MX2011004784A - Recycling of road surfaces. - Google Patents

Abstract

The invention relates to a method for producing roads, paths and other surfaces for traffic. According to said method, a mixture containing crushed road surface material, mineral material and/or glass, a polymer reaction mixture and optionally other additives is produced, is applied to a foundation and is hardened. The invention also relates to roads, paths and other surfaces for traffic that are obtained according to a method of this type.

Description

RECYCLING OF PAVEMENTS Description The present invention relates to a process for the manufacture of streets, roads and other traffic surfaces, in which a mixture containing crushed pavement, mineral material and / or glass, a polymeric reaction mixture, as well as, possibly, other materials is prepared. additives, it is applied on a base material and hardens. In addition, the present invention relates to streets, roads and other transit surfaces, which can be obtained by means of said procedures.

Other embodiments of the present invention are to be taken from the claims, the description and the examples. It is understood that the characteristics of the object according to the invention previously mentioned and to be explained below can be used not only in the combination indicated in each case, but also in other combinations, without departing from the scope of the invention.

The streets are mostly made of asphalt. For this, a mineral mixture is applied, mostly with bitumen as binder, possibly in several layers on the base. In addition, pavements with a plastic as a binder are also known as described, for example, in DE 19605990 and DE 19651749.

Usually, bitumen-based streets should be renewed according to quality and load after approximately 12 to 18 years, in the case of open-pore cover layers, even after 6 to 7 years. For this, the old asphalt is partially or totally removed. The material removed can possibly be reused in small quantities with the same particle size distribution, preferably up to 15% by weight. For this, the material must be transported to an asphalt mixing plant and mixed there at temperatures of approximately 180 ° C with fresh bitumen, as well as mineral material. Then the asphalt thus manufactured is transported again from the plant Asphalt mixer to the place of assembly. By means of this procedure the environment is recharged, especially by means of the necessary vehicular traffic, as well as the great energy consumption in the asphalt mixing plant. Beyond this, the asphalt, which can not be reused and whose binder still contains a tar ratio, must be disposed of as special waste due to the toxicity of the tar.

It was an object of the present invention to provide a method for the manufacture of streets, roads and other traffic surfaces that load less the environment.

The object according to the invention is solved by means of a process for the manufacture of streets, roads and other transit surfaces, in which a mixture containing crushed pavement, mineral material and / or glass, a polymeric reaction mixture and optionally other additives, it is applied on a base material and hardens.

Usually, streets, roads and other traffic surfaces are structured with several layers. They have at least one cover layer bonded to the surface, as well as eventually other deeper layers bound and unbound. Most of the time, in the case of the deeper bound layers, these are the so-called load-bearing layers and, in the case of the deeper, unbound layers, these are base layers formed by gravel and coarse sand. Binders, plastics or bitumen are usually used as binders for bonded cover layers and carrier layers.

The process according to the invention relates in this case to the preparation of bonded layers. In this case, it can be both carrier layers and also cover layers. The carrier layers and the cover layers are distinguished mainly by the average diameters of the mineral material used. Preferably, the method according to the invention relates to the preparation of cover layers. Any material, such as sand, earth, mud, concrete, stone, can be used as the base material. Base materials, base layers and / or carrier layers are preferred.

Crushed pavement means both crushed or split cover layers, as well as crushed or broken backing layers and crushed gravel or coarse sand layers. Preferably, in the case of the crushed pavement, these are crushed bonded layers, especially crushed cover layers. The binder for the bonded bonded layers is, preferably in this case, a binder based on polymers or based on bitumen, especially on the basis of bitumen. By means of this variant of particular preference both the thermoplastic or viscoelastic properties of the bitumen as well as the high temperature properties of the polymeric binder are applied. The granulometric distribution of the crushed pavement can be regulated in this way in a known manner by adapting the crushing conditions or separating unwanted grain sizes. Also the cover layers based on cast asphalt can be used according to the invention as a basis for crushed pavement.

