LU83321A1 - SELF-PROPELLED MACHINE FOR THE REGENERATION OF ROAD COATINGS IN A BITUMINOUS CONGLOMERATE, USING A COUPLED MICROWAVE RADIO FREQUENCY GENERATOR WITH AT LEAST ONE SLOTTED WAVE-GUIDED ANTENNA - Google Patents

Description

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Self-propelled machine for the regeneration of road surfaces in bituminous conglomerate, using for heating the coating a microwave radio frequency generator coupled with at least one antenna with guide i 5 of slot waves ί | The invention relates to a self-propelled machine i î for the "in situ" regeneration of road surfaces in! bituminous conglomerate, using for heating! * 10 coating a microwave radio frequency generator {coupled with at least one antenna of the slotted waveguide type, capable of irradiating and distributing the energy produced towards the ground.

It is known that, protected from air and light, 15 bitumen retains, practically infinitely, its natural organoleptic and rheological characteristics.

The bituminous conglomerate used for road superstructures, essentially constituted by a hot mixture of inert stones and bitumen, follows at all points the above-mentioned law and essentially retains all the rheological characteristics acquired at the time of its preparation and its spreading over the site.

The deactivation of road coatings I of this type is normally caused by the rupture by wear of the layers bonded by the bitumen. Slots are thus formed through the layers, into which water 1 and dust penetrate, which create diaphragms by which the deterioration process is made irreversible. The extension of the ruptures leads to the formation of ruts and 30 dents and requires repairs which end up! make it necessary to demolish and decommission the layers of coverings. Residues from the demolition of a coating heated by means suitable for; temperatures of their initial preparation (150 ° -180 ° C) and 35 remixed, give bituminous conglomerates having characteristics quite similar to the initial characteristics and produce coatings with an i; · Behavior and resistance almost equal to that of the i "f · first coating.

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Up to now, the "in situ" regeneration of said materials has never been advantageously carried out on an industrial scale because of the difficulty of having heating systems which do not alter the characteristics of the bituminous binder.

It is known, in fact, that bitumen loses all or part of its binding qualities if it is heated to temperatures above about 200 ° C. In addition, heating to these temperatures, if carried out in the presence of air, gives rise to oxidation phenomena which alter the essential properties. With the systems known up to now, since bitumen and inert materials are poor conductors, it is necessary, in order to correctly heat the mass of the fragments, to apply an extended ex-position to indirect sources of heat at low temperature, traditional type, which makes it practically disadvantageous any equipment for the "in situ" regeneration of materials and their reuse for the repair of damaged road surfaces.

20 This explains why, until now, in the case of maintenance operations on the surface of the coating, especially for those which do not concern only the upper part, i.e. the wear layer the method of demolition of the bituminous coating is still applied, for example by milling followed by the displacement and unloading of the demolished materials and the reconstruction of the coating using a new bituminous conglomerate, with all the disadvantages that this entails.

The present invention relates to a self-propelled machine for the "in situ" regeneration of road surfaces, which uses for heating the surface the energy produced by a microwave radio frequency generator coupled with at least one antenna of the slotted waveguide capable of irradiating and distributing the energy 35 produced towards the ground.

This machine is essentially constituted by a self-propelled chassis, preferably mounted on tracks, provided with a motor and driving means on which 5 -p are provided: ^ _ - 3 - - a generator capable of supply at least one microwave radio-frequency regenerator coupled * with at least one antenna of the slotted waveguide type capable of irradiating and distributing the energy produced 5 towards the ground, - devices for the demolition of the part of the road surface previously heated, which one wishes to regenerate, - devices for moving and lifting from the ground the demolished materials, - at least one homogenizing and mixing device for said materials, preferably comprising rotary blades , - a bituminous binder tank connected to a pipe provided with injectors for the provision of any corrective additions inside the homogenizer and mixer device, - a tank for the fillers s, provided with a metering device for the addition of any corrective additions inside the homogenizing and mixing device, - a device for distributing the treated materials which leave the homogenizing and mixing device, - a finishing plate for the spreading and the first compacting of the regenerated conglomerate.

