Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
  • E01B1/00—Ballastway; Other means for supporting the sleepers or the track; Drainage of the ballastway
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C11/00—Details of pavings
  • E01C11/16—Reinforcements
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
  • E01B1/00—Ballastway; Other means for supporting the sleepers or the track; Drainage of the ballastway
  • E01B1/001—Track with ballast
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
  • E01C3/00—Foundations for pavings
  • E01C3/003—Foundations for pavings characterised by material or composition used, e.g. waste or recycled material
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D17/00—Excavations; Bordering of excavations; Making embankments
  • E02D17/20—Securing of slopes or inclines
  • E02D17/202—Securing of slopes or inclines with flexible securing means
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
  • E01B2204/00—Characteristics of the track and its foundations
  • E01B2204/03—Injecting, mixing or spraying additives into or onto ballast or underground
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D2300/00—Materials
  • E02D2300/0051—Including fibers

Definitions

• Stabilized structure in particular of the ballast type, and method for stabilizing such a structure
• the present invention relates to a stabilized structure comprising individual separate mineral elements and a method for stabilizing such a structure using a stabilization complex.
• Structures comprising mineral elements are known in various fields such as, for example, the construction of railways and the construction of roads.
• mineral or stony elements for example pebbles from crushed stones of magmatic rocks and certain metamorphic rocks.
• These stony elements can in particular be arranged so as to form a bed of pebbles intended to constitute the ballast of a railway or a base layer in road construction.
• the object of the invention is to find a solution which makes it possible to remedy the drawbacks of structures comprising stony elements of different sizes, in a simple, inexpensive and rapid manner and, at the same time, to preserve the essential properties of the ballasted structure, such as, for example, its ability to distribute loads, its ability to drain and quickly evacuate water.
• the structure comprises a stabilization complex constituted by an added complex comprising a binder and advantageously fibers, and making it possible to maintain the elements of the structure in place.
• the surface mineral elements are partially coated with the added complex, which ensures a bond between them and their immobilization with respect to each other, without affecting their drainage and percolation capacity.
• the present invention also relates to the characteristics which will emerge from the description which follows and which should be considered in isolation or in all their technically possible combinations.
• FIG. 1 is a plan view of an upper surface portion of a railroad ballast showing stabilization means according to l invention
• - Figure 2 is a sectional view of an upper layer of the ballast along line II-II of Figure 1;
• - Figure 3 is a sectional view of a stabilized structure by a variant of stabilization means according to the invention;
• - Figure 4 is a sectional view of a structure stabilized by another variant of stabilization means according to the invention.
• - Figure 5 is a sectional view of a roadway with a reservoir structure incorporating stabilization means according to the invention.
• the tracks for railways are formed of rails fixed on sleepers, themselves immobilized on a ballast 1 composed of stony elements, such as pebbles 2, resulting from the crushing of magmatic rocks or metamorphic, and arranged between the rails and on either side of them.
• a ballast 1 composed of stony elements, such as pebbles 2, resulting from the crushing of magmatic rocks or metamorphic, and arranged between the rails and on either side of them.
• the spreading loose of pebbles 2 at the time of their placement and their arbitrary shapes have the natural effect of creating between them interstices a, b, c, d ... These interstices have a drain function.
• the ballast 1 comprises a stabilization complex 3 constituted by an attached coating which forms a sort of covering net for said pebbles 2 of the upper layers, without altering their drainage and percolation capacity.
• This covering net ensures a connection between the stones and, consequently, their immobilization with respect to each other.
• the stabilization complex 3 of the ballast 1 is constituted by a binder 4 into which fibers 5 are incorporated.
• the binder 4 can be an emulsion of pure or modified bitumen or an anhydrous binder.
• the fibers 5 integrated into the binder 4 to constitute the stabilization complex 3 intended to be attached to the ballast 1 are filiform and of length f at least equal to the distance separating two successive stones 2, for constitute a link between them. All of these links, obtained from stabilization means comprising fibers 51 hereinafter called “long fibers” and of the binder 4, is arranged in a random manner and according to a dosage making it possible to produce a mesh of any shape capable of joining the surface pebbles 2 together, while allowing the drainage of rainwater. through the upper layer of pebbles 2, then their lower layers.
• the ballast 1 comprises a stabilization complex 31 which is constituted by a binder 4 which are integrated fibers 52 hereinafter called "short fibers".
• the length m of the short fibers 52 and the dosage of these fibers during their application are chosen so as to obtain a random blockage of part of the interstices between the stones.
• the binder is retained during its application and forms a mesh of any shape in a manner similar to the first embodiment.
• the long fibers 51 can have a length i ranging from 10 mm to 200 mm
• the short fibers 52 have a length m of less than 1 mm and are in particular micronized fibers.
• the preferred lengths of the long fibers 51 are 25, 50, 90 and 130 mm, the particularly advantageous length being between 25 and 60 mm.
• the life cycle of the maintenance-free ballast can go up to three or even five years, while with traditional ballasts, this life cycle does not exceed one year under the most severe, for example those of high speed lines.
• the stabilization coating has the ability to be easily destroyed during manual or mechanical tamping operations of the ballast, which keeps the ballast its character as recyclable material.