As a mineral material, all known mineral material can be used in this case. In this case, it is, for example, sand or crushed stone, called split material, where the sand has a preponderantly round surface and has edges of split material and breaking surfaces. A material that is predominantly composed of split material is particularly preferably used as the mineral material.

As glass, crushed or split glass is preferably used. In this case, the breaking of the glass is preferably colored, for example, to be able to apply markings. The glass can be used in this case together with the mineral material or instead of the mineral material. Preferably, only mineral material and no glass is used.

With particular preference, the mixture of crushed pavement and mineral material and / or glass has a granulometry as indicated in the provisions of the construction of bituminous streets and depending on the purpose of application, for example, for load-bearing layers and cover layers , as asphalt mixed with mastix or asphalt with drainage. The regulation of the granulometry can be done by regulating the sizes of the grains of the pavement using mineral material with a certain granulometry or both. In this case, the crushed pavement and the mineral material can be mixed in any proportion of mixture. Preferably, the proportion of ground floor is preferably less than 95% by weight, with particular preference between 5 and 80% by weight and especially between 10 and 70% by weight, based on the total weight of the floor. mixture composed of crushed pavement and mineral material.

By polymeric reaction mixture is meant, in this case, a mixture that is able to react with a polymer. They comprise mixtures containing molecules that can react, for example, by means of chain growth reactions such as radical polymerization or ion polymerization to the polymer, for example, unsaturated compounds, molecules that are able to participate in polycondensation reactions as polyalcohols, or molecules that are able to participate in polyaddition reactions such as polyols and polyisocyanates or as epoxides. The polymer reaction mixtures according to the invention are preferably liquid at 40 ° C.

Preferably, in the case of the polymer reaction mixture, it is a mixture for preparing an epoxy resin or a polyurethane. In particular, it is a mixture for preparing a polyurethane, a polyurethane reaction mixture. In this case, the polymer reaction mixture preferably contains essentially no solvent.

Preferably, the polymers obtained from a polymeric reaction mixture are compact, that is to say, they contain practically no pores. With respect to cell polymers, compact polymers are characterized by greater mechanical stability. Bubbles can appear inside the polymer and are mostly not critical. However, they should be minimized as much as possible. In addition, it is preferable that the polymers obtained be hydrophobic. For this, a degradation of the synthetic materials by means of water is repressed.

Preferably, the polymeric polymer reaction mixtures have compounds to improve adhesion with the recycled material, as well as the mineral material. In this case, it is, for example, hydroxy- or alkoxyamino silane compounds of the general formula (I) in which X is, independently of each other, OH, CH3, O [CH2] pCH3; Y is [CH2], [(CH2) rNH (CH2) s] b, [(CH2) rNH (CH2) s NH (CH2) z] b; R, R 'are H, [CH2] tCH3; t is 0 - 10 n is 1 - 3; P is 0-5; m is 4 - n; r, s, b, z are, independently of each other, 1 -10.

In general, the alkylaminosilane compound (I) is a compound of trihydroxy-, dialkoxy- or trialkoxyminosilane. Preferred alkoxy radicals X are methoxy and ethoxy. The amino group must be an amino group reactive with isocyanate groups, i.e., a primary or secondary amino group. Preferred alkyl radicals R are hydrogen, methyl and ethyl.

In the case of the alkylaminosilane compound (I), it is preferably a trihydroxyminosilane compound or a trialkoxyaminosilane compound, wherein in formula (I) X = OH or O [CH2] pCH3 and p = 0.1.

Furthermore, more preferably, in the case of the alkoxyminosilane compound (I) it is an alkoxy diaminosilane compound, wherein in the formula (I) Y = [CH2] rNH [CH2] syr, s are the same or different, 1, 2. Examples are [CH2] 3 NH [CH2] 2, [CH2] 2 NH [CH2] 2, [CH2] NH [CH2], [CH2] 3 NH [CH2] 3, [CH2CH (CH3) CH2] NH [CH2] 2 and [CH2] 2NH [CH2] 3.

