Classifications

• • 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
  • E01C11/165—Reinforcements particularly for bituminous or rubber- or plastic-bound pavings

Definitions

• the present invention relates to the technical sector of public works, more precisely that of the construction and maintenance of roads, motorways, roadways, roadways and the like.
• the roads are coated with a layer of hydrocarbon materials often called “coated”, or “bituminous concrete", this product coming from an oil residue (asphalt).
• the pavements are in the general case (but not limiting) constituted by the support, in general a “coated”, an emulsion layer above the support, as a bonding layer, a reinforcement of the type of 'invention above, and finally a new layer of asphalt about 4 to about 25 cm thick, in one or more layers separated by a thin layer of bonding emulsion.
• ROADTEX and "ROTAFLEX” (brands of the company CHOMARAT) are known.
• ROADTEX type structures consist of an open grid of continuous glass filaments linked by a thermoplastic polymer.
• ROTAFLEX type structures consist of a polyester nonwoven reinforced with a glass grid.
• Patent EP 0 368 600 (Netlon Ltd.) describes a two-layer structure comprising:
• a mesh grid above in particular made of polypropylene, and comprising a thick nodule and not oriented at each junction of strands, and
• an aqueous bitumen emulsion is deposited on the road, then the two-layer structure, then a new layer of bitumen. It is specified that the polypropylene of the grid undergoes a heat treatment during manufacture, to avoid shrinkage during the thermal shock caused by the deposition temperature of the mix.
• the laminate is characterized in that the fabric is combined with the plastic mesh only at the thicker junctions of the mesh and not at the strands of the mesh.
• EP 0 318 707 (Bay Mills Ltd.) is also known, which describes a frame for road surfaces, comprising:
• this adhesive coating can be activated by heat or pressure and forms a bond between the grid and the asphalt.
• This adhesive does not, however, bond the two layers of asphalt on both sides of the grid, which may also be suitable for certain road applications.
• Patent USP 3,581,631 (Enka Corp.) describes an armature which consists of a film comprising threads or filaments, forming meshes which are completely or partially clogged with an adhesive.
• This adhesive is chosen from certain resins and certain polymers having a softening point greater than 50 ° C. and is cast hot on the film. The adhesive, on the one hand wets and "impregnates" the film, and on the other hand is miscible with the bitumen layer.
• the first problem is the need to perfectly bond the different layers forming the structure, that is to say the support (often a mix), the reinforcement and, in general, a top layer (often a mix applied hot to the whole).
• Bitumen emulsions are manufactured in a plant, and consist of liquid or semi-liquid aqueous emulsions applicable by conventional equipment. These emulsions can break as well in 5 minutes as in several hours, depending in particular on the temperature prevailing on the application site. The quality of the bitumen is best adapted to the season and the region, but we cannot produce a different batch for each site temperature.
• the object of the invention is to limit the rise of bitumen through the mesh of grid-type reinforcements.
• bitumen With a grid product such as ROADTEX, a conventional emulsion layer (water and bitumen in a weight ratio of approximately 40 - 60%) is deposited at the rate of approximately 500 g emulsion / m 2 , ie approximately 300 g / m 2 of "residual bitumen". With a grid + nonwoven product such as ROTAFLEX 833, a nonwoven at 80 g / m 2 is used . We must then go up to about 500 g / m 2 of residual bitumen, because it is necessary to impregnate the nonwoven.
• an objective is to be able, despite a complex structure comprising a nonwoven, to reduce the rate of residual bitumen to values of 300 g / m 2 or even 200 g / m 2 , that is to say - say below the usual dosages of the bonding layers. This reduction contributes to the reduction of the bitumen rise.
• the invention resides in the combined use of a fusible product.
• the invention accelerates thanks to a basic treatment the speed of breakage or rupture of the bitumen emulsion, which reduces the downtime of the site and the rise of the bitumen (which is viscous) through the grid.
• the invention applies to any road structure in the broad sense, including areas, runways, airports, etc. comprising at least one hydrocarbon binder, in particular so-called bituminous structures, in particular, but for illustrative purposes only, structures comprising at least minus one layer of asphalt or asphalt.
• the invention relates to a complex reinforcement for road surfacing of the coated or asphalt type, which comprises:
• a fusible product being interposed between the nonwoven and the grid so as to only partially cover the surface.
• the invention therefore provides a three-layer structure where the nonwoven is only partially clogged with the fusible product in order to limit the rise of the bitumen.
• the fusible product fulfills a second function, that of a bonding layer for the final bitumen layer (hot-coated) which will be applied subsequently to the assembly, which makes it possible to significantly reduce the dosage of the bitumen emulsion.
• a preferred manufacturing process consists in preparing the fine nonwoven, and in "sprinkling" the fusible on the nonwoven.
• dust is meant the fact that, by any means of application known to those skilled in the art, the fusible is deposited so as to cover only part of the surface of the nonwoven. The dusting should be as regular as possible, but perfect regularity is not necessary.
• part of the surface is meant the fact that about 30 to 70% of the surface of the nonwoven is covered.
• fine nonwoven is meant a nonwoven of the order of 20 to 80, preferably 20 to 50, preferably 20 to 30 g / m 2 .
• the fusible product will be an EVA (ethylene / vinyl acetate) copolymer.
• the grid is then deposited on the face of the nonwoven having received the fusible.
• the complex according to the invention is placed in such a way that the grid forms the lower face and the nonwoven the upper face.
• the grid / nonwoven assembly traps an air film which will act as a thermal shield against the cold temperature of the lower support, and will therefore optimize the melting of the EVA by the heat provided by the deposition of the upper asphalt layer.
• the nonwoven will preferably be a fine hydrophobic nonwoven, of the polyester or polypropylene type, or glass nonwoven, in particular at about 20 - 50 g / m 2 , or even up to 80 g / m 2 .
• the nonwovens of the prior art are used at around 120 g / m 2 .
• This nonwoven must degrade mechanically by puncturing by the aggregates contained in the mix, due to gravity and compaction (see Fig. 3).
• the fine nonwoven degrades in the event of an open grid; in the case of a tight grid, the nonwoven will be thicker and will be less degraded, or will not be degraded.
