US 3625121 A
Description (OCR text may contain errors)
United States Patent  Inventors Mathias Blumer Hunibach;
Walter Gasser, Gwatt, both of Switzerland [2|] Appl. No. 865,280  Filed Oct. 10, 1969  Patented Dec. 7, 1971  Assignee Frutiger Sohne AG.
Thun, Switzerland  APPARATUS FOR PRODUCING SUPPORTING LAYERS 0R ROAD SURFACES 1 Claim, 4 Drawing Figs.  U.S. Cl 94/48 [5!] Int. Cl E0lc 19/30  Field of Search 94/39, 46, 48, 22 56] References Cited UNITED STATES PATENTS 3,363,523 1/1968 Brock 94/46 2,541,547 2/1951 Robinson 94/46 2,587,321 2/1952 Hohnke 94/45 2,589,256 3/1952 Homing 94/46 2,881,683 4/1959 Konway..... 94/45 3,137,220 6/l964 Smith 94/46 Primary E.raminerNile C. Byers,Jr. An0rney Werner W. Kleeman ABSTRACT: There is disclosed a method for producing bituminous layers having at least one marginal rim, curbing, shoulder, gutter or other profiled edge configuration, termed abutment, in which bituminous mix is laid out over the area of the road and the area of the abutment with the abutment being shaped to the desired profile and simultaneously precompacted. Another aspect of the method includes subjecting the shaped and precompacted abutment to a second precompacting step. The method includes applying additional heat to the mix of the abutment during either or both precompacting steps. There is also disclosed apparatus for carrying out the method including a means for laying out and precompacting an area of the bituminous layer, a laterally connected and relatively movable guide plate for shaping the desired profile, a profiled drag plate connected to the guide plate in trailing relation therewith and vibrating and heating means operably associated with either one or both of the guide and drag plate.
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BMW M ATTORNEY J APPARATUS FOR PRODUCING SUPPORTING LAYERS OR ROAD SURFACES BACKGROUND OF THE INVENTION The present invention relates broadly to the art of constructing bituminous layers.
More particularly this invention relates to the art of road, street or highway construction.
The construction of roads, streets, highways and the like with lateral margins, shoulders, curbings and gutters. hereinafter, for convenience, referred to as abutments, has always presented technical and economical problems. For decades only one method was practical for constructing such lateral abutments. Slabs, rocks, or cobblestones were placed in a mortar bed along the sides of the road, street or pavement surface. This method naturally results in the formation of a joint or gap between the roadway and the lateral abutment, representing a weak point as far as the construction is concerned. This joint or gap is subjected to a particularly great degree of strains and destruction by varying climatic conditions. On the other hand, there are also drawbacks of an economic nature. Although the lateral abutments consisting of natural stone, rock, slabs, etc. are decorative, they are expensive with respect to the material costs alone. What is even more important is that they have to be put in place by hand which is a time consuming and laborious undertaking. Even when natural stones are replaced by the somewhat cheaper cement concrete elements, the joint between the roadway and lateral abutment still remains as a zone of weakness in the construction. Further, it is expensive to place the cement concrete elements in place.
In connection with constructing road surfaces made of ce ment concrete, it has been proposed to construct water gutters and curbings simultaneously with the construction of the road surface in one work sequence. In order to accomplish this, suitable forming or shaping means should be provided on the vibrating board of the concrete finisher. However, this method presents difficulties in practice.
This proposition did not appear to be feasible for processing bituminous mixes. Rather, bituminous abutments, for example bulges or raised marginal ribs, were always constructed separately by means of special finishers either prior to or after laying of the road surface. While this type installation of the abutments by means of machines may facilitate saving in time and costs. it still leaves various problems unsolved. Thus, the choice of profiles for this type of construction of lateral abutments is very limited, and it would not be possible in this manner, for example, to construct water gutters as the lateral margins of the roadway. Besides, the finisher must be fed in a separate work stage and with a specially made mix. Lastly, this method also will leave a joint between the roadway and the lateral abutment, although the same is left only in the form of a construction joint.
A modification of the above described installation by means of a machine is the employment of special finishers that move on tracks. These finishers offer an improvement insofar as it is possible to install several types of profiles, for example, also water gutters. But a drawback exists in that such an operation requires the costly step of prior installation of the tracks. Another drawback is that the finisher must be fed in a separate work step. Here again there occurs a joint between road surface and abutment.
SUMMARY OF THE INVENTION The invention has for an object to provide a method for constructing bituminous layers having profiled lateral abutments of bituminous mix which includes continuously laying and compacting a bituminous mix in a manner to obviate the above described drawbacks of the known methods.