The advantages which can be obtained by using the machine according to the present invention are: the simultaneous heating, at a uniform and perfectly adjustable temperature, of the entire mass subjected to the treatment, avoiding the disadvantage of insufficient of its own thermal conductivity, thanks to the use of the energy emitted by the antenna coupled to the microwave radio frequency generator, "- the adjustment of the depth of the layer of the pavement coating that we want to regenerate, - the reduced dimensions of the heating device compared to those of known devices and, therefore, j greater maneuverability of the whole machine by 4? compared to those already known, tf ^ - 4 - - the "in situ" regeneration of road surfaces which is the subject of maintenance intervention, making it possible to eliminate the cost of milling, loading and unloading of demolished materials, as well as of the supply and placement on the ground of the new conglomerate necessary for the reconstruction of the coating.

In addition, the time required for the operation is extremely reduced and there are no interruptions between the operational phases, so that at the end of the day 10 the whole road can be opened to traffic again. . It is also necessary to take into account the ease of parking the machine on the reserved places along the road, because of its smaller bulk.

Other characteristics and advantages of the invention will become apparent on examining the description and the appended drawings in which a preferred embodiment of the present is shown, by way of indicative but not limiting example. invention.

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FIG. 1 shows, in side view, the self-propelled machine for regenerating road surfaces; in bituminous conglomerate according to the present invention.

FIG. 2 shows, in plan view, the machine Ü of FIG. 1.

Figure 3 shows the machine of Figure 1 125 along the cross section A-A.

Figure 4 shows the machine of Figure 1 along cross-section B-B.

i'i I Figure 5 shows the machine of Figure 1 I i jj along the longitudinal section C-C of Figure 2.

j 30 Figure 6 schematically shows a group || radio frequency generator coupled to a slot waveguide antenna according to the present invention, ij As can be seen in Figures 1 to 5, i] "the self-propelled machine of the invention is essentially i; 35 by a robust chassis 1 mounted on kennels 2, provided with a motor 3 and a cabin 4 comprising the necessary driving means 5.

On said chassis 1 are also provided a generator 6, a fuel tank 7, a tank

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- 5 - see cooling water 8, a liquid reservoir for hydraulic controls and transmissions 9, a bituminous binder reservoir 10 and a charge material reservoir 11.

5 In the interval between the axes between the lateral gerons of the chassis 1, is placed longitudinally a homogenizing and mixing device 12 with rotary blades 13 having an inclination capable of conveying inward the materials which enter through the anterior opening 10 of device 12 and push it towards the posterior unloading opening.

The bottom of said device is placed a short distance from the ground and has at the front a ramp 14 intended to receive and convey to the anterior opening of said device 12 previously heated materials, as will be seen in the following description. , then routed by means of the breakers (rippers) 15, moved towards the longitudinal axis of the machine using the pick-up screw 16 and lifted by the scraper blade 17.

20 During the passage through the device 12, the detached bituminous conglomerate is homogenized and mixed and optionally integrated by adding bitumen and / or fillers? the bitumen is sprayed from above by a plurality of injectors 18 connected to a pipe 19 coming from the reservoir 10, and the charges are supplied in fall by means of a metering screw 20 provided inside the reservoir 11 at height a projection of the reservoir which has on the bottom a plurality of holes which correspond to the orifices provided for this purpose in a part of the upper wall of the device 12.

The materials thus treated by the impulse action of the rotating blades 13 are discharged through the rear opening of the device 12 and distributed by a distribution screw 21, integral with the frame 1, over the entire width of the open cavity by the breakers 15. Then, these materials are spread and made compact by means of a finishing plate 22, also fixed to the chassis 1.

jP The chassis 1 has at the front an angular support 23 capable of supporting at least one group 24 intended for heating a layer of the coating of the pavement in bituminous conglomerate of width equal to the length of the group. or groups 24 and whose action can be adjusted in depth and in temperature.

As can be seen in FIG. 6, each group 24 is essentially constituted by a microwave radiofrequency oscillator 25 coupled, via, a power circulation device 26 with three doors 10 and with coaxial output , to an antenna of the slot waveguide type 27 closed at the opposite end with the aid of a short-circuit plug 28.

The power circulation device 26 is connected to a resistive load 29.

