FR2486558A1 - Antiskid road surface - comprises hardenable mixt. of polymer and sand evenly distributed over road surface - Google Patents

Abstract

An anti-skid surface comprising a hardenable mixture of a polymerisable material and sand is applied to e.g. a road surface by projecting fragments of the mixture in an evenly distributed manner over the surface. The hardenable mixture is pref. made up of an epoxide resin of bisphenol A diglycidyl ether and a hardener containing a blend of diethylene triamine and bisphenol A. The material is pref. applied from a reservoir having holes in its floor which travels on wheels over the road surface.

Description

Method and device for producing a non-slip coating on a support. And coating thus obtained.

 The present invention relates to a process for producing an anti-wicking coating on a support having a free surface, of the type according to which a curable mixture comprising a polymerizable material in the non-polymerized state and of the sand, and this mixture is allowed to harden on the support.

 The invention also relates to a device for implementing this method.

 Usually, an anti-slip coating is produced, for example on a roadway, by first applying, on the roadway, a film about 2mm thick, of a binder in the form of a polymerizable resin added with sand, then spreads gravel on this film before the binder hardens.

These gravel being typically of particle size "6-10 mm ^ ', that is to say gravel passing through a sieve whose square meshes are 10 mm side but not passing through a sieve whose square meshes are 6 mm side.

 The essential disadvantage of such a non-slip coating is that it will crack as soon as the binder hardens, this cracking being mainly due to the phenomenon of withdrawal of the binder.

 This is why an object of the present invention is to propose a new process making it possible to obtain a non-slip coating preventing cracking by the shrinkage occurring at the time of the polymerization of the binder.

 Another object of the present invention is to provide a simpler and less expensive method than the aforementioned known method.

For these effects, the method according to the invention is characterized in that the mixture is spread on the support by projecting, on the latter, in a distributed manner, fragments of the mixture
Thus, rather than applying a uniform and continuous binder film on the pavement and then graveling on it, the desired macrorugosity is created by spraying the binder (sand + resin) possibly loaded with aggregates of small particle size, for example 2 - 4 mm or 4 - 6 mm, on the support so that it sticks to it, forming non-contiguous asperities which will play the role of "aggregates" after polymerization of the product. "2-4 mm" of grain size means: which crosses a sieve whose square mailies are 4 mm wide, but which does not pass through a sieve whose meshes are 2 mm wide.

 By this means, on the one hand, the mass effect of a continuous binder film is eliminated, which solves the problem of cracking of the coating by polymerization shrinkage, on the other hand, a large part of resin while obtaining a particularly rough surface, suitable for drainage of water under the tires and very poorly polishable, and bypassing the gravel operation of the coating.

 In addition, the essentially discontinuous coating obtained by the process of the invention is perfectly suitable for particularly flexible supports, such as certain works with a metal apron, the sealing function possibly being able then to be ensured by a veil of conventional hydrocarbon binder which would come protect the uncoated support parts.

 Advantageously, said fragments are projected by letting them fall freely onto said free surface of the support.

 According to one example, the polymerizable material comprises an epoxy resin of the diglycidyl other family of bisphenol A, added with a hardener comprising a mixture of diethylene triamine and bisphenol A.

 According to a preferred embodiment, the sand comprises a crushed natural sand such as Nemours sand, with a particle size between 0.1 and 0.3 mm.

 Typically, the weight content of sand is two to four times that of polymerizable material.

The device for producing an anti-slip coating on a support, according to the invention, is characterized in that it comprises:
- a chassis fitted with wheels, intended to roll on the support,
a tank intended to contain a substantially liquid mixture comprising a polymerizable medium and sand, this tank having a bottom wall provided with holes, and
- Means for closing and opening said holes.

By "substantially liquid" is meant: "of a viscosity such that the liquid can flow by gravity".

 Advantageously, the closure means comprise a perforated plate applied to one face of the bottom wall, this plate being mounted on the tank so as to be able to move relative to the bottom wall at least along an axis, motor means being provided to move the shutter plate relative to the bottom wall.

 Advantageously, the shutter plate is applied to the outer face of the bottom wall of the tank.