• open grid is meant a grid with a wide mesh with respect to the granules contained in the upper asphalt layer.
• the grid will preferably be a grid of glass filaments:
• the mesh of the products will preferably be 5 x 5 mm;
• the invention also relates to a method and an armature making it possible to break the bitumen emulsion more quickly.
• one or more of the elements constituting the complex are brought to a basic pH, that is to say that the grid and / or the nonwoven and / or the fusible is carried, at basic pH.
• the structure according to the invention will be impregnated, either the grid / nonwoven assembly, or, very preferably, the nonwoven deposited on the grid, with a basic agent.
• the basic agent will be any agent or mixture of agents capable of giving the structure a basic character sufficient to significantly accelerate the "breakage" of the emulsion, such as for example the soda ash.
• the emulsion can thus be "broken” almost instantly or instantly. This additional measure saves the site a lot of time during implementation, in particular by not making the teams wait unnecessarily.
• Any basic agent or any mixture of basic agents capable of, or adapted to, meet the criterion of breakage of the emulsion may be used. Such products will be within the reach of the skilled person.
• the basic agent On contact with the bitumen layer deposited on the support, the basic agent acts on the emulsion and effectively, simply and practically causes this emulsion to break or break. Without wishing to be bound by any theory, the Applicant considers that the basic agent deactivates the acid sites of the surfactants used to maintain the stability of the emulsion.
• FIG. 1 schematically shows a sectional view of a representative road structure
• FIG. 2 schematically shows a sectional view of a road structure comprising the frame according to the invention. This figure is intended to represent the order in which the various elements are positioned. The final structure obtained is shown in Figure 3.
• FIG. 3 schematically represents in section the final structure obtained when the elements of the invention are available in accordance with FIG. 2.
• ground base layer consisting of flattened compacted pebbles
• FIG. 1 describes a conventional road structure when a reinforcement is incorporated.
• a thin bonding layer (emulsion) 3 is deposited, then a coating layer 4 which forms the "serious bitumen".
• This layer will receive the wearing course 5 which consists, in its simplest form, of a thin layer of emulsion 6 on which the reinforcement 7 is placed, after which the final coated layer 8 is deposited.
• One or more layers of asphalt 8 superimposed on the grid are applied, depending on the type of road structure.
• the the highest asphalt layer is called the wearing course.
• the asphalt layers are then bonded together by a thin bonding layer of the layer 6 type.
• the invention also applies to such variants.
• FIG. 2 represents the order of arrangement of the elements according to the invention.
• the bonding emulsion 6 is deposited on the serious bitumen 4.
• This emulsion in accordance with an important advantage of the invention, will preferably be dosed at only 200 - 300 g of residual bitumen per m 2 .
• the complex 7 according to the invention is then deposited, for example manufactured as described above.
• This complex consists of the grid 22 and the fine nonwoven 20, the latter carrying on its underside the fusible 21.
• the coated layer 8 is then deposited (or the first layer if there must be several), which contains pebbles 23.
• the temperature means that the water of the emulsion 6 can escape.
• FIG. 3 represents the final state of the road structure, after the sequence shown in FIG. 2. It can be seen that the stones 23 of the asphalt 8 have penetrated between the strands of the grid 22, through the fine nonwoven 20 , and if necessary by tearing it, possibly until it comes into contact with the bonding layer 6 which has itself been at least softened by the heat and therefore has been at least partially integrated into the assembly. It has not been possible in practice to represent the fusible 21 which has melted and has been integrated into the assembly at the level, substantially, of the nonwoven. The whole forms a structure of which all the layers are perfectly integral.
• the invention also relates to a method of reinforcing road structures, characterized in that it is deposited on the layer bitumen emulsion covering the serious bitumen, a reinforcement as described above, then a coating layer, and also, as a particular variant of implementation, the method of reinforcing road structures described above, characterized in that one or more upper layers of asphalt are deposited, each layer being linked by an intermediate layer of bitumen emulsion.
• the invention relates in particular, according to a preferred embodiment, the method of reinforcing road structures which consists in unwinding the complex prefabricated reinforcement according to the invention on the emulsion layer covering the serious bitumen.
• the various elements of the complex framework can also be unrolled separately on the site.
• the nonwoven may have been previously impregnated with a basic agent, or may contain a basic agent in the mass. It is also possible to incorporate the basic agent into the fusible deposited on the nonwoven.
• a basic agent can be deposited on the grid or on the nonwoven as and when it is unrolled.
• the invention also relates to a method for reinforcing road structures, characterized in that at least one layer of asphalt is deposited on the reinforcement, or characterized in that several layers of asphalt are deposited on the reinforcement, each layer being separated by a bonding layer of bitumen emulsion.
• the invention also relates to a method for reinforcing road structures, characterized in that a 200 to 300 g / m 2 emulsion of residual bitumen is used as the lower bonding layer of bitumen emulsion.
• the invention also relates to a method of reinforcing road structures according to which a nonwoven is used (possibly alone on certain sites) or any type of a complex frame of the grid type, possibly comprising a nonwoven or a structure.
• a nonwoven is used (possibly alone on certain sites) or any type of a complex frame of the grid type, possibly comprising a nonwoven or a structure.
• analogous characterized in that said nonwoven is worn, or one or more of the elements constituting the complex of the type grid at a basic pH capable of accelerating the breakage or rupture of the lower bitumen emulsion.
• all the applicable variants of the invention may be implemented, in whole or in part, by adapting them to the nonwoven or to the type of complex reinforcement used.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Road Paving Structures (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Bridges Or Land Bridges (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications After (1)