The power generator oscillator 25 is supplied at the voltage desired by the generator 6 and, in the preferred embodiment given by way of non-limiting example, said generator 25 consists of a magnetron operating with continuous waves, mistletoe 20 produces power in the millimeter wave range. A circuit 25 with water circulation 30, supplied by the reservoir 8, is provided for cooling the generator.

The function of the power circulation device 26, of the type used in radio bridges, is to prevent the reflected power, that is to say the part of the power due to the diversity of the transmission constant of the aerial medium and of the materials which constitute the pavement as well as the reflection inside the antenna 27 does not return towards the generator 25 creating a malfunction, but is absorbed by the resistive power load 29.

The antenna 27 is constituted by a slot waveguide, in which each slot 31 constitutes an elementary dipole 35.

The arrangement of the dipoles must be such that the radiation is uniformly distributed over the entire length of the waveguide.

..i ^ · According to another embodiment, one can - 7 - provide a final termination (not shown), that is to say that it could be interesting to reuse the power which does not manage to be irradiated by the antenna.

To facilitate transport of the machine 5 which is the subject of the present invention and with the aim of reducing the field of action of the antenna 27, the latter can be produced in two parts which can be connected by flanges.

As a variant, each group 24 can be produced with two independent antennas arranged symmetrically 10 on the same alignment.

To ensure the safety and above all the protection of the personnel employed, the groups 24 are protected by means of a screed 32 made of modular copper elements which covers the top of the structure, open towards the ground in order to prevent radiation leaks. unwanted.

Said cover 32 can be attached using flexible elements 33, for example a reinforced strip of neoprene and / or similar elements, applied, below the periphery of the cover 32.

If it is desired to accelerate the heating of the bituminous conglomerate without increasing the temperature, provision may be made for the use of a plurality of groups 24 arranged longitudinally one after the other, so as to increase the surface area of the road surface exposed to the radiation. In any event, in the embodiment described, the total length of each group is approximately 4 to 4.5 meters, this length being necessary and sufficient to operate over the entire width of the motorway, while its width is around 30 ron 50 cm.

The machine according to the invention therefore has better cohesion than those using a traditional energy source, such as, for example, those with infrared ray heating batteries, which are much longer and difficult to maneuver, particularly when cornering.

In the embodiment described, a generator 6 has been provided capable of delivering the requested power.

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For the operation of the groups 24, hydraulic cylinders 34 are provided, connected to the support 23 and supplied with the liquid contained in the reservoir 8.

The forward speed of the self-propelled machine 5 thus designed is provided up to four meters per minute. Of course, all the elements which compose it are di-i dimensioned in such a way that the total work is carried out 3 without discontinuity, that is to say that the quantity of bituminous conglomerate heated, smashed, picked up, raised, and which ij 10 enters the homogenizer and mixer device 12, in a certain period of time, determined as a function of the desired forward speed, is such that the same quantity of bituminous conglomerate and of charges can be treated at the same time by the device 12 and therefore unloaded, distributed and compacted, thus achieving total regeneration of the road surface. We highlight the fact that, with the use of heating groups constituted by a radio frequency microwave generator; coupled with a slot waveguide antenna, it is | It is possible to adjust the depth of the heated layer, j and to ensure that, without modifying the temperature or: the speed of advance of the machine, this thickness is! greater than the thickness of the layer which it is actually desired to knock down in order to subject it to the treatment of mixing and homogenization.

Heating a deeper layer than the one to be smashed and treated is advantageous because total or partial heating of the materials that make up the deeper layer allows the welding of possible slits - [; 30 Lely present and / or their compaction, which cannot be achieved with the use of traditional energy sources, the action of which is limited to a thickness of a few centimeters, generally from three to five centimeters.

In addition, the treated upper layer will not simply be glued to the surface of the underlying layer: but ultimately, a perfect bond will be obtained, between the upper layer and the underlying layer, without j for this. appreciably modify the distribution jh of the different particle sizes of the inert elements.

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According to another characteristic of the machine of the present invention, it is provided that the scraper blade 17 and the ramp 14 can be lifted so that the materials displaced by the pick-up and distributing screws 5 and 16, can be directly compacted by finisher 22, without going to; through the homogenizer and mixer device 12, when, according to the exclusive judgment of the operator, such a homogenization and mixing treatment, with or without the addition of fillers or binder, does not appear necessary.