• the stabilization coating also makes it possible to maintain a behavior of a ballasted layer capable of withstanding vibrations when passing train movements. It remains flexible enough to follow the deformations of the support and accept a low amplitude sag.
• the stabilization complex 3 of the ballast 1 comprises, for example, an emulsion of pure or modified bitumen whose dosage is between 1500 and 1800 g / m 2 or an anhydrous binder whose dosage is between 800 and 1200 g / m 2 , and to which emulsion or to which anhydrous binder, are integrated long fibers 51 whose dosage is between 50 and 600 g / m 2 . Examples of dosage of the fiber binder are given below.
• a hydrocarbon binder (based on bitumen) which may or may not be modified by suitable additives (for example: polymers of SBS type), so that that the plasticity interval is large enough to avoid brittleness at low temperature and loss of consistency at high temperature (point ball ring> 50 ° C).
• JD of 1.5 to 3% of SBS polymer in a penetration bitumen given has a viscosity depending on the temperature at the time of spreading.
• Full-scale experiments have shown that a viscosity obtained by spreading the binder defined above at a temperature between 40 ° C and 90 ° C allowed the bonding of the ballast by point on the surface and penetration over a thickness of 1 to 3 ballast pebbles.
• the temperature drops in a time between 0 s and 600 s to a value ⁇ 25 ° C, which allows point bonding of the ballast, irreversible at room temperature, sufficient to prevent stones from flying away when trains pass , but sufficiently weak for a powerful mechanical action by vibration for example, to restore the mechanical independence of each pebble and therefore to rework the geometry of the track by stuffing the ballast.
• room temperature (20 ° C) the tensile stress required to separate two pebbles from the ballast thus glued, is between 50 g / cm 2 and 2000 g / cm 2 at 30 minutes, which is more than enough not to interfere stuffing operations.
• bitumen emulsion offers particularly good results when it has a viscosity of between 0.5 ° and 15 ° Engler.
• the invention also relates to a method using a stabilizing complex to obtain a structure such that it has just been described.
• This process includes a step consisting in forming a sort of net covering the mineral elements of the upper layers of the structure to be stabilized.
• the process can be carried out according to different variants, for example as follows:
• the spreading of the binder film is carried out before the spreading of the fibers
• the spreading of the binder and the spreading of the fibers are carried out simultaneously, so that the binder is mixed with the fibers; the mixing can be done just before the introduction of the binder and the fibers in a spreading applicator.
• the method can consist of either:
• very long fibers 51 are cut in situ by means of a “chopper” type fiber cutter consisting of a rotating cylinder provided with peripheral chopping blades, fed by a loading hopper, such a cutter being associated with a bitumen spreader 4 disposed upstream or downstream of said cutter, on the same running gear.
• a “chopper” type fiber cutter consisting of a rotating cylinder provided with peripheral chopping blades, fed by a loading hopper, such a cutter being associated with a bitumen spreader 4 disposed upstream or downstream of said cutter, on the same running gear.
• precut fibers are brought to the site to be implemented before or after the spreading of bitumen 4, by projection with a gun actuated manually or mechanically.
• the stabilized structure according to the invention can be implemented by the method described above within the limits indicated more top and choosing, for example, an implementation with the following parameters:
• the process can be carried out in the temperature range from + 5 ° C to + 40 ° C.
• the treatment can be carried out on a wet ballast using a bitumen emulsion binder.
• the efficiency of the process is obtained whatever the climatic conditions after implementation within a maximum of 24 hours.
• the invention has been presented as relating to a stabilized structure comprising individual mineral elements, separate, comprising a stabilization complex constituted by an added complex which partially covers the mineral surface elements of this structure and which comprises a binder and fibers.
• the object of the invention can also be achieved by a stabilization complex consisting of a binder alone or, at the very least, by an added stabilization complex comprising no fibers.
• This principle is shown schematically in Figure 4. In this Figure, we see that the elements of the upper layers of the structure to be stabilized are "glued" one to the other by binder pads.
• the detailed illustrative description relates to the stabilization of a structure of the railway ballast type. It should be understood, however, that the invention is not limited to such an application and that it may be used to stabilize any stony structure comprising stone elements. Those skilled in the art can, by routine tests and using the teachings of the present description, determine in each case, according to the nature and the dimensions of the structure to be stabilized, the corresponding characteristics of the binder and of the fibers.
• a stabilized structure is used to allow the circulation of construction trucks which realize the surface layer of a road.
• the implementation of a stabilized structure according to the invention is particularly advantageous, in the field of road applications, in the case of roadways with reservoir structure. Such an application is shown in Figure 5.
• a roadway with a reservoir structure comprises, in addition to the support soil 11 on which it is produced, a form layer 12, a foundation layer 13, a base layer 14 and a surface layer 15.
• the support soil 11, the form layer, the foundation layer and the base layer are separated from each other by interfaces 16, 17 and 18 produced by a geotextile or a geomembrane.
• the stabilization complex 3 is applied to the upper layers of mineral elements of the base layer 14.
• FIG. 5 represents this complex according to the embodiment shown in and described with reference to FIG. 3.
• the stabilized structure can be implemented in the field of road application by using dusting microfibers. These microfibers are only made of organic material and applied, either with guns or with a ramp. Their main effect is to prevent any object or vehicle coming into contact with the newly deposited stabilization complex from sticking.

