RU2554954C1 - Method of elimination of local depressions on asphalt concrete coating of motor roads - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method of elimination of local depressions on asphalt concrete coating of motor roads includes cleaning of depression, its filling with granulated asphalt concrete mix of bitumen and filler, and formation of local coating. Walls and bottom of pre-cleaned local depression are wetted with combustible liquid and a flat combustible element is placed at the bottom of the depression and above the cleaned local depression a bearing element is placed which has the form of sheet mesh material, and is made, for example, from heat-resistant polymeric fibre and mineral fibre, providing its fixing on the paving, at least, from two opposite sides of the local depression outline with mechanical preload, and then on the bearing element the granulated asphalt concrete mix of bitumen and coarse mineral filler is placed with the layer necessary for depression compensation, and before formation from it of coating by compaction above the local depression the flat combustible element is burnt in it by ensuring its ignition from lighting-up of combustible liquid on the depression surfaces and air supply under the bearing element by its injection by pump.

EFFECT: simplification of technology, decrease of labour input, increase of coating service life.

2 dwg

Description

The invention relates to the field of road construction, in particular to methods for eliminating local depressions on the asphalt road surface. During the operation of roads, defects will inevitably appear on the road surface, arising both under the influence of car traffic and under the influence of natural and climatic factors and the initial quality of the road surface. These primarily include local depressions (depressions, pits), edge destruction, breaks and other coating defects [1].

Known methods for patching the pavement with an asphalt mixture using hot and cold technologies [2].

When using hot technology, the quality of paving is high, but this method of repair depends on weather conditions and the accuracy of adhering to the technology, including hard temperature conditions. To a lesser extent, this effect affects the use of cold bituminous mixtures and materials based on liquid or liquefied bitumen.

When choosing between hot and cold technologies for repairing asphalt concrete coatings, it should be taken into account that the strength and water resistance of cold asphalt concrete prepared on liquid or liquefied bitumen is 2 ... 3 times lower than hot.

Currently patching of pavements is recommended [3] to be performed at air temperatures not lower than + 5 ° C, and in autumn at + 10 ° C. In conditions of lowering the air temperature below -10 ° C, repair of the coating is recommended to be carried out with mixtures based on viscous or liquid road bitumen grade BND-200/300 or SG-130/200. All this necessitates the repair of road surfaces in winter to warm up the defective place, and then place hot asphalt mixture in this place.

However, this method of repair in winter conditions has the following disadvantages:

- heating a defective place requires the use of energy-intensive devices;

- preparation of hot asphalt mixes at the repair site is associated with the use of expensive small-sized plants;

- the delivery of the hot mixture to the place of repair is associated with the inevitable cooling of the mixture, which significantly affects the quality of the coating.

A close analogue of the invention is a method for granulating a hot asphalt mixture and a method for using this mixture for repairing asphalt coatings in winter conditions [4].

In the present invention, a method for granulating a hot asphalt mix is to mix the hot asphalt mix in water at a water temperature of at least 90 ° C at the beginning of the granulation process and at a water temperature of 30 ° C at the end of the granulation process, while further cooling the granular asphalt mix produce in the air.

The very method of using granular asphalt mix for repairing asphalt pavements in winter conditions consists in preparing a cold asphalt mix by mixing granular asphalt mix with a light hydrocarbon thinner of bitumen, at least kerosene, and the percentage of bitumen thinner relative to the mass of bitumen in the composition of asphalt concrete a decrease in air temperature is constantly increasing.

The disadvantages of this method, implemented by cold technology, are:

- the strength and water resistance of asphalt concrete obtained after repair is 2 ... 3 times lower than that formed by hot technology;

- the preparation of cold asphalt mixes is associated with a high consumption of diluent, i.e. kerosene or gasoline, which, after laying in a defective place, evaporates, polluting the environment;

- before laying the cold asphalt mixture in a defective place, heating and priming with bitumen on its surface are required.

The objective of the invention is the combination of the operations of heating and priming with bitumen of the surface of the local recess with the simultaneous plasticization of bitumen asphalt mix to a viscous state directly at the workplace.

