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US-12618202-B2 - Method for renovating a roadway and machine for simultaneous spreading of fibres and bitumen emulsion

US12618202B2US 12618202 B2US12618202 B2US 12618202B2US-12618202-B2

Abstract

In a method for renovating a roadway, a first tack coat including a bitumen emulsion, a second coat of fibres and then a third surface coat that is a “clean” bitumen emulsion or includes an anhydrous asphalt binder, is spread by a spreading machine from bottom to top and overlaid on the milled or planed roadway. The fibres are sprayed onto the tack coat and the sprayed fibres having a maximum length of 12 cm, an asphalt mix being subsequently spread over the surface coat, the residual binder of the “clean” bitumen emulsion having a penetrability of less than 40 dmm and a ball-ring temperature greater than 50° C., the ‘clean’ bitumen emulsion including between 30% and 70% bitumen, between 30% and 70% water, and between 0.1% and 10% surfactants, stabilisers and/or additives, the percentages being by weight. The application also relates to a spreading machine.

Inventors

  • Nelson K. WESENBERG
  • Jean-Paul Fort

Assignees

  • COLAS

Dates

Publication Date
20260505
Application Date
20210504
Priority Date
20200505

Claims (20)

  1. 1 . A method for renovating a vehicle traffic pavement, the method comprising the following steps: a first step of spreading in order to obtain a lower bituminous tack coat; then a second step of spreading fibers in order to obtain an intermediate coat of fibers; then a third step of spreading in order to obtain an upper bituminous surface coat, the first step of spreading, the second step of spreading, and the third step of spreading being executed during a single passage of a spreading machine on the vehicle traffic pavement to renovate, the fibers being sprayed on the lower bituminous tack coat, the sprayed fibers having a maximum length of 12 cm (4.7 inches); a subsequent step in which the surface coat is covered with a bituminous asphalt, wherein the surface coat is a coat of trackless bitumen emulsion or the surface coat includes an anhydrous bituminous binder, wherein the trackless bitumen emulsion includes hard bitumen, the trackless bitumen emulsion providing a residual binder once a breaking of the emulsion is obtained, the residual binder of the trackless bitumen emulsion having the following properties: a penetration grade lower than 40 dmm (0.157 inches), and a Ball-Ring temperature higher than 50° C. (122° F.), wherein the trackless bitumen emulsion includes from 30% to 70% of bitumen, from 30% to 70% of water, from 0.1% to 10% of at least one surfactant and at least one additive, the percentage being in weight, wherein the anhydrous bituminous binder comprises oils able to evaporate, and the anhydrous bituminous binder has the following properties after evaporation of the oils: a penetration grade lower than 40 dmm (0.157 inches), and a Ball-Ring temperature higher than 50° C. (122° F.).
  2. 2 . The method according to claim 1 , wherein the residual binder of the trackless bitumen emulsion has the following properties: a penetration grade lower than 20 dmm (0.78 inches).
  3. 3 . The method according to claim 2 , wherein the trackless bitumen emulsion includes from 30% to 70% of bitumen, from 30% to 70% of water, from 0.1% to 3% of at least one surfactant, at least one stabilizer, and at least one polymer additive, the percentage being in weight.
  4. 4 . The method according to claim 2 , wherein the lower bituminous tack coat includes one of the trackless bitumen emulsion and the anhydrous bituminous binder.
  5. 5 . The method according to claim 3 , wherein the lower bituminous tack coat includes one of the trackless bitumen emulsion and the anhydrous bituminous binder.
  6. 6 . The method according to claim 1 , wherein the trackless bitumen emulsion includes from 30% to 70% of bitumen, from 30% to 70% of water, from 0.1% to 3% of at least one surfactant, at least one stabilizer, and at least one polymer additive, the percentage being in weight.
  7. 7 . The method according to claim 6 , wherein the lower bituminous tack coat includes one of the trackless bitumen emulsion and the anhydrous bituminous binder.
  8. 8 . The method according to claim 1 , wherein the at least one additive is selected from stabilizers, anti-freezing agents, thickening agents, polymer additives, pH-modifying agents, and adhesivity dopes, wherein the polymer additives are selected from natural latex, styrene-butadiene-styrene (SBS), styrene-butadiene-rubber (SBR), ethylene-vinyl acetate (EVA), wherein the adhesivity dopes are selected from alkyl-polyamines, alkyl amido-polyamines, and alkyl imidazo-polyamines, and wherein the pH-modifying agent is hydrochloric acid.
