slip form paving tools, such as those shown in
U.S. Pat. No. 3,247,770, a pair of longitudinally spaced tractive
supporting elements adjacent the two corners of the frame at the
traffic lane side thereof, and a third tractive supporting element
forwardly of the slip forming tools inwardly of but adjacent the
shoulder side of the machine, whereby the machine rides on the
traffic lane that is not being resurfaced and on the shoulder
forwardly of the paving tools; the frame providing cantilever
support from said three corners for the remaining corner of the
frame. In this manner, the machine is not dependent upon irregular
ground for support, and the span of the entire apparatus does not
block or hinder the flow of traffic over the other lane and
opposite shoulder of the road.
In addition, the invention provides for restoration of a textured
surface to a concrete highway that is otherwise not in need of
resurfacing, or one that is about to be resurfaced in order to
improve the bond between the original slab and the resurfacing
layer of concrete. Specifically, in accordance with the invention,
a compactor having means for controlling the speed and impact of
the working tool thereof is equipped with sharp, wear-resistant
teeth for puncturing, fragmenting and disintegrating the surface
layer of the original slab to a controlled thickness, whereby to
restore texture thereto.
THE DRAWINGS
FIG. 1 is a perspective view of a compactor equipped pursuant to
the invention for restoring texture to the surface of a concrete
highway. FIG. 2 is a plan view of a section of two lane highway
illustrating the arrangement of the highway lanes and the
shoulders.
FIG. 3 is a vertical sectional view of the highway shown in FIG.
2.
FIG. 4 is a plan view of a highway section similar to that of FIG.
2 showing thereon in plan view the skeleton framework and mobile
elements of the slip form paving or resurfacing apparatus of the
invention.
FIG. 5 is a plan view of said paving apparatus illustrating the
concrete working instrumentalities thereof, the frame of the
machine being omitted for the sake of clarity.
FIG. 6 is a front view of the apparatus shown in FIG. 5.
FIG. 7 is a fragmentary longitudinal section of the apparatus of
FIGS. 5 and 6.
DETAILED DESCRIPTION
FIGS. 1 and 2 illustrate a segment of a typical two lane highway of
the interstate type on which motor vehicles travel in the same
direction. The highway includes left and right hand traffic lanes
10 and 12 of equal width, usually twelve feet, and respective
contiguous inside and outside shoulders 14 and 16. As shown, the
outside or right hand shoulder may be about ten feet wide and is
normally wider than the left or inside shoulder, which may be about
6 feet wide. Both shoulders usually slope downward from the traffic
lanes, and the lanes may have a small degree of slope from the
center as shown in exaggerated fashion in the drawings. The highway
illustrated is initially constructed by conventional fixed form or
slip form methods, and the surface thereof is textured to impart
skid resistance and minimize hydroplaning.
During use of the highway, vehicular traffic will wear away the
textured surface whereupon the highway will become smooth, even
slick due to accumulation of oil, especially when it rains. It
would be desirable in these cases to restore the texture to the
highway surface thereby to restore the skid resistant
characteristic originally built into it.
According to this invention, compactors well known in the
construction industry may be utilized to achieve this result.
Referring to FIG. 1, I have shown a self-propelled compactor
comprised of a frame 70, a prime mover 72, traction wheels 74, a
compactor roll 76 and means (not shown) for vibrating or moving the
roll 76 up and down to cause the same to impart impact blows to the
material on which the roll 76 is riding. According to the
invention, the roll is provided with sharp, pointed, wear and
shock-resistant teeth 78 on the peripheral surface thereof. Then,
by driving the compactor over one lane of the highway in one or
more passes and adjusting the vibrating stroke of the roll 76, the
surface layer of concrete may be punctured to a controlled depth or
thickness, fragmented and the fragments pulverized so as to remove
the traffic-smoothed material and impart a fresh relatively coarse
texture to the surface. The highway is then swept, and reopened to
traffic with fully restored skid resistance. Preferably, the
compactor and sweeper are of a width to work on one traffic lane at
a time, so that the highway may be kept open to traffic on the
other lane thereof while the restoration process is taking
place.
After the above restoration process has been practiced a number of
times and/or the highway has become excessively worn, the highway
may be resurfaced with concrete by use of the apparatus of FIG.
