RU2783131C9 - Method for processing and restoring the working properties of joints of rigid airfield and road surfaces - Google Patents

Abstract

FIELD: road construction.

SUBSTANCE: invention relates to a method for processing rigid airfield and road surfaces in order to restore the sealant of the deformation joints of surfaces and prevent their destruction. The self-propelled device is delivered to the surface area to be processed. The operator exposes the device in such a way that the deformable joint to be processed is in the middle of the movable frame, determines the direction of movement with the sight. The operator turns on the compressor, which pre-blows the joint with air, clearing it of debris and dust, a microwave emitter that warms the joint sealant to the required temperature. From the dispenser for the primer, a directed jet is fed to the heated sealant, which adds light fractions to the joint sealant, thanks to which the adhesion and sealing of the joint material with the rigid coating material occurs, and also ensures the spontaneous elimination of minor defects, including a violation of continuity in the sealant itself and the detachment of the sealant from the surface of the cement concrete slab. This is followed by the movement of the device at a given speed along the joint to the next section of heating the joint sealant and primer treatment.

EFFECT: expansion of the range of solutions for restoring the working properties of road and airfield joints.

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Description

The invention relates to a method for processing hard airfield and road pavements at airfields, access roads and roads in order to restore the sealant of the expansion joints of the pavements and to prevent their destruction.

As practice shows, the destruction of the expansion joints of airfield pavements occurs earlier than their standard service life. Destruction begins 2-3 years after the aerodrome is put into operation and most often on the start-finish sections of the runway (RWY), which can lead to emergencies during take-off and landing of aircraft (AC). This fully applies to road surfaces, where the presence of destroyed expansion joints leads to an increase in accidents, a decrease in traffic speed, increased wear of road transport units, etc. [Glushkov G.I., Babkov V.F., Trigoni V.E. Rigid coatings of airfields and highways. M.: Transport, 1994. 349 p.].

Therefore, maintaining the expansion joints of rigid airfield and road pavements in good condition, preventing the destruction of the joint filler - sealant, and maintaining it in working condition is an urgent technical task.

There is a known method of restoring the properties of the sealant of expansion joints of airfield and road pavements, which consists in removing the old sealant mechanically, blowing the joint from sealant residues and dust, treating the joint walls with a primer (a mixture of a rapidly evaporating solvent with bitumen), pouring a new joint sealant with heated mastic. The same operations are carried out during the repair of expansion joints of road surfaces [REGA RF -1994, ODM 218.3.036-2013].

The disadvantages of the known method include: high labor intensity of work, time and material costs, the use of an additional amount of special equipment, a complete stop in the operation of airfield and road surfaces.

At the same time, there are a number of developments in the field of heating dielectric materials with microwave energy, including those with large surfaces. The conducted studies show that there is no negative effect on the physical and mechanical properties of the sealant during microwave irradiation, and the microwave treatment of the organic binder positively affects its physical and mechanical characteristics, which consist in changing the viscosity, increasing the softening temperature, increasing the cohesive strength and adhesion to mineral materials, which leads to an increase in the quality of asphalt concrete [Yadykina V.V., Akimov A.E., Gridchin A.M. Microwave activation of bitumen as a way to improve the physical, mechanical and operational parameters of asphalt concrete. Stroitel'nye materialy. 2010. No. 5. S. 10-12].

A known unit for surface treatment with an electromagnetic microwave field, including a vehicle with a control panel in the cab, a diesel generator installed in the body, and a microwave device for surface treatment (asphalt) on road surfaces (Patent for utility model No. 1524848 dated May 27. 2015).

The disadvantages of this unit are: the use of a motor vehicle, which will lead to excess fuel consumption; low power of the microwave device, which may not always lead to the declared effect of use; inaccurate orientation to the object, since it is impossible to adjust the trajectory of movement due to the fact that the microwave device is located under the body; long time of exposure to the object during heating, the device is not intended for processing seams of airfield pavements.