  9. 9 . The method according to claim 1 , wherein the lower bituminous tack coat includes one of the trackless bitumen emulsion and the anhydrous bituminous binder.
  10. 10 . The method according to claim 9 , wherein the trackless bitumen emulsion has the following properties: Saybolt-Furol Viscosity @ 25° C., secs: 20-150, sieve non-passing fraction, % Max.: 0.3, demulsibility, % Min.: 40, and storage stability, % Max: 1.
  11. 11 . The method according to claim 1 , wherein the fibers are selected from glass fibers, synthetic fibers, and organic fibers.
  12. 12 . The method according to claim 1 , wherein the residual binder of trackless bitumen emulsion has the following properties: residue by distillation at 177° C. (350° F.) [oil distillate, % max]: 3, and solubility %, Min.: 97.
  13. 13 . The method according to claim 1 , wherein the lower bituminous tack coat is applied at a dosage of 1.125 kg/m 2 +/−0.675 kg/m 2 (0.25 Gal./SY+/−0.15 Gal./SY) and the surface coat is applied at a dosage of 1.125 kg/m 2 +/−0.675 kg/m 2 (0.25 Gal./SY+/−0.15 Gal./SY), and wherein the fibers are glass fibers and the glass fiber coat is applied at a dosage of 75 gr/m 2 +/−45 gr/m 2 (2.2 oz./SY+/−1.3 oz./SY).
  14. 14 . The method according to claim 1 , wherein, before the first step of spreading, the surface of the vehicle traffic pavement to renovate is milled or planed in order to detach surface materials from the pavement, and the detached materials are removed from the vehicle traffic pavement to renovate.
  15. 15 . The method according to claim 14 , wherein a resulting milled or planed vehicle traffic pavement includes parallel grooves, the parallel grooves being elongated along a vehicle traffic pavement length direction, and wherein the bitumen emulsion and the fibers are spread in a sufficient quantity to obtain a uniform surface.
  16. 16 . The method according to claim 1 , wherein the anhydrous bituminous binder is hot spread.
  17. 17 . The method according to claim 1 , wherein the at least one additive comprises at least one stabilizer.
  18. 18 . A spreading machine for simultaneously spreading fibers and bitumen emulsion for a vehicle traffic pavement renovation method, the machine comprising: a reserve of fibers; a bitumen emulsion tank containing a trackless bitumen emulsion; and a bitumen emulsion and fiber spreading system including a first bitumen emulsion spreading boom, a fiber spraying device, and a second bitumen emulsion spreading boom, the first and second bitumen emulsion spreading booms including nozzles, the first bitumen emulsion spreading boom, the fiber spraying device, and the second bitumen emulsion spreading boom being disposed to spread successively and superimposed, during travel in a single passage of the spreading machine on the vehicle traffic pavement to renovate, a lower bituminous tack coat comprising bitumen emulsion sprayed by the first bitumen emulsion spreading boom, then an intermediate coat of fibers comprising fibers sprayed by the fiber spraying device, said sprayed fibers having a maximum length of 12 cm (4.7 inches), then an upper bituminous surface coat comprising bitumen emulsion sprayed by the second bitumen emulsion spreading boom, to bind the sprayed fibers between two coats of trackless bitumen emulsion, the trackless bitumen emulsion containing hard bitumen, the trackless bitumen emulsion providing a residual binder once a breaking of the emulsion is obtained, the residual binder of the trackless bitumen emulsion having the following properties: a penetration grade lower than 40 dmm (0.157 inches) and a Ball-Ring temperature higher than 50° C. (122° F.), and the trackless bitumen emulsion includes from 30% to 70% of bitumen, from 30% to 70% of water, from 0.1% to 10% of at least one surfactant and at least one additive, the percentage being in weight.
  19. 19 . The machine according to claim 18 , wherein the fibers are glass fibers, the fibers are in the form of continuous fibers in the reserve of fibers, and the fiber spraying device includes a set of modules, each of the modules including two nozzles and a tool for pulling the continuous fibers, chopping the continuous fibers, and spraying the chopped fibers towards the pavement.