4-7. Before resurfacing starts, the apparatus of FIG. 1 may again
be used as above described to texture the surface of the original
slab to insure a good bond therewith of the concrete resurfacing
layer.
Referring now to the FIGS. 4-7, FIG. 4 illustrates a basic
framework supported upon ground engaging elements for accomodating
concrete resurfacing of the highway by slip form paving techniques.
A conventional slip form paver requires ground support or mobile
traction elements at its four corners or along both its sides, and
slip forms are carried interiorly of the traction elements and
define opposite edges of the concrete strip being applied. The
present apparatus, by contrast, comprises a slip form paver that is
conventional supported only on one side by an elongate track or a
pair of longitudinally spaced track elements 18 and 20, which are
aligned longitudinally and adapted to ride near the edge 22 of the
lane 10 that is adjacent to the lane 12 being resurfaced. The other
side of the apparatus is supported upon a single traction element
24 located forwardly of the apparatus and inwardly of the lateral
span thereof, such that said element rides on the shoulder 16 to be
resurfaced.
The traction elements 18, 20 and 24 are tied together by a rigid
frame, generally indicated at 26 in FIG. 4, which in turn supports
the elements of the paving apparatus. The frame 26 may take the
form of an X, with the forward outside traction element 24 secured
by a first diagonal beam 28 to the rear inside element 20, and a
second or cantilever beam 30 secured at one end to the forward
element 18 and extending diagonally over the first beam and secured
thereto at the intersection of the beams at 32. The other end of
the second beam 30 terminates behind the outside tract on element
24 and is tied thereto by a third beam 34 between said element and
said end. The location of the three traction elements essentially
at three of the corners of the frame provides for ground support at
the front and side of the assembly, with the rigid frame 26
providing cantilever support for the free ends of the second and
third beams.
As illustrated, the resulting structure is in the form of a
rectangle having ground support means at three corners and being
devoid of ground support at the remaining corner. The beams 28 and
30 extend between diagonally opposite corners, with the beam 30
serving as a cantilever to support the outside rear portion of the
structure. If desired or required for purposes of rigidity,
additional beams may be employed in fabricating the frame. Only the
essence has been shown herein. In any event, irrespective of the
specific details of construction, the frame 26 and hence the paving
apparatus is suspended over the area being resurfaced from support
locations on the road beyond said area.
The traction elements 18, 20 and 24 may take any conventional form
but preferably are in the form of creeping endless tracks
comprising interconnecting links having outwardly facing flat pads
36 (FIG. 5) which engage the road individual motors to propel the
apparatus in the desired direction.
Also, each traction element may be pivotally mounted about a
vertical axis and connected to a steering mechanism (See U.S. Pat.
No. 3,423,859 for futher details.) Instead of the two
longitudinally adjacent traction elements 18 and 20 mentioned, a
single continuous element may be employed, as shown in U.S. Pat.
No. 2,869,931.
As best illustrated in FIGS. 5 and 6, the paving apparatus
indicated generally at 38, is carried by or suspending from the
frame 26, with the traffic lane side of the apparatus located
inwardly of the traction elements 18 and 20, and the shoulder side
extending beyond or outward of the traction element 24 and
laterally overlapping the third beam 34 of the frame. A pair of
slip forms 40 and 42 are mounted on the sides of the paving
apparatus so as to coincide with the edge of the traffic lane being
resurfaced and the outer edge of the contiguous shoulder. The
purpose of the slip forms is to support the wet cement during
extrusion thereof and until it has set sufficiently to be
self-supporting along its edges and to prevent the concrete from
slumping to one side during application, especially on a sloping
surface.
The concrete working elements of the paver of the present invention
may take any conventional form, but the preferred form is that
which is described in U.S. Pat. No. 3,247,770, incorporated herein
by reference. As shown in FIGS. 5, 6 and 7, the apparatus may
comprise a hopper or receiving area 44 located in the front of the
apparatus between the traction elements 18 and 24 to accommodate
easy access of a concrete truck, which may be backed up to the
apparatus on the existing slab of the traffic lane being resurfaced
without impending traffic in the other lane of the highway.
Spreading means, such for example as a belt spreader or an auger 46
is located behind the hopper area 44 and serves to roughly spread
the concrete between the slip forms 40 and 42 at a level
corresponding approximately to the desired level of finish. The
spreader 46 is followed by a plurality of submersible vibrators 48
which depend from the apparatus into the fresh concrete.