It is known: the impact of microwave radiation on soil disinfection and weed control and positive simulation of seed germination [patent SU 1474891 A2].

The technical result of the invention is to eliminate the above disadvantages by developing a method for processing and restoring the working properties of an existing old sealant without removing it and replacing it with new sealants, reducing labor and material costs due to performing this type of work without involving additional equipment and people, increasing the efficiency of preparing airfields for flights, as well as the operational and strategic readiness of access roads to airfields.

The specified technical result is achieved by the fact that a method is proposed for processing and restoring the working properties of seams of rigid airfield and road pavements, including cleaning the seam from debris, subsequent heating of the seam sealant to a temperature that ensures its fluidity, and then supplying a metered amount of primer to the heated seam sealant with a directed jet , which adds light fractions to the joint sealant to improve the adhesion and sealing properties of the joint material with a rigid coating material, which is carried out using a self-propelled device moving over the zone of the expansion joint, on the frame of which a compressor is installed to blow the joint and clean it from debris, a microwave emitter, containing a magnetron located in the housing, connected through a waveguide to a pyramidal horn irradiator, an internal shielding insulating grid, and an external insulating belt made of a dielectric material and a primer dispenser are fixed along the lower perimeter.

The proposed method is based on the well-known advantages of using an electromagnetic field of microwave energy (microwave energy) for heating dielectric materials: selectivity of heating, uniformity of heating, volumetric nature of heating, environmental friendliness of heating, high efficiency of conversion of microwave energy into thermal energy. When using microwave energy for processing dielectric materials, it is necessary to take into account the properties of the material being processed at various frequencies and at all stages of the process. The absorbed power and the depth of its penetration into the material are determined by the dielectric constant, frequency and geometry of the microwave system [Handbook on microwave electrothermy / Yu.S. Arkhangelsk. - Saratov: LLC "Scientific book", 2011. - 559 p.].

The essence of the invention is illustrated by drawings, experimental and calculated materials, illustrated by figures 1-4. In FIG. 1 shows a drawing of a self-propelled device for processing seams of hard airfield and road pavements with microwave radiation, in Fig. 2 - the principle of operation of the microwave emitter, in Fig. 3, 4 show the results of experimental and computational studies.

In FIG. 1-4 marked:

1 - metal frame of a self-propelled device with wheels;

2 - power unit of a self-propelled device (containing an electric generator, engine, fuel tank, engine control system);

3 - compressor (for blowing the seam and cleaning it from debris);

4 - microwave emitter;

5 - primer dispenser (for directional primer treatment of joint sealant);

6 - lighting devices on the front panel;

7 - lighting devices on the rear panel;

8 - operator's workplace;

9 - processed coating;

10 - processed expansion joint;

11 - waveguide;

12 - outer insulating belt on the housing of the microwave emitter (consisting of a dielectric material along the lower perimeter of the housing, in the area of contact with the treated surface);

13 - pyramidal horn feed;

14 - seam sealant.

The proposed method can be implemented as follows.

The self-propelled device (FIG. 1) is delivered to the coverage area 9 to be processed. The operator sets the device in such a way that the processed expansion joint 10 is in the middle of the mobile frame 1, determines the direction of movement with a sight, turns on the power unit 2 in which the electric generator is turned on by starting the internal combustion engine, which feeds the microwave emitter 4, the compressor 3. The operator turns on the compressor 3, which preliminarily blows the seam, cleaning it from debris and dust, microwave emitter 4, which heats the seam sealant to the required temperature, from the dispenser for primer 5 with a directed jet, a primer is supplied to the heated sealant, adding light fractions to the seam sealant 14 (Fig. 2) , due to which the adhesion and sealing of the material of the seam with the rigid material of the coating occurs. This is followed by the movement of the device at a given speed along the seam 10 further, to the next section of the seam sealant heating and primer treatment. The self-propelled device moves over the zone of the expansion joint 10 with a given speed mode, moving smoothly at a certain speed from above along the joint 10, the microwave emitter heats it up to a temperature at which the sealing material 14 (Fig. 2) passes into a fluid state. Such a state leads to spontaneous elimination of minor defects, including discontinuities in the sealant itself and separation of the sealant from the surface of the cement concrete slab 9.

