FIELD OF THE INVENTION

This invention refers to a pavement for sliding sports, such as blade-skating. More specifically, the invention provides for a synthetic pavement, i.e. a pavement made of materials other than icie and therefore usable without resorting to cryogenic equipment. PRIOR ART

Pavements for blade-skating made of materials different from ice (DE 3-4 -45 976, PCT/EP 91/00006) have been developed in order to reduce the high investment and maintenance costs of ice pavements formed and mantained by means of cryogenic plants. Once worn out by use, the surface, or skating mantle, of the above mentioned pavements made of such materials, is restored by simply melting out the worn out layer or by means of a backfill of liquid material, eliminating in this way any wear trace. Besides, this restoring can be performed for an almost unlimited number of times.

In order to form pavements having optimal characteristics with the materials described in the above mentioned patent applications, specific applying techniques had to be developed. In particular, it was necessary to prevent a possible and progressive detachement of the skating mantle from the substratum on which it had to be applied, as such detachment would result in turn in the destruction of the pavement. This possibility should be taken into account inasmuch it may ensue

either from seasonal changes in temperature (it should be remembered that pavements may also be built outdoors) or as a consequence of repeated thermal cycles due to normal repair of the skating mantle. A special technology has now been found for the formation of said pavements, which permits to overcome the above mentioned drawbacks, and which, besides, is obtainable to very low costs. SUMMARY OF THE INVENTION

It is an object of the present invention to obtain a pavement for sliding sports, such as blade-skating, said pavement comprising: (i) a top paraffinic layer; (ii) an intermediate layer, compatible in the melted state with said top layer; (iii) a rigid substratum, characterized by surface discontinuities, either due to the very nature of the substratum or artificially obtained when producing the substratum, for instance by partially incorporating in it foreign materials or else by producing in the substratum cavities which open outwards, said discontinuities constituting an anchoring between the intermediate layer and the substratum when the former is poured on the latter.

A further object of the invention is the process for forming said pavement.

Other objects of this invention are made clear in the following description.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention , the top layer comprises a mixture of linear , branched or cyclic hydrocarbons , and polymers and

copolymers of ethylene, propylene, butylene and mixtures thereof, said mixtures having a melting temperature ranging from 30 to 130 C. The products described as LMM in the patent application PCT/EP 91/00006 are particularly preferred. The intermediate layer is made up by a material compatible in the melted state with the top layer and apt to absorb, at least partially, by elastic and/or plastic deformation, the tensions due to shrinking from its solidification temperature to the temperature of utilization, once said top layer is rigidly anchored to the substratum.

Suitable materials to form the intermediate layer may be constituted by a mixture of the material making up the top layer and plasticizing and/or elasticizing additives added in such a quantity as to reproduce the above conditions. For instance, the following can be advantageously used as additives: rosin and colophony derivatives, ethylene/vinyl acetate copolymers and other additives known to those skilled in the art. Additions may be such as to produce a final mixture comprising at least 5% b.w. of additives. The intermediate layer may also contain fire-proof charges known to the art, such as, for instance, mixtures of chloroparaffin and antimony oxide.

Particularly preferred for the intermediate layer are the products described in the above mentioned PCT application and identified as LTTP.

The thickness of the layer is not a critical factor and depends on the construction requirements of the pavement. In general, the thickness of the intermediate layer and the top layer will be of 3~-L0 mm and 3~6 mm respectively. The substratum may be constituted by any rigid material. In particular, it may be for instance cement, bricks, asphalt, wood, laminated plastic, or even glass, or other materials applicable in the semifluid (or semisolid) state and hardening thereafter, during the setting stage. Anchorings are constituted by discontinuities of the substratum surface which is in contact with the intermediate layer, meaning by discontinuities those cavities and/or bulges existing on such surface which respectively incorporate portions of the material constituting the intermediate layer and/or are incorporated by the latter. Such incorporations are formed by pouring on the substratum the material of the intermediate layer.

Said cavities may be obtained artificially by creating holes, cuts, incisions, and/or profiles on the substratum surface on its formation. Or else they may be innate in the substratum in form of macroporosities, as, for instance, in foamed bricks, cement or foamed clay articles. Bulges are preferably obtained by using materials that can be partially embedded in the substratum when "the latter is still in the semiliquid state, and partially emerge from it on its solidification. Although articles of different kind may be used, they should always be capable of contrasting all of the forces arising as a consequence of the thermal contraction of the system comprising

the intermediate layer and the top layer. Such forces have not only tangential components, due to shrinking after solidification, but also vertical components: the thicker the materials overlying the anchoring, the stronger the vertical components. In particular, the following are preferred because of their extremely low cost: nets of any type, spirals, metal scraps.

The formation of the pavement according to this invention may be carried out by applying in succession the intermediate layer and the top layer by direct pouring on a single pouring bed, with undeniable cost advantages.

The pavements formed according to this invention have never given rise to detachment of skating material, not even outdoors in severe weather conditions. Besides, their production costs are decidedly low, and their installation is easy. As well as for blade-skating, the pavements described may be used for any other sports for which an adequate sliding surface is required, such as, for instance, bobsledding, sledding, skiing.

The following examples are given to better define the invention and should not be regarded as a limitation of same. Top layer composition a) paraffin wax with a penetration index of 25 (measured at 20°C with needle penetrometer, MEM method) , saponification 0, iodine number 0; b) microcrystalline polyethylene wax, with melting point ranging between 110 and 120°C; in the proportion of: 702 b.w. of a) and "$0% b.w. of b) .

Intermediate layer composition a) paraffin wax as above; c) EVA at 30% of vinyl acetate; in the proportion of: 65 b.w. of a) and 35 b.w. of c) . Type of anchoring

I) BULGE-TYPE ANCHORING, obtained through the following process.

The substratum (in this case cement) has been poured in the semiliquid stage, and the anchoring, constituted by a metal spiral net, has been half-embedded in it. II) CAVITY-TYPE ANCHORING, constituted by a vibrated cement artifact having -400 holes, with a 12 mm diameter and a 10 mm depth per m ² . Ill) BULGE/CAVITY MIXED-TYPE ANCHORING, constituted by reinforced foamed clay artifacts. Application process The intermediate layer has been poured in the fluid state and at a temperature of lδθ ^° C on each of the three substrata, in the proportion of 10 kg/m ² .

After cooling, the top layer has been poured in the same way at a temperature of l8θ ^° C in the proportion of 5 kg/m ² .

Pavements according to this invention have not given rise to detachments, neither of the top layer nor of the substratum, not even when, exposed to water and freezing.