A particular object of the present invention is to construct a bituminous layer and a shaped abutment of bituminous mix in the same work sequence or step without the formation of a joint between the laid-out layer and the abutment.
The invention also relates to a finisher for carrying out the method.
According to this invention the method is characterized such that the installation of the mix for the layer and for the lateral abutments is carried out in the same working step or stage in that the mix is laid out and precompacted so that it is shaped to form a profile in the area of the abutments simultaneously with the laying out of the mix in the area of the layer. While the mix used may be a so-called cold mix which can be prepared and processed according to techniques known per se, it is generally preferred to lay out a hot mix. The
said mix mostly having a temperature of at least C., when using tar bitumen or at least 1 15 C. when using straight run bitumen in said mix of the abutment is preferably subjected to a second precompaction.
ln carrying out the inventive method, the shaped and precompacted abutment can be brought to the density intended for the roadway by means of a final compaction. Moreover, the layer and the abutment can be laid out according to the conventional method for installing successive superposed layers. It does not matter in such technique whether the base layer and surface layer are laid out immediately one after the other or by means of a two-stage operation, that is to say, with a longer time interval between installation of the base layer and the surface layer. It is preferable to utilize the method of this invention at the time when the base layer is being laid out thus obtaining an optimal side abutment during this phase. The method of the invention can also be utilized where it is desired to later reinforce existing roads, making it unnecessary to remove or repair already existing abutments, since the same can be covered with or built into a new abutment.
The inventive method allows construction of convex profiled abutments, for example, side bulges or curbings, as well as concave profiled abutments, for example water gutters or troughs. Furthermore, it is possible according to this invention to form the types of lateral abutments which comprise at least one convex or bulge-shaped profile portion and at least one concave or trough-shaped profile portion.
A bituminous hot mix is preferred as the mix for the inventive method as it is defined, for example, in the specifications of the Swiss Standards Association for hot mix bases and surfaces (see for example, specification SNV/4042la, 4043011 and 40432a). The preparation and laying out of these types of mix can be carried out in the manner customarily used for this type of mix. For example, the bituminous mixtures are prepared at a plant where all materials are heated and the required amounts of bituminous material, sand and stone of different sizes are mixed in a pug mill and while still hot are delivered to the road or street site.
Constructing the profile of the abutment according to the method of this invention is carried out under precompaction, for example, by means of conventional vibrators. Preferably, the profiled abutment is subjected immediately after the first precompaction to a second precompaction which can also be achieved with the aid of conventional vibrators in a similar manner.
This second precompaction enables the installing of a profiled lateral abutment which is already so compacted that it can be traveled upon by the conventional rubber tire rollers practically without changing the form of the profile, the same being, for all practical purposes, as strongly compacted as the roadway, thus receiving almost the same stability as the roadway.
If desired, the profiled lateral abutment can be sealed in customary manner. One can also use for the roadway or the abutment, respectively, a variable mix, for example, a differently colored mix.
A particular advantage of the inventive method is that it can be carried out with conventional finishers utilizing the following described additional equipment. In carrying out the method it is preferred to use a finisher of the conventional caterpillar thread or pneumatic-tire type and which is additionally characterized by a lateral profiled guide plate which is attached laterally at the main smoothing plate and in which the bottom of said lateral profiled plate is shaped to form the profile of the lateral abutment. This lateral profiled plate is equipped with means for precompacting the mix for the lateral abutment, for example, conventional vibrators. Furthermore, the finisher preferred for carrying out the inventive method preferably includes at least one profiled drag plate which follows the lateral profiled guide plate, the former being, for example, mechanically connected with the latter. The said drag plate having the same profile and likewise including means for precompacting the mix, namely, one or more vibrators of conventional construction. Either one or both of the lateral profiled plate and the drag plate can be provided with heating means operable to heat their bottom or base and to impart to the bituminous mix additional heat.