Landscapes

• Engineering & Computer Science (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Architecture (AREA)
• Mining & Mineral Resources (AREA)
• General Engineering & Computer Science (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Paleontology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Road Paving Structures (AREA)
• Railway Tracks (AREA)
• Machines For Laying And Maintaining Railways (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Discharge Heating (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Nonwoven Fabrics (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9512576

Family Applications (1)

Country Status (9)

Families Citing this family (4)

Family Cites Families (10)

• 1997
  • 1997-10-23 FR FR9713311A patent/FR2770235A1/fr active Pending
• 1998
  • 1998-10-22 JP JP2000518151A patent/JP2001521081A/ja active Pending
  • 1998-10-22 WO PCT/FR1998/002261 patent/WO1999022070A1/fr active IP Right Grant
  • 1998-10-22 KR KR1020007004373A patent/KR20010031365A/ko not_active Application Discontinuation
  • 1998-10-22 EP EP98950178A patent/EP1025312B1/de not_active Expired - Lifetime
  • 1998-10-22 DE DE1998621254 patent/DE69821254T2/de not_active Expired - Fee Related
  • 1998-10-22 AT AT98950178T patent/ATE258253T1/de not_active IP Right Cessation
  • 1998-10-22 ES ES98950178T patent/ES2167289T3/es not_active Expired - Lifetime
  • 1998-10-22 CA CA002307133A patent/CA2307133A1/fr not_active Abandoned

Non-Patent Citations (1)

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