Finally, it should be noted that due to the arrangement of the bottom of the device 12 at a short distance from the ground, the materials which come from the demolition of the repaired coating enter directly into said device without any need for it. to use other mechanical lifting means than the ramp 14, which provides a considerable advantage for speed and for the general economy of work. 1 t /

Claims (9)

1. Self-propelled machine for the "in situ" regeneration of road surfaces in bituminous conglomerate, 5 gui uses for the heating of the coating the energy produced by a radiofrequency generator in microwave coupled with at least one antenna of the guide type d 'slit waves, characterized in that it is essentially constituted by a single self-propelled chassis (1), preferably 10 mounted on tracks (2), provided with a motor (3) and driving means (5 ) on which there are provided: - a generator (6) capable of supplying at least one radiofrequency generator (25), coupled with at least one antenna of the slot waveguide type (27) suscep-15 tible d to irradiate and distribute the energy produced towards the ground,? - devices (15) for the demolition of the part of the road surface previously heated, which one wishes to regenerate, 20. devices (16, 17, 14) for moving and; lifting of the demolished materials from the ground, - at least one homogenizing and mixing device (12) of said materials, preferably comprising rotary blades (13), 25. a tank (10) of bituminous binder connected to a con duct (19 ) provided with injectors (18) for providing any corrective additions inside the homogenizing and mixing device (12), - a tank (11) for the charges, provided with a metering device (20) 30 for the provision of any corrective additions inside the homogenizing and mixing device (12), - a device (21) distributing the treated materials which leave the homogenizing and mixing device (12), - a finishing plate (22) for spreading and first compaction of the regenerated bituminous conglomerate. 2. Machine according to claim 1, characterized in that each group (24) for heating a Γ part of the road surface consists essentially of y *; ^ ai "A microwave radio frequency OSCii'1'atUr (25) (- 11 - coupled, via a three-door power circulation device (26) with coaxial output, to a antenna (27) of the slit waveguide type closed at the opposite end by means of a short-circuit plug 5 (28), in which each slit (31) constitutes an elementary dipole and the arrangement slots is such that the radiation is uniformly distributed over the entire length of the waveguide and by the fact that there is also provided a resistive load (29) connected to the power circulation apparatus (26) and a water circulation circuit (30), supplied by the reservoir (8), for cooling the oscillator (25). 3. Unit for heating part of the road surface according to claim 2, characterized in that the oscillator (25) consists of a magnetron - which operates with continuous waves and which produces power in the range millimeter waves. 4. Unit for heating part of the road surface according to claims 2 and 3, characterized in that the waveguide (27) consists of two parts connectable by flanges. 5. Unit for heating part of the road surface according to claims 2, 3 and 4, characterized in that it is produced with two antennas (25 to 31) mounted symmetrically on the same alignment. 6. Group for heating part of the road surface according to claims 2 to 5, characterized in that it is protected by means of a yoke (32), in modular copper elements which covers the top of the whole assembly, open towards the ground so as to prevent leaks of unwanted radiation, said yoke (32) being extended downwards by flexible elements (33), for example a strip reinforced with neoprene 35 and / or d 'similar elements applied to its periphery. 7. Machine according to claim 1, characterized in that the bottom of the homogenizer and mixer device (12) is disposed at a short distance from the ground, so that the materials demolished by the breakers (15), '"à-" · '- 12 - moved by the collecting screw (16) and joined by the scraper blade (17), enter directly into the homogenizing * and mixing device (12) without it being necessary to use other means mechanical lifting than the! 5 ramp (14) provided below the mouth of said provision! sitive (12). i 8. - Machine according to claim 1, charac- terized by the fact that the scraper blade (17) and the ramp (14) I can be lifted so that the materials demolished by the breakers (15) and moved by the collecting screw (16) is not lifted from the ground and passes below the | homogenizer and mixer device (12). 9. Machine according to claim 1, charac- i terized in that the group or groups (24) provided • • 15 for heating are adjustable in height and orientation by means of jacks (34) oleodynamic control • connected to the support (23). 10. Machine according to claim 1, characterized in that the groups (24) provided for heating are arranged in parallel lines, one after the other. / ..—— Ü ^; j "J y i I · = i! i j 1 t f [