BRIEF DESCRIPTION OF THE DRAWINGS Further and more specific objects and advantages of this invention will be more readily apparent from the following description when taken in connection with the accompanying drawings in which:
FIG. I is a fragmentary schematic view illustrating a finisher for carrying out the method of this invention; and
FIGS. 2 to 4 are fragmentary cross-sectional views respectively illustrating difierently shaped lateral abutments obtained in accordance with this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a conventional finisher 4 including a smoothing or spreading plate 5, a lateral profiled guide plate 1 and a profiled drag plate 2. The lateral profiled guide plate 1 is connected to the smoothing or spreading plate 5 of finisher 4 by means of a hinge joint 6 so that the angularity or transverse inclination of the lateral profiled guide plate can be adjusted or varied independently of the angularity or transverse inclination of the basic machine. For the purpose ofsetting or adjusting the transverse inclination of the lateral profiled guide plate I, there is provided an upright or post 71 on the finisher 4, a similar upright or post 72 on lateral profiled guide plate 1, and a spindle means 74 pivoted to each post and connected by a rotatable adjusting nut 73. This arrangement being similar to a turnbuckle. For the purpose of distributing the mix in the area of the roadway surface to be constructed and in the area of the profiled lateral abutment, there is provided a distributor helix or screw 11 of a conventional type. The bottom of the lateral profiled guide plate 1 is provided with a thick metal wear plate, forming smoothing bottom 8. There is further provided a vibrating means 9 of conventional type on said lateral profiled plate and a vibrating means 55 on the smoothing plate 5. The vibrating means 9 together with front wall 10, whose inclination can be varied, causes the mix to be precompacted and form the profile determined by the shape of smoothing bottom 8. The angular position of the front wall 10 of the lateral profiled plate as well as the angular position of the front wall 41 of finisher 4 can be selected or adjusted, respectively, according to the flow of material. Feeding the mix proceeds from finisher 4 with distributor helix 11 which is laterally extended beyond the basic machine for the purpose of conveying the mix. An outer sidewall 12 on the lateral profiled plate 1 prevents lateral escape of the mix. This ensures that the mix remains true to form and that it is precompacted in the area of the lateral abutment. In the lower portion of sidewall 12 there is provided a displaceable slide plate 13 so that the lower edge of sidewall 12 can be adjusted higher or lower by means of turning spindles 121 by handles or levers 122. The slide sheet 13 is delimited at its bottom surface by means of a laterally extending metal sheet 131. Sidewall 12 is provided with front and rear transversely extending metal sheets 124 and 125 for the purpose of providing a mechanical reinforcement and these front and rear metal sheets are interconnected by a longitudinal support means 123.
The profiled drag plate 2 is connected to lateral profiled guide plate 1 by a linkage I6. This linkage 16 is yieldingly and hingedly connected to the plate 1 by a connecting member 15. Preferably there is also provided a similar yielding or hinged connecting member at the point of connection between linkage 16 and drag plate 2. This connection is not shown.
A nonrigid connection between guide plate 1 and drag plate 2 is useful in order to assure on the one hand that the drag plate 2 rests fully or heavily on the surface being shaped and that, on the other hand, there will be faithful adherence to the profiled shape being formed even when there are slight curvatures involved.
If desired, a universal joint-type or ball-type coupling could be provided between the opposite ends of the linkage l6 and the plates 1 and 2.
The drag plate 2 is equipped with a smoothing bottom 17 which is of similar construction as and has the same profile or shape as the smoothing bottom 8 of guide plate 1. This bottom 17 also consists of a plate which is wear-resistant, replaceable and shaped to correspond to the shape of the desired roadway abutment. FIGURE 1 shows the laying out of a water gutter 3 as a lateral abutment of a roadway 31. Two vibrators 19 of a conventional type are mounted on drag plate 2. The front wall 18 of plate 2, not seen in the drawing, is slightly rearwardly inclined. At the lower portion of the outer sidewall 20 which prevents the mix from squeezing out laterally and thus assures adherence to the shape being formed during the precompacting action, there is provided a displaceable slide sheet 21 with a lower laterally extending metal sheet 211. The slide sheet 21 can be displaced vertically by turning spindles 201 by levers or handles 202, so that the height of the side surface 14 of the lateral abutment can be varied in the same manner as is the case when adjusting the slide sheet 13 on the lateral profiled plate 1. In order to prevent the hot bituminous mix from sticking or adhering to the apparatus and to provide for a better compaction, either or both of plates I and 2 can be heated, for example by means of heating means such as at 22, 22 Said heating means can be, for example, an oil burner or an electrical heating device.
The vibrators 9, l9 and 55 can be mechanical or electrical vibrators, preferably enabling a continuously variable regulation of the intensity or degree of compaction by controlling the frequency of and/or the amplitude of the vibration imparted by the vibrators. The power for the vibrators and for the heating means is furnished either by means of a separate power unit or from the generator of the basic machine.
The vibrators 55 and 9 are preferably set such that the density of the roadway and abutment which are obtained at the trailing end of plate 5 and at the trailing end of plate 1 are approximately equally great, amounting to, for example, approximately percent of the final compaction. The vibrators 19 on drag plate 2 are preferably set such that the compaction obtained in the area of the shaped lateral abutment 3 at the trailing end of drag plate 2 is so high that the lateral abutment 3 can be subjected to its final compaction by rolling without significantly altering the shape of or damaging the profile of the abutment.