In particular, in the case of the alkoxyminosilane compound (I), it is a trialkoxy diaminosilane compound, wherein in the formula (I) X = O [CH2] pCH3 with p = 0, 1 and Y = [CH2] rNH [CH2] s with r, s, equal or different, = 1, 2.

Particularly preferred alkoxyminosilane compounds (I) are 3-triethoxysilylpropylamine, N- (3-trihydroxysilylpropyl) ethylenediamine, N- (3-trifluoromethylpropyl) ethylenediamine and N- (3-methyldimethoxymethylsilyl-2-) methylpropyl) ethylenediamine.

In this case, the compounds for improving adhesion are generally contained in the polymer reaction mixture in a concentration of 0.01 to 10% by weight, preferably 0.1 to 1% by weight, based on the total weight of the polymer. the polymer reaction mixture. In this case, the compound for improving the adhesion may also have reacted in the reaction mixture with other components of the polymeric reaction mixture, for example, through an OH group optionally present.

By a mixture for preparing an epoxy resin is meant within the scope of this invention mixtures containing compounds containing epoxide groups, and suitable hardeners. In this case, the mixtures are able to form epoxy resins from the compounds containing epoxide groups through these epoxide groups by polyaddition with appropriate hardeners. In this case, in the context of the invention, we speak of a mixture for preparing an epoxy resin when the production of the reaction with respect to the epoxide groups used to prepare the epoxy resin is preferably less than 90%, with special preference less than 75% and especially less than 50%.

As compounds containing epoxide groups, compounds which have at least two epoxide groups and which are liquid at room temperature are preferably used. In this case, mixtures of different compounds containing epoxide groups can also be used. Preferably, these compounds are hydrophobic or the mixtures contain at least one compound containing epoxide groups that is hydrophobic. These hydrophobic compounds are obtained, for example, by the condensation reaction of bisphenol A or bisphenol F with epichlorohydrin. These compounds can be used alone or as mixtures.

In one embodiment, mixtures of the aforementioned hydrophobic compounds, which contain epoxide groups, are used with self-emulsifying hydrophilic compounds, containing epoxide groups. In this case, these hydrophilic compounds are obtained by introducing hydrophilic groups into the main chain of the compound containing epoxide groups. These compounds and processes for their preparation are disclosed for example in JP-A-7-206982 and JP-A-7-304853.

Suitable hardeners are compounds which catalyze the homopolymerization of compounds containing epoxide groups, or which react covalently with epoxide groups or secondary hydroxyl groups such as polyamines, polyaminoamides, ketimines, carboxylic acid anhydrides and adducts of melamine, urea, phenol and formaldehyde. Preferably, ketimines, available by reaction of a compound with primary or secondary amino group, such as diethylene triamine, triethylene tetramine, propylene diamine or xylylenediamine with a carbonyl compound such as acetone, methyl ethyl ketone or isobutyl methyl ketone, aliphatic, alicyclic and aromatic compounds of polyamine and polyamide are used. Cetimines or tolerable mixtures containing ketimines are especially preferred as hardeners.

The ratio of reactive groups in the hardener to epoxide groups is preferably from 0.7: 1 to 1.5: 1, especially preferably from 1.1: 1 to 1.4: 1.

Furthermore, in the preparation of the epoxy resins, in addition to the compounds containing epoxide groups and the hardeners used, other additives such as solvents, reactive diluents, fillers and pigments can be added. These additives are known to the specialist.

By a polyurethane reaction mixture is meant a mixture of compounds with isocyanate groups and compounds with groups reactive with isocyanates, wherein the production of the reaction with respect to the isocyanate groups used to prepare the polyurethane reaction mixture is preferably less than 90%, with special preference less than 75% and especially less than 50%. In this case, the compounds with isocyanate-reactive groups comprise both high molecular weight compounds such as polyether and polyesterols as well as low molecular weight compounds such as, for example, glycerin, glycol and also water. If the production of the reaction with respect to the isocyanate group is greater than 90%, then we will speak of a polyurethane. In this case, a polyurethane reaction mixture can also contain other reaction mixtures to prepare polymers. Like other mixtures of reaction to prepare polymers can be used, for example, reaction mixtures to prepare epoxides, acrylates or polyester resins. The proportion of other reaction mixtures for preparing polymers is in this case preferably less than 50% by weight, based on the total weight of the polyurethane reaction mixture. Preferably, the polyurethane reaction mixture does not contain other reaction mixtures for preparing polymers.

