FR2608184A1 - Supporting element comprising a cellular layer and methods for making a temporary road surface using the said supporting element - Google Patents

Abstract

The present invention relates to a supporting element intended to enable unstable ground to be travelled over by land-based or air-based machines. The supporting elements according to the present invention consist of a cellular layer 1 on which a covering 2 is adhesively bonded. The covering 2 consists of a basic material 6 such as stone chips in an organic coating substance 7. The upper surface of the cellular layer 1 is covered with a sheet of fibres 4. The lower surface of the cellular layer 1 is preferably left open in order to improve anchoring in sandy or muddy ground. These supporting elements make it possible, in particular, to form plates for digging vehicles out of sand or out of mud, or landing strips. The present invention also relates to the formation of a temporary road surface by means of the said supporting elements.

Description

 The present invention relates to a support element intended to make practicable, by land, air vehicles or .. amD'iE: ies, unstable soils.

 The invention also relates to a procedure for making a temporary pavement.

 The movement of wheeled or tracked vehicles on unstable ground often leads to problems of entanglement or silting up, when the tire or track pressure exceeds a threshold admissible by the terrain.

 To release the vehicle, a number of techniques are generally known which consist in practicing using a shovel a light ramp in front of the silted up wheels, and in depositing semi-rigid elements of the branch type at the bottom.

 Also known are perforated metal plates called "PSP", in the form of rigid strips a few tens of centimeters wide and about one meter long. These plates can be deposited on soft, muddy or sandy soil, so to prevent the clogging of vehicles. They can also constitute landing areas, in particular for helicopters, or temporary pavements. The disadvantage of these plates is that their handling is not very easy. Their weight is indeed quite significant and the installation generally requires more than one person. Furthermore, the passage of heavy vehicles causes deformations making it difficult to store and set up for a new use.

 The present invention overcomes these drawbacks, and in particular aims to achieve a light and effective support element, that is to say which has good resistance to the pressures generated by the passage of vehicles, whatever the nature of the terrain on which it is deposited. The present invention also relates to temporary landing areas.

 The retaining elements according to the present invention consist of a coating composed of a base material in the form of granules coated in an organic substance, adhering to a cellular layer with cells substantially perpendicular to the coating.

 The honeycomb layer is produced by extrusion from a thermoplastic material, using the devices and methods described in French patents 80 23188 and 85 09554 of the applicant. The alveolar layer consists of a juxtaposition of alveoli with a diameter of a few millimeters to a few tens of millimeters.

Alveoli of any shape, and preferably hexagonal, are made of rot-proof and non-brittle plastic material. The thickness of the alveolar layer is between approximately 1 centimeter and a few tens of centimeters. It can be coated on the upper face, or on both sides, with a sheet of woven or non-woven fibers of polyprnpy ene, polyester, cutoneaute material. A coating is deposited on the upper face of the cellular layer. This coating consists of a mineral base material, having a good quality of hardness and adhesion, and coated with an organic substance. Said base material may consist of gravel, with a particle size less than 15 mm and preferably greater than 5 mm. The base material is coated in an organic substance forming a substrate having a certain elasticity. This organic substance is chosen from the vinyl polymer type, and in particular polyvinyl chloride or acetochloride.
of vinyl, - plastic material of the polyurethane type, - polymer of the epoxy type, - synthetic or natural rubber, - synthetic or natural bitumen, - petroleum oil, asphalt, tar, pitch, - coal oil comprising mineral fillers of small particle size , - elastomer or plastomer.

This coating has a thickness of a few millimeters. I1 is secured to the upper face of the honeycomb layer by any known means, and in particular by cold bonding using an epoxy adhesive.

 The cells of the cellular layer are oriented substantially vertically with respect to the plane formed by the coating.

 The structure thus produced has great resistance to the pressure exerted on its upper face. Due to the qualities of flexibility and resistance of the coating, the forces exerted on the upper face of the support element are well distributed over several cells of the cellular layer and exclude localized crushing of the latter.

Bonding is facilitated when the upper surface of the cellular layer is coated with a sheet of fibers. The support element produced according to a first variant is in the form of a rectangular plate. The dimensions of this plate are chosen so as to have a sufficient surface area for a reasonable weight, so as to allow installation by a single man. The width will preferably be greater than the width of the largest of the wheels or tracks of the machines intended to circulate on said support element. Advantageously, these plates will have a width of between 50 cm and 1.50 m, and a length of 1 to 2 m
According to an advantageous embodiment, the retaining elements comprise lateral anchoring points. These lateral anchoring points can be formed by virtue of a particular section of the retaining element making it possible to fit them in the manner 'a puzzle". Two supporting elements can be connected by interlocking, by sliding one element in the other along their complementary edges. The edges of the support elements thus produced have complementary recesses and "ears" for the edges capable of fitting together. These "ears" are of sufficient size to avoid breakage in the event of deformation resulting from pressure exerted on the upper face.

 According to another variant, the retaining element is produced in the form of a mat, possibly rollable around a support when it is not in use. According to this variant, the alveolar layer comprises a series of pernendicular interruptions in the direction of the hoarseness. allowing folding without breaking of the retaining element. These i nte. - Straight rectifications are regularly spaced and are made ar -o a ~ e cold of cellular plates spaced a few millimeters between them.

on a coating of the aforementioned type. The taois thus formed has a gor of a few tens of centimeters to 1 meter, or even more, and a length which can reach several tens of meters. This mat can be rolled up for transport around a drum.