  20. 20 . Machine according to claim 18 , wherein the at least one additive comprises at least one stabilizer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the U.S. national phase of International Application No. PCT/EP2021/061759 filed May 4, 2021 which designated the U.S. and claims priority to FR Patent Application No. 2004460 filed May 5, 2020, the entire contents of each of which are hereby incorporated by reference. TECHNICAL FIELD The present invention generally relates to the field of construction and maintenance of traffic pavements and more particularly relates to a method for renovating a traffic pavement as well as a spreading machine configured to implement the method. The concerned traffic pavements are essentially road traffic pavements but the invention can find applications for any type of flooring such as, for example, runways, harbour quays, sport surfaces, car parks, cycle paths. TECHNOLOGICAL BACKGROUND Certain traffic pavements may be degraded and generate more or less extended cracks at their surface. The causes of these cracks may be multiple, in particular road traffic extent and/or the structure, including the pavement base. These cracks may be directed perpendicular to the pavement length, which may for example be due to the fact that the pavement includes a coat of bituminous asphalt that has been spread over a structure consisted of concrete slabs separated by joints, the cracks occurring in alignment with the joints. The cracks may be directed along the pavement length, which may for example be due to the fact that the pavement verges are not stabilized. The cracks may also be a result of a poor adhesion between the layers constituting the pavement. Finally, the cracks may be generated by the thermal contraction of the pavement materials. Anyway, these cracks are a cause of increased speed of pavement deterioration and it is thus important to seal them and, above all, to prevent them from reappearing on the surface. It is also desirable that the methods implemented for that purpose are simple, fast and inexpensive. Conventionally, to repair the degraded pavements, the pavement surface is milled to eliminate a determined surface thickness of the degraded pavement, the materials issuing from this milling are eliminated, then one or several new coats of materials are applied. This rehabilitation method being expansive, it may be chosen to apply directly the new pavement layer(s) on a geotextile membrane placed on the existing pavement and preventing/slowing down the rise of cracks. Documents EP 0 456 502 A2, FR 2 661 929 A1 and EP 1 624 110 A2 are known in the field of the invention. In this latter document EP 1 624 110, it has been proposed to apply on the existing cracked pavement a membrane made in-situ and consisted of a coat of a bituminous binder, then a coat of glass fibres chopped and sprayed in-situ, then a coat of a bituminous binder, then a gravel spread, intended to protect the membrane from the traffic of the construction machines applying the surface asphalt coat that is subsequently implemented on this membrane. This gravel spread may however affect the quality of bonding of the asphalt coat to the membrane. Moreover, tack coats consisted of bitumen emulsions are used to ensure bonding between the layers of a pavement structure in order to ensure the structural integrity and thus sustainability thereof. Indeed, the quality of this bonding is essential to pavement survival, because the latter has been dimensioned for the traffic it is intended to receive, as a structure of layers attached to each other. If layers slide between each other, each of them will be subjected individually to higher deformations and stresses than anticipated and will be rapidly degraded by fatigue, affecting the life duration of the whole pavement. Therefore, the life duration of a pavement dimensioned for 20 years might be reduced to 7 or 8 years if the layers thereof become unstuck from each other. Emulsions for tack coats are traditionally based on “semi-hard” to “soft” bitumen emulsions; but these latter have for drawback, once broken, that their residual binder sticks to the construction machine tyres, affecting the whole binder film and hence the bonding quality, but also causing soiling around the roadwork. Indeed, once the emulsion broken, the 0.3 to 0.6 kg/m2 (0.07 Gal./SY to 0.14 Gal./SY) of residual bitumen adhere to the construction machine tyres, with two negative consequences: firstly, the deterioration of the bitumen film applied over the pavement surface, thus reducing the bonding efficiency and, secondly, the soiling of the adjacent lanes taken by the roadwork traffic. By “half-hard to soft bitumen”, it is meant here a bitumen having a penetrability grade at 25° C., according to the European standard EN-1426 (January 2018) or the American standard ASTM D5 “Penetration of Bituminous Materials” (December 2019), higher than or equal 50 tenths of a mm (dmm), and may correspond, for example, to one or several bitumen materials having the following classes: 50/70, 70/100, 10