In the case of the polyurethane reaction mixture it can be the so-called hardener systems with moisture. They comprise isocyanate prepolymers which form, by the addition of water or moisture, with the formation of urea groups in the first line, polyurethanes or polyureas.

Preferably, so-called two-component systems are used to prepare the polyurethane reaction mixture. For this, an isocyanate component, which contains the isocyanate compound groups, and a polyol component, which contains the compounds with isocyanate-reactive groups in such proportions of quantity are mixed, that the isocyanate index is in the range of 40 to 300. , preferably from 60 to 200 and with special preference from 80 to 150.

In this case, the isocyanate index within the scope of the present invention is understood to mean the stoichiometric ratio of isocyanate groups to isocyanate-reactive groups, multiplied by 100. By isocyanate-reactive groups, it is meant, in this case, all groups reactive with isocyanate. isocyanate contained in the reaction mixture, including chemical propellants, but not the isocyanate group itself.

The polyurethane reaction mixture is preferably obtained by mixing a) isocyanates with b) high molecular weight compounds with at least two isocyanate-reactive hydrogen atoms, as well as optionally c) chain extenders and / or crosslinking agents, d) catalysts and ) other additives. As components a) and b), as well as optionally c) to e) those compounds are used that lead to a hydrophobic polyurethane reaction mixture and to a hydrophobic polyurethane.

As isocyanates a), all liquid isocyanates at room temperature with at least two isocyanate groups can in principle be used. Preference is given to using aromatic isocyanates, especially isomers of toluylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), in particular mixtures of MDI and polyphenylenepolymethylenepolyisocyanate (Roh-MDI). The isocyanates can also be modified, for example, by incorporation of isocyanurate groups and carbodiimide groups and in particular by incorporation of urethane groups. The latter mentioned compounds are prepared by reaction of isocyanates with a lower amount of compounds with at least two active hydrogen atoms and are usually referred to as NCO prepolymers. Its NCO content is most often in the range between 2 and 32% by weight. Preferably, the isocyanates a) contain crude MDI, whereby the stability of the obtained polyurethane is increased.

In applications of the process according to the invention, in which high color stability is achieved, it is preferred to use mixtures containing aliphatic isocyanates and aromatic isocyanates. Especially aliphatic isocyanates are used with particular preference. In a special embodiment, a polyurethane top layer based on an aliphatic isocyanate can be used to protect the aromatic isocyanate-based cover layer from yellowing. In this case, the upper layer may also contain mineral material. Preferred representatives of aliphatic isocyanates are hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Due to the high volatility of the aliphatic isocyanates, they are used in most cases in the form of their reaction products, especially as biurets, allophanates, uretonimines or isocyanurates.

The isocyanates a) can also be used in the form of their prepolymers.

For this, the isocyanates a) are reacted in a known manner in excess with isocyanate-reactive compounds, for example, with the high molecular weight compounds listed in b) with at least 2 isocyanate-reactive groups, in prepolymers.

As high molecular weight compounds with at least two hydrogen atoms b) isocyanate-reactive compounds are preferably used. they present hydroxyl groups or amino groups as an isocyanate-reactive group. The amino groups as groups reactive to isocyanates lead to the formation of urea groups which, in turn, harden in a preferentially brittle polyurethane but which has a very good resistance to hydrolysis and chemicals. Preferably, polyfunctional alcohols are used as high molecular weight compounds with at least two hydrogen atoms b) isocyanate reactants, since they generally react more slowly than compounds with amino groups and thus allow for longer processing times. Beyond this, by using polyvalent alcohols with correspondingly high molecular masses, for example, greater than 1500 g / mol, a relatively elastic material is obtained.