 Advantageously, the drive means are means applying to said shutter plate a back-and-forth movement.

 Advantageously, the tank is mounted & height adjustable on the chassis.

The characteristics and advantages of the invention will be better understood on reading the following description of an embodiment of the invention, description made with reference to the accompanying drawings in which
- Figure 1 is an elevational view in vertical section along fI of Figure 2, of a device for producing a non-slip coating, according to one embodiment of the invention
- Figure ia is a partial view of the cross section along AA of Figure 1
- Figure 2 is a top view of Figure I; and
- Figure 3 shows the appearance of an anti-slip coating, according to one embodiment of the invention.

EXAMPLE OF CURABLE MIXTURE
The polymerizable material consists of an epoxy resin of the DGEBA type (diglydicyl ether of bisphenol A) modified by a reactive diluent such as ortho cresol glycidyl ether in order to lower its viscosity, and a hardener which is a mixture of diethy lene triamine (DETA) and bisphenol 1.

 The sand used is a natural crushed sand (Nemours sand) totally siliceous with a tight particle size of 0.1 - 0.3 mm, very clean and dry.

Composition of the mixture (by weight)

<tb> - <SEP> resin <SEP>: <SEP> (80 <SEP>%)
<tb><SEP> 25 <SEP>%
<tb> - <SEP> hardener <SEP>: <SEP> (20 <SEP>%)
<tb>
- sand 75%
- binder density: 2
This binder (polymerizable material + sand) can optionally be loaded with aggregates in order to give it a larger mineral skeleton, while saving a portion of the product. The viscosity of the mixture can be modified by modulating the proportion of sand.

The different components are taken and homo
genitized at room temperature. The duration of polymdri-
sation can be estimated at 4 hours for a temperature
ambient temperature of 250C.

EXAMPLE OF A DEVICE FOR THE APPLICATION OF
THIS MIXTURE ON A MEDIUM
Figures 1 and 2 show a dispo
sitive for the realization of a non-slip coating
on a support.

This device includes
- a chassis 1 fitted with wheels 2, intended for & BR <
roll on a support such as a floor 3,
- a hopper-shaped reservoir 4 intended
to contain a substantially liquid mixture comprising
polymerizable material and sand, this tank
having a bottom wall 4a provided with holes 5, and
- means for closing and opening the said
holes.

According to the example shown, these means
shutter includes a perforated plate 6 apps
quée on a face 4b of the bottom wall 4a, this
plate 6 being mounted on the reservoir 4 so
to be able to move in translation relative to the
bottom wall 4a in a rectilinear direction (double arrow f) parallel to the longitudinal axis 7 of the
bottom 4a of tank 4, motor means being
provided for moving the shutter plate 6 relative to
to the bottom wall 4a.

The bottom wall 4a and the shutter plate
6 are flat and this last plate is applied
on the outer face 4b of the bottom wall 4a of the
tank 4.

The driving means are means applying
to said shutter plate 6 a back and forth movement
comes successively to close and open the holes 5, each hole 6a of the shutter plate 6 corresponding to a hole 5 in the bottom 4a, the set of holes 6a being superimposable & the set of holes 5. The motor means comprise an electric motor B with a vertical axis, the casing of which is fixed to the reservoir 4 by a bracket 9. The output shaft 8a of the motor 8 carries, in rotationally integral manner, a crank 10. A connecting rod is articulated, on the one hand, at 12 on one end of the shutter plate 6 and, on the other hand, eccentrically, at 13, on the crank 10 (Figure 1). The plate 6 is guided on the lower face 4b of the bottom 4a by means of a slide formed by two angle elements 14 welded, by their upper wing 14a on the base of an adjacent side wall 4c of the tank 4 (FIG. 1a) .

 The reservoir 4 is mounted on the ch ssis 1 by means of elements of adjustable height 15.

 When the product to be applied is contained in the hopper 4, fragments - or bundles of this product flow by gravity onto the free surface 3a of the support 3 when the openings 5, 6a are in coincidence, and are pressed - or s' crush - on the ground 3 with a speed depending on the height of fall of said fragments.