 The retaining element, whether it is in the form of a plate or a mat, constitutes a means of sand removal or settling which is easy to implement, and the installation of which can be carried out without difficulty by a single man. Because of its lightness, its transport poses no problems.

 For this application of sanding plate or mists.

the lower face of the honeycomb layer is not coated with a sheet of fibers, so as to improve the anchoring of the support element in the unstable ground.

 These support elements can also be used to form a temporary landing area, in particular for helicopters. The retaining elements according to the invention allow a very rapid installation of a large arranged surface, whatever the nature of the ground supporting them, in particular in the embodiment in the form of a carpet, preferably of the type with honeycomb layer. coated on both sides with a sheet of woven or non-woven fibers.

 The present invention also relates to a process for making a temporary pavement, consisting in depositing on an unfinished ground at least one retaining element according to the invention.

 Other advantages and embodiments will emerge more clearly from the description of a few examples of implementation of the present invention which are illustrated by the following drawings.

 Figure 1 shows a sectional view of a support element according to the invention produced in the form of a mat.

 FIG. 2 represents a view of a selo 1 invention support element comprising lateral anchoring points.

 The support element produced in the form of a mat, as shown in Figure 1, consists of a cellular layer (1) and a coating (2). The honeycomb layer (1) consists of a juxtaposition of hollow cells (3) made of a non-putrable thermoplastic material. The cells (3) are arranged substantially perpendicular to the plane formed by the coating (2). The upper face of the honeycomb layer is coated with a sheet of fibers (4). Depending on the type of application of the retaining element according to the invention. the underside of the honeycomb layer is also coated with a sheet of fibers (5).

For use on sandy soil. muddy or muddy, the honeycomb layer (1) is not coated with a nonwoven web on its lower surface. The lower ends of the cells (3) thus remain open and form elements for anchoring the support element in unstable soil. The coating (2) consists of a base material (5) embedded in an organic substance (7). The base material, of the gravel type, is flush with the upper surface of the covering (2) so as to improve the grip of the vehicles on said support elements. The coating (2) is bonded to the cellular layer (1) preferably using cold glue.

 In the particular embodiment in the form of a carpet, the honeycomb layer (1) has interruptions (8) facilitating the winding of said carpet around a cylindrical support. In this case, the winding is done around the upper face. These interruptions (8) are spaced about ten centimeters apart, and according to a particular embodiment, this spacing increases from the start to the end of the carpet. These interruptions (8) are formed either by grooving the honeycomb layer, or by gluing honeycomb plates (1) of fixed or variable length on the covering (2).

 According to a variant, the retaining elements comprise lateral edges (9) and (10) cut according to a particular profile, so as to present lateral anchoring points (11), (12). The support elements thus produced can fit into each other in the manner of a "puzzle", so as to form a continuous support surface. These lateral anchoring points can be produced both on the support elements in the form of a carpet and on the elements in the form of plates.

 According to an example of application, the support element constitutes a beach mat for exiting vehicles from a landing boat (in English heaching) or a raceway for exiting the bank of land or amphibious vehicles.

 These examples are given without implied limitation, and all the variants fall within the scope of the present invention.

Claims (15)

RET.N'DICATI0NS  1) Support element intended to make it practicable by land, air or amphibious vehicles, unstable soil, characterized in that it consists of a coating (2) composed of a base material (6) in the form of granules coated with a coating substance (7), said coating (2) adhering to a cellular layer (1), the axis of the cells being substantially perpendicular to said coating.  2) Support element according to claim 1, characterized in that the upper face of the cellular layer (1) is coated with at least one layer of fibers (4)  3) Support element according to claim 2, characterized in that the coating O) is bonded using a cold glue on the upper surface of the cellular layer (1).  4) Support element according to any one of claims 1 to 3, characterized in that the two faces of the alveolar layer (1) are coated with a sheet of (4), (5).  5) Support element according to any one of claims 1 to 4, characterized in that the thickness of the cellular layer (1) is between 1 and 10 cm.  6) Support element according to any one of claims 1 to 5, characterized in that said base material (6) is coated in a substance chosen from the group of organic substances constituted by elastomers and plastomers.  7) Support element according to any one of claims 1 to 6, characterized in that the base material (6) consists of mineral fillers with particle size less than 15 mm.  8) Support element according to any one of claims 1 to 6, characterized in that it constitutes a rectangular plate.  9) Support element according to claim 7, characterized in that it comprises lateral anchoring points (11), (12).  10) Support element according to any one of claims 1 to 6, characterized in that it constitutes a mat  11) Support element according to any one of claims 1 to 10, characterized in that it constitutes desensablsge means.  12) Support element according to any one of the claims  1 to 10, characterized in that it constitutes a temporary landing area.  13) Support element according to any one of claims 1 to 10, characterized in that it constitutes a beach mat for exiting vehicles from a landing boat.  14) Support element according to any one of claims 1 to 10, characterized in that it constitutes a raceway for exit from the banks of land or amphibious vehicles.  15) Method for making a temporary pavement, characterized in that at least one supporting element according to is provided on an unfinished ground. any one of claims 1 to 12.