As polyfunctional alcohols of high molecular weight, for example, polyethers or polyesters can be used. Along with the mentioned compounds, other compounds with at least two hydrogen atoms reactive to isocyanate groups can be used.

Due to their high resistance to hydrolysis, polyether alcohols are preferred as high molecular weight compounds with at least two hydrogen atoms b) isocyanate reactants. They are prepared according to conventional and known processes, mainly by accumulation of alkylene oxides in starting substances with H function. The polyether alcohols used preferably have a functionality of at least 2 and a hydroxyl number of at least 10 mg KOH / g , preferably at least 15 mg KOH / g, especially in the range from 20 to 600 mg KOH / g. Its preparation is carried out by conventional routes by reaction of at least difunctional starting materials with alkylene oxides. As starting substances, alcohols with at least two hydroxyl groups in the molecule can preferably be used, for example, propylene glycol, monoethylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol. The most functional starting materials may preferably be glycerin, trimethylolpropane, pentaerythritol, sorbitol and sucrose. As the alkylene oxides, ethylene oxide and propylene oxide, in particular propylene oxide, are preferably used.

Preferably, the reaction mixtures according to the invention contain compounds with hydrophobic groups. In this case, it is particularly preferred to use hydroxyl-functional compounds with hydrophobic groups. These hydrophobic groups have hydrocarbon groups preferably with more than 6, more preferably more than 8 and less than 200, and especially more than 10 and less than 100 carbon atoms. Compounds with hydrophobic groups can be used as a separate component or as an integral part of component a) to e) to prepare the reaction mixture. Preferably, in the case of hydroxyl-functional hydrophobic compounds, these are compounds which meet the definition of high molecular weight compounds with at least two hydrogen atoms b) reactive to isocyanates. In this case, component b) may contain hydrophobic compounds with hydroxyl functionality or preferably be composed thereof.

As the hydroxyl-functional hydrophobic compound, a fatty chemical compound with hydroxyl functionality, a fatty chemical polyol, is preferably used.

A series of fatty chemical compounds with hydroxyl functionality are known that can be used. Examples are castor oil, oils modified with hydroxyl groups such as grapeseed oil, black cumin oil, pumpkin seed oil, borage seed oil, soybean oil, wheat germ oil, rapeseed oil , sunflower oil, peanut oil, apricot kernel oil, pistachio oil, almond oil, olive oil, macadamia nut oil, avocado oil, sea buckthorn oil, sesame oil, hazelnut oil, evening primrose oil, wild rose oil, hemp oil, safflower oil, walnut oil, fatty acid esters modified with hydroxyl groups d on myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, petroselic acid, gadoleic acid, erucic acid, nervonic acid, linolic acid, linolenic acid, stearidonic acid, arachidonic acid, timnodonic acid, clupanodonic acid, cervical acid. In this case, castor oil and its reaction products are preferably used with alkylene oxides or ketone-formaldehyde resins. The last mentioned compounds are marketed, for example, by Bayer AG under the name Desmophen 1 150.

Another group preferably used of fatty chemical polyols can be obtained by ring-opening of epoxidized fatty acid esters with simultaneous reaction with alcohols and optionally subsequent transesterification reactions. The incorporation of the hydroxyl groups in oils and fats is mainly carried out by epoxidation of the double olefinic bond contained in these products, followed by the reaction of the epoxide groups formed with a mono- or polyvalent alcohol. In this case, the epoxy ring yields a hydroxyl group or, in the case of polyfunctional alcohols, a structure with a greater amount of OH groups. Since oils and fats are mostly glycerin esters, parallel reactions of transesterification also occur in the aforementioned reactions. The compounds thus obtained preferably have a molecular weight in the range between 500 and 1500 g / mol. These products are offered, for example, by the company Henkel.

In a particularly preferred embodiment of the process according to the invention, the high molecular weight compounds with at least two hydrogen atoms b) isocyanate-reactive contain at least one fatty chemical polyol and at least one aromatic hydrocarbon resin modified with phenol, in particular an indeno-coumaron resin. The polyurethane reaction mixtures d on this component b) have a hydrophobicity which in principle can even harden under water, or incorporation is possible in case of rain.