The exact working conditions, particularly as far as the working speed, intensity of vibration and temperature of the laying out operation are concerned, can be coordinated in a known manner. For example, one can obtain a work speed or rate of 5 to 25 m/min with the above described finisher apparatus. In such operation, the vibrator frequency can likewise lie in the customary range of 50 to 60 Hz. if one works with normal temperatures proceeding from the mixing installation, for example, at approximately l35 C. to 170 C. with the use of straight run bitumen. The temperature of the mix at the beginning of the first precompacting phase should not be more than 20 C. below the temperature attained by the mix when it left the mixing installation or pug mill. With the use of tar bitumen, one can work with somewhat lower temperatures at the mixing installation, for example, 1 10 C. to C. As a rule, the viscosity of the binding agent of the mix, the temperature of the mix being layed out and the degree of compaction obtainable by the vibrators are interrelated and the optimum working conditions can be determined by means of simple experiments. For the final compacting phase of the roadway, one suitably uses the known smoothing and rubber wheeled rollers. For the final compacting phase of the lateral abutment, isostatic pneumatic rollers are preferred because they facilitate a relatively uniform and high final compaction while at the same time, preserving the true shape. FIGS. 2 to 4 show examples of the profiles of lateral abutments as can be obtained according to the method of this invention.
FIG. 2 illustrates a profile including a bulge or raised rib 32 as a lateral abutment ofa roadway 36. FIG. 3 illustrates a combination bulge or rib 33 and water gutter 34 as the lateral abutment or margin ofa roadway 37. FIG. 4 illustrates a concave or trough-shaped water gutter 35 as the lateral abutment or margin or a roadway 38.
The profile shapes depicted in FIGS. 2 to 4 are merely exemplary, and it is possible to make other and different profile shapes. Profile shapes having extreme sharp edges or profile shapes all vertical surfaces are less lateral Preferably the width to the invention of the profile is at least of equal size as that of the height ofthe profile.
As can be seen from FIGS. 1 to 4 no joint whatsoever is formed between the lateral abutment and the roadway. It must be particularly stressed that it is possible to add all types of the profiled lateral abutments obtainable according to this invention to a preexisting lateral terminal edge of a road having a vertical or inclined surface. All that is necessary to do in this case is to merely raise the slide sheets 13 and 21, respectively, of the lateral profiled guide plate 1 and profiled drag plate 2, respectively. Constructing the profile of the abutment between this preexisting lateral terminal edge and the roadway can then be performed in the same manner as described above.
The apparatus depicted in FIG. 1 can be constructed symmetrically, that is to say, the finisher 4 is then equipped at both sides with one each of a lateral profiled guide plate and a profiled drag plate connected thereto. This makes it possible to construct in a single work sequence a roadway with profiled lateral abutments at both sides.
If desired the method and the apparatus of the invention, with suitable modifications, can also be used for constructing bituminous layers having profiled lateral abutments or margins other than roadways, for example, for the construction of walkways, plazas, terraces or dam constructions.
As indicated above, this invention is not to be limited to the construction of roadways. Therefore, in the appended claims, the term layer" is used in a generic sense to mean any layer formed of bituminous mix that can have a lateral abutment area shaped and precompacted, regardless of whether the applied layer is later covered with a thinner covering layer or not, or in itself constitutes an actual road or pavement surface.
It should be apparent from the foregoing detailed description, that the objects set forth at the outset to the specification have been successfully achieved. ACCORDINGLY,
What is claimed is:
l. A nonrail-bound apparatus which may be used directly on the ground for simultaneously constructing a bituminous mix layer having a profiled lateral abutment comprising a finisher including means for laying out and precompacting an area of said bituminous mix layer, at least one profiled guide plate laterally connected to said first-mentioned means, said guide plate including a bottom shaped in accordance with the profile desired for said lateral abutment, means operably associated with at least said guide plate for precompacting the mix underlying said shaped bottom, a profiled drag plate including a bottom shaped in correspondence with the shape of said bottom of said guide plate, means connecting said drag plate to said guide plate in trailing relation therewith, means operably associated with said drag plate for precompacting the mix underlying its shaped bottom, means connecting said drag plate to said guide plate including components permitting said drag plate to move relative to said guide plate, said guide plate and said drag plate including means for heating the shaped bottoms of said guide plate and said drag plate, and hinge means laterally connecting said guide plate to said laying out and precompacting means ofsaid finisher.
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