This is achieved by the fact that the walls and the bottom of the previously cleaned local recess (pit) are wetted in a known manner with a combustible liquid, for example, kerosene or gasoline, and a flat combustible element, for example, from cardboard, is placed at the bottom of the recess. After above the cleaned local recess, a support element is arranged in the form of a sheet mesh material, for example, of heat-resistant polymer fiber and mineral fiber, ensuring its fixation on the road surface, at least from two opposite sides of the local recess contour in a known manner, for example, using a mechanical preload. Then, a granular asphalt mixture of bitumen and coarse mineral filler is laid on the support element with the layer necessary to seal the recess, taking into account the density of its laying. Then, by igniting a combustible liquid on the surfaces of the recess and supplying air under the support element, a flat combustible element is ignited and burned. The air supply to the combustion zone of a flat combustible element, for example, by pumping, allows it to accelerate its combustion and at the same time heat up the recess surfaces and their priming due to their own bitumen coating. The high-temperature combustion products formed in this way, passing through the porous layer of the asphalt concrete mixture, change the state of bitumen of the asphalt concrete mixture from solid to liquid on the surfaces of its granules and the viscous fluid of its remaining mass and, as a result, create favorable conditions for the formation of a high-quality local coating. When implementing this technical solution, it is necessary to take into account the following features that the combustion process of a flat combustible element proceeds in self-regulation mode due to self-compaction of the asphalt concrete mixture when high-temperature combustion products pass through its layer and requires 2 ... 3 times less thermal energy than when receiving asphalt concrete.

It is known that the roadbed of roads, as a rule, includes (figure 1, 2) compacted soil base 1, base 2 of crushed stone, stone, concrete, etc. and pavement 3, in particular, in this case consists of an asphalt mixture.

The visual advantages of the proposed method were confirmed by the possibility of its implementation by using improvised tools and materials (figure 1, 2). To do this, on a pavement 3 made of asphalt mixture with a local defect in the form of a depression (pit), it was cleaned using available tools (crowbar, chisel, hammer, brush) with a size of 250 × 250 mm and a depth of 35 mm. The walls 4 and the bottom 5 of the local recess with a brush were wetted with kerosene, and at the bottom 5 of the recess was placed a flat combustible element 6 made of cardboard 4 mm thick. Then, above the local recess, there was a supporting element 7 in the form of a polymer mesh (cell size 3 × 3 mm) with a base thickness of 1.2 mm and a size of 350 × 350 mm, which was fixed on the road surface from two opposite sides of the contour of the recess by preloading it with a load, in this case, bricks. Next, resting on the edge of the wall 4 of the recess and focusing on the flat combustible element 6, a tubular tip 8 with a rubber hose 9 was installed to supply air from the foot drive pump (not shown in Fig. 1) under the support element 7. Then, it was placed on the support element 7 a layer of asphalt concrete mixture 10 in the amount necessary to seal the recess, and ignition of combustible liquid was carried out on the surfaces of the recess 4 and 5 in order to ensure the ignition of a flat combustible element 6 while supplying air through the tip 8 under the support element 7. When burning combustible flat element 6 its combustion products passing through the porous layer of bituminous mixture 10 causes a change in state of asphaltic bitumen mixture from solid to liquid on the surface of bitumen and its rest to its viscous mass. In this case, heating and priming 11 (Fig. 2) of surfaces 4 and 5 of the local recess were also provided. At the end of combustion of the flat combustible element 6, the tubular tip 8 was removed from the recess outward, and then a local coating was formed with simultaneous laying of the free part of the support element 7 in the inner cavity of the recess and the mixture was compacted with a wooden rammer (figure 2).

This method, in fact, combines the advantages of both cold and hot technologies for repairing pavements, namely:

- simplicity;

- low energy intensity and labor intensity;

- implementation at the workplace without the use of expensive devices and materials;

- repair at negative air temperatures;

- increase the service life of the coating after repair;

- environmental friendliness.

Information sources

1. Silyanov V.V. Transport and operational qualities of roads and city streets: a textbook for students. higher textbook. institutions / V.V. Silyanov, E.R. Domke. - 3rd ed., Erased. - M.: Publishing Center "Academy", 2009. - 352 p.

2. www.OS1.ru/article/rood-equipment/2006-5-A-2006-09-29-18-11-55/.

3. Guidelines for the repair and maintenance of public roads. - M.: Rosavtodor, 2004.

4. RF patent for the invention No. 2367630, IPC C04B 26/26, E01C 7/10. The method of granulation of asphalt mixes and the method of using this mixture for the repair of asphalt pavements in winter conditions / B.C. Prokopets, O.A. Rychkova, S.F. Filatov. - Publ. 09/20/2009, Bull. No. 26.

Claims (1)

A method for eliminating local depressions on an asphalt concrete pavement of roads, including cleaning the depressions, placing in it a granular asphalt mix of bitumen and filler and forming a local coating, characterized in that the walls and the bottom of the previously cleaned local depression are moistened with combustible liquid and a flat combustible is placed on the bottom of the depression the element and above the cleaned local recess have a supporting element in the form of a sheet mesh material, for example, of heat-resistant polymer fiber and mineral fiber, ensuring its fixation on the pavement, at least from two opposite sides of the local recess contour by mechanical compression, and then a granular asphalt mix of bitumen and coarse mineral filler is laid on the support element with the layer necessary to seal the recess, and before forming a seal from it over the local recess, a flat combustible element is burned in it by ensuring its ignition from arson of mountains whose liquid on the surfaces of recesses and air under the support member by injecting its pump.

Images