As phenol-modified aromatic hydrocarbon resins with a phenol group in the terminal position, preferably phenol-modified indene-coumaron resins are used, particularly preferably technical mixtures of aromatic hydrocarbon resins. These products are usual in shops and are offered, for example, by the company Rütgers VFT AG under the trade name of NOVARES®.

The phenol-modified aromatic hydrocarbon resins, in particular the indene-coumarona resins modified with phenol, have an OH content of between 0.5 and 5.0% by weight.

Preferably, the fatty chemical polyol and the phenol-modified aromatic hydrocarbon resin, especially the indene-coumaron resin, are used in a weight ratio of 100: 1 to 100: 50.

In the preparation of a polyurethane reaction mixture according to the invention, a chain extender c) can be used. However, in this case, the chain extender c) can be dispensed with. To modify the mechanical properties, for example, the hardness, the addition of chain extenders, crosslinking agents or possibly also mixtures thereof can be shown to be advantageous.

If chain extenders and / or crosslinkers c) of low molecular weight are used, known chain extenders can be used in the preparation of polyurethanes. They are preferably low molecular weight compounds with isocyanate-reactive groups with a molecular weight of 62 to 400 g / mol, for example, glycerin, trimethylolpropane, known derivatives of glycol, butanediol and diamines. Other possible chain extenders and / or low molecular weight crosslinkers are indicated, for example, in "Kunststoffhandbuch, Band 7, Polyurethane", Cari Hanser Verlag, 3. Auflage 1993, Kapitel 3.2 and 3.3.2.

The polyurethanes used can be prepared in principle without the presence of catalysts d). To improve hardening, catalysts d) can be used. As catalysts d), preference must be given to those which produce the longest possible reaction time. In this way, it is possible for the polyurethane reaction mixture to remain liquid for a long time. These catalysts are known to the person skilled in the art. In principle, it is possible, as described, to work absolutely without a catalyst.

Other customary components, for example, customary additives e), can be added to the polyurethane reaction mixture. They comprise, for example, usual fillers. Preferably, organic and inorganic fillers, reinforcers and customary fillers known per se are used as fillers. In particular, mention may be made, by way of example: inorganic fillers such as silicone minerals, for example, layered silicates such as antigorite, serpentine, hornblende, amphibole, chrysotile, metal oxides such as kaolin, aluminum oxides, titanium oxides and iron oxides, metal salts such as chalk, heavy spar and inorganic pigments such as cadmium sulfide, zinc sulphide, as well as glass. They are used with preference kaolin (China Clay), aluminum silicate and coprecipitates of barium sulfate and aluminum silicate, as well as natural and synthetic fibrous minerals such as wollastonite, metal fibers and especially glass of different length that can eventually be glued . Suitable organic fillers are, for example: soot, melamine, rosin, cyclopentadienyl resins and graft polymers, as well as cellulose fibers, polyamide fibers, polyacrylonitrile, polyurethane, polyester based on aromatic dicarboxylic acid esters and / or aliphatic and especially carbon fibers.

If the aforementioned inorganic fillers are used as additives e), they preferably have another mineral composition than the mineral material and are not taken into account in the determination of the granulometry of the mineral material.

The inorganic and organic fillers can be used alone or as mixtures or are contained in the reaction mixture preferably in amounts of 0.5 to 50% by weight, with particular preference of 1 to 40% by weight, based on the weight of the components a) ae).

In addition, the polyurethane reaction mixture should contain drying agents, for example, zeolites. They are preferably added before the preparation of the reaction mixture according to the invention to compounds with at least two hydrogen atoms b) reactive to isocyanate or to the component containing the compounds with at least two hydrogen atoms b) reactive to the isocyanate. By addition of drying agents, the accumulation of water in the components or the reaction mixture is prevented, thereby preventing the formation of foamed polyurethane. As additives for the adsorption of water, aluminosilicates are preferably used, selected from the group of sodium aluminosilicates, potassium aluminosilicates, calcium aluminosilicates, cesium aluminosilicates, barium aluminosilicates, magnesium aluminosilicates, strontium aluminosilicates, sodium aluminophosphates, aluminophosphates potassium, calcium aluminophosphates and mixtures thereof. Especially preferred are mixtures of sodium, potassium and calcium aluminosilicates in castor oil as the support substance.