 When the orifices 5 are closed, the plate 6 forming a knife cuts the binder drips coming from these orifices 5 and stops the flow of the mixture.

 It should be noted that the vibrations resulting from the movement of the obturator plate 6 facilitate the flow of the product, therefore the supply of the device.

 FIG. 3 shows the appearance of a coating obtained with a curable mixture according to the example given above, loaded with aggregates of 2-4 mm particle size, the mixture being spread on the ground at a rate of 2 to 6 kg per m2.

Thus, the implementation of the method according to the invention requires a particular device but it eliminates the "graveling" operation. This simplification is accompanied by significant savings
(cost of transport over long distances small quantities of specially prepared aggregates). The possibility of loading the binder with aggregates to strengthen the mineral skeleton of the roughness also contributes to reducing the consumption of resin.

 This process is applied cold on a dry floor. The importance of mineral fillers should make the binder age much slower than a binder - pitch or epoxy bitumen.

The method according to the invention makes it possible to obtain a much greater roughness which can however be reduced by varying the dimension of the roughness, which should result in an appreciable saving in the quantities of materials used,
In addition, the aggregates have good resistance to polishing since the presence of grains of sand + resin ensures self-regeneration of the microroughness.

 Thus, the simultaneous conservation of microroughness and macroroughness should ensure very good conservation of the anti-slip characteristics under real traffic.

The bonding power of the product must allow the treatment of all black spots or particular sites, whatever the nature of the support.
(Breton cement, bituminous mix, metal slabs),
The possibility of tinting the product offers interesting perspectives (optical effect) for example, in slowdown zones, by reinforcing traditional vertical signaling.

Of course, variants can be made to the method and to the device described above without departing from the scope of the present invention. In particular, the binder used can be other than that specified in the example given above. This binder can be another epoxy resin or else a resin belonging to another sheet, for example a polyurethane resin. Likewise, the sand of
Nemours can be replaced by other siliceous sands with a possibly larger particle size. The proportion resin / sand of the mixture can be different from the value 25% / 75% given above by way of example.

Claims (8)

1. Method for producing an anti-slip coating on a support having a free surface, of the type according to which a curable mixture comprising a polymerizable material in the non-polymerized state and sand is spread over the free surface of the support, and is left harden this mixture on the support, characterized in that the mixture is spread on the support by projecting onto the latter, in a distributed manner, fragments of the mixture. 2. Method according to claim 1, characterized in that said fragments are projected by dropping them freely on said free surface of the support. 3. Method according to one of claims 1 and 2, characterized ink that k mixture further comprises aggregates of particle size between 6 mm and 1 mm and, preferably, between 4 mm and 2 mm. 4. Method according to one of claims 1 to 3, characterized in that the polymerizable material comprises an epoxy resin of the diglycidyl ether family of bisphenol A, added with a hardener comprising a mixture of diethylene triamine and bisphenol A. 5. Method according to one of claims 1 4, characterized in that the sand comprises a crushed natural sand such as Nemours sand, of gra nulometry between 0.1 and 0.3 mm. 6. Method according to one of claims 1 to 5, characterized in that the content by weight of sand is two to four times that of polymerizable material. 7. Non-slip coating obtained by the method according to one of the preceding claims.  Device for producing a non-slip coating on a support, characterized in that it comprises  - a chassis (1) provided with wheels (2), intended to roll on the support (3),  a tank (4) intended to contain a substantially liquid mixture comprising a polymerizable material and sand, this tank having a bottom wall (4a) provided with holes (5), and  - Means for closing and opening said holes (5) 9. Device according to claim 8 characterized in that the closing means comprise an openwork plate (6) applied to one face (4b) of the bottom wall (4air this plate (6) being mounted (14) on the tank t4) so as to be able to move relative to the bottom wall (4a) at least in one direction (7), motor means (8 to 13) being provided for move the shutter plate (6) relative to the bottom wall (4a). 10. Device according to claim 9, characterized in that the shutter plate (6) is applied to the outer face (4b) of the bottom wall (4a) of the tank (4).