The vibrators may be followed by pressure operated tampers 50 and
then by an extrusion meter or plate 52, which extends across the
entire width of the new concrete surface between the slip forms 40
and 42. The extrusion meter 52 compacts and smooths the concrete
under pressure at the desired level from one edge of the new
concrete slab to the other, with the slip forms providing the
necessary interim support for the sides of the slab during
extrusion. In addition, the extrusion meter 52 may be followed by a
finishing belt or the like, which is indicated at 53 in FIG. 4, and
by a burlap or broom drag or other means (not shown) for imparting
texture to the new surface.
Although not essential, it is preferred that the concrete
manipulating elements, namely, the auger 46, vibrators 48, tampers
50 and extrusion meter 52 be suspended from a secondary framework
54 that is connected to the primary framework 26 by means of
vertically adjustable screws 56, which are positioned to allow for
necessary adjustments of the apparatus. Depending on requirements,
a bevel may be imparted to the exposed corner of the shoulder by
providing a hinge 58 in the outer slip form and providing a
hydraulic cylinder 60 or the like for pivoting the hinged portion
inwardly.
Inasmuch as the weight of the paving apparatus tends to overbalance
the unsupported corner of the primary frame, it is important that
the weight of some of the heavier components of the apparatus be
positioned in a manner to assure correct balance. As illustrated in
FIGS. 3 and 5, the apparatus is counterbalanced by locating heavier
components, such as motors, gear boxes and the like 62, at the
inside forward corner of the apparatus, preferably on or near the
inner end of the second beam 30.
In operation, the apparatus is brought to the area to be
resurfaced, such as to the right lane and shoulder shown in FIG. 4,
and the respective slip forms 40 and 42 are brought into register
with left edge of the right lane 12 and the edge of the shoulder
16. Concrete is then deposited in the hopper area 44 between the
front traction elements 18 and 24, and the auger 46 is operated to
carry the concrete laterally behind the element 24 and to roughly
level it between the side forms 40 and 42. Vibrators 48 and tampers
50 are activated while the apparatus is propelled forward on the
traction elements 18, 20 and 24, such that a uniform layer of new
concrete is applied over the worn concrete surface of both the lane
12 and the shoulder 16 in a one step operation. The thickness of
the new layer is of course determined by the extrusion meter
52.
An important feature of the invention is that the total span of the
entire apparatus is only slightly wider than the width of concrete
being applied. At the outside edge, the apparatus is substantially
flush with the edge of the shoulder, and does not extend outwardly
beyond the shoulder whereby it does not interfere with existing
signs, guard rails, etc. Although the inside edge of the apparatus
rides on the adjacent lane 10, the overlap on this lane is minimal
and does not hinder traffic, which may travel on the free left
shoulder 14 and the unused portion of the left lane 10. Since the
apparatus travels on existing road surfaces, the concrete
resurfacing layer may be precisely conformed to the slope and curve
of the original road.
After one lane and its adjacent shoulder have been resurfaced, and
the concrete has cured, the apparatus is turned around and the
operation repeated on the other traffic lane and shoulder. In this
case, the edge of the newly applied layer of concrete on the lane
12 take the place of the slip form 42, which for this reason is
preferably removed. Also, the tracks 18 and 20 ride on the surface
of the newly applied concrete in lane 12, and the supporting means
for said tracks are vertically adjustable to accommodate leveling
of the frame 26, and proper disposition of the concrete working
elements. In order to accommodate for the reduced width of the
shoulder 14, the concrete finishing elements and the frame of the
machine may be designed to accommodate width adjustments in manners
known in the art. In this manner, the lane 10 and shoulder 14 can
be simultaneously resurfaced contiguously to the new slab on lane
12 and shoulder 16.
From the foregoing, it will be appreciated that various changes to
the apparatus, and rearrangement and modification of its parts, may
be made without departing from the scope of the invention. Other
expedients, for example, may be provided for supporting one or more
sides of the paving apparatus on an existing paved surface and
suspending the apparatus over the surface to be repaved by means of
a counterbalance. Although the method and apparatus of the present
invention has been described particularly with concrete roads
having concrete shoulders, it is obvious that the apparatus is
equally suitable for the resurfacing of concrete roads which do not
have shoulders or which have a shoulder on one side only.
* * * * *