To confirm the effectiveness of this method, computational studies and mathematical modeling were carried out, thanks to which preliminary estimates were made of the regime parameters of microwave heat treatment of materials used in the construction of rigid airfield pavements based on the solution of a boundary thermal problem with internal heat sources, the power of which is determined through the given parameters of an electromagnetic wave.

The possible speed and depth of processing of the seam, energy costs are determined in order to show the prospects of the proposed method of maintaining the required quality of expansion joints.

For heat treatment of the sealing material, in which small defects swim in, magnetrons of Russian production M-116-50, with a power of 50 kW at a frequency of 915 MHz, as well as a magnetron M-168, with a power of 5 kW at a frequency of 2450 MHz, can be used. during the fusion process, the primer should be added through a dosing device.

The speed of movement of the installation is calculated using the method of finite element modeling of microwave heating of an expansion joint. Calculations using these magnetrons show that the speed of the radiation source, at which, for given external conditions, the dielectric is heated to a fluid state temperature of -180-190°C, for magnetron I (M-116-50) is 0.02 m/s ( Fig. 3), and for magnetron II (M-168) - 0.005 m/s (Fig. 4). Along the depth of the seam, the intensity of heat release during microwave exposure practically does not change, since the attenuation coefficient of the electromagnetic wave in bitumen is small, and the depth of its penetration, on the contrary, is large. At the same time, the section of the cement concrete slab located in the area of microwave exposure heats up slightly. The cross-sectional dimensions of the horn antenna are calculated depending on the magnetron used. [Dornyak O.R., Nedonoskov A.B. The method of heat treatment of the deformation seam of the airfield pavement using microwave exposure // Aerospace Forces. Theory and practice. 2021. No. 17. pp. 66-75.]

With an increase in microwave power, it is also possible to significantly increase the performance of the device, which will lead to an increase in the speed of movement of the device, which will ensure the achievement of a technical result in a shorter time.

At the same time, biota is destroyed in the seams in the form of grass that destroys the body of the sealant that occurs during the spring-summer operation, which reduces material costs for the fight against plant biomass.

The considered shows that the claimed invention is feasible and ensures the achievement of a technical result, which consists in the development of a new method for restoring the tightness of an expansion joint with minor defects, preventing its premature destruction, thereby increasing the time between repairs, which will allow to obtain an economic effect.

The use of the proposed technical solution will make it possible to apply it at airfields and roads using non-destructive microwave radiation technology, which eliminates minor defects in the volume of the seam and on its surfaces, restores the quality of the expansion joint, reduces labor and material costs, and performs preventive heat treatment of the seam, in which there are no significant defects yet. , but there are prerequisites for destruction, will increase the overhaul life of the coating, in comparison with traditional methods of repair, the proposed technology is resource-saving.

Claims (1)

A method for processing and restoring the working properties of seams of rigid airfield and road pavements, including cleaning the seam from debris, then heating the seam sealant to a temperature that ensures its fluidity, and then supplying a metered amount of primer to the heated seam sealant with a directed jet, adding light fractions to the seam sealant for improving the adhesion and sealing properties of the seam material with a rigid coating material, which is carried out using a self-propelled device moving over the zone of the expansion joint, on the frame of which a compressor is installed to blow the seam and clean it from debris, a microwave emitter containing a magnetron located in the housing, connected through a waveguide with a pyramidal horn feed, an internal shielding insulating grid, and an external insulating belt made of a dielectric material and a primer dispenser are fixed along the lower perimeter.

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