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• 1997
  • 1997-08-25 FR FR9710735A patent/FR2767543B1/fr not_active Expired - Fee Related
• 1998
  • 1998-08-20 DE DE69827398T patent/DE69827398D1/de not_active Expired - Lifetime
  • 1998-08-20 AT AT98942757T patent/ATE281564T1/de not_active IP Right Cessation
  • 1998-08-20 BR BR9811358-5A patent/BR9811358A/pt not_active Application Discontinuation
  • 1998-08-20 CA CA002301741A patent/CA2301741A1/fr not_active Abandoned
  • 1998-08-20 AU AU90773/98A patent/AU748483B2/en not_active Ceased
  • 1998-08-20 EP EP98942757A patent/EP1012395B1/de not_active Expired - Lifetime
  • 1998-08-20 WO PCT/FR1998/001824 patent/WO1999010600A1/fr not_active Ceased
  • 1998-08-20 PL PL98339007A patent/PL339007A1/xx unknown
  • 1998-08-21 EP EP98942766A patent/EP1009879A1/de not_active Withdrawn
  • 1998-08-21 AU AU90780/98A patent/AU9078098A/en not_active Abandoned
  • 1998-08-21 WO PCT/FR1998/001833 patent/WO1999010601A1/fr not_active Ceased

Non-Patent Citations (1)

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