In order to improve the long-term stability of the cover layers according to the invention, it is also advantageous to add agents against the attack of small living beings. In addition, the addition of UV stabilizers is advantageous to avoid embrittlement of the molded bodies. These additives are known and are indicated, for example, in "Kunststoffhandbuch, Band 7, Polyurethane", Cari Hanser Verlag, 3. Auflage 1993, Kapitel 3.4.

The addition of components c), d) and e) is preferably carried out with compounds having at least two hydrogen atoms reactive with isocyanate groups. This mixture is referred to in the art often as a polyol component.

The combination of isocyanates with compounds with at least two hydrogen atoms reactive with isocyanate groups should be carried out in such a ratio that there is preferably a stoichiometric excess of isocyanate groups.

In a preferred embodiment of the invention, polyurethane reaction mixtures are used which lead to hydrophobic, essentially compact polyurethanes. As a compact polyurethane it is called a polyurethane which is essentially free of gaseous inclusions. Preferably, the density of a compact polyurethane is greater than 0.8 g / cm3, more preferably greater than 0.9 g / cm3 and especially greater than 1.0 g / cm3.

Other additives which can be used are, for example, materials which prevent runoff of the binder from the mineral material. As such additives, for example, organic fibers such as cellulose fibers can be added. In addition, you can also add polymers that are also already used today in the systems used bitumen-based. Above all, they are neoprene, styrene-butadiene-styrene block copolymers or their mixtures, as well as all other known gums and their mixtures. The additives can be added either directly to the mineral mixture in the form of powder or granules, or dispersed also in one of the polyurethane components.

The preparation of mixtures according to the invention containing crushed pavement, mineral material and a polymeric reaction mixture, as well as optionally other additives, is not limited. In this way, the preparation can be carried out, for example, in mixers in which the crushed pavement and the mineral material are incorporated and the starting components are incorporated to prepare the polyurethane reaction mixture, for example, by spraying. The additives that will eventually be added are in this case preferably added at the appropriate time to the mixture. In this way, they can be dissolved or dispersed, for example, in one of the components of the reaction mixture, for example, one of components a) to e), and they can be added together with them to the mixture. Also, the additives can also be added to the mixture separately. By way of example, the cellulosic fibers can be added at a point such that they are present homogeneously distributed in the mixture to prepare cover layers, but which are not destroyed by the mixing process. In this case, the mixture according to the invention can be prepared, for example, according to the process described in DE 19632638. It is also possible, for example, to first prepare the polyurethane reaction mixture and then mix it with the mineral material and eventually the other additives. Optionally, the mineral material may be mixed in another embodiment with some components of the reaction mixture, for example, with components b) and, if any, c) to e), and then adding the missing components, for example, component a) in a mixer. The preparation of the mixture according to the invention, which contains shredded pavement, can be carried out in a mobile manner at the site of incorporation. It is not necessary to transport to a central plant.

The hydrophobic polyurethane reaction mixtures used with preference are characterized by a particularly good malleability. In this way, these polyurethane reaction mixtures and the polyurethanes obtainable therefrom have a particularly good adhesion. Due to the hydrophobicity of the system, the hardening of the polyurethane reaction mixture is practically compact despite the presence of water, for example, rain.

When applying the mixture according to the invention to the base material, it is not necessary for the base material to be dry. Surprisingly, good adhesion between the carrier layer or the cover layer and the base material can also be obtained with the presence of dry base material.

The mixture according to the invention contains, in this case, preferably between 1 and 20% by weight, with particular preference between 2 and 15% by weight and especially between 4 and 10% by weight of the reaction mixture. polymer, with respect to the total weight of the mixture according to the invention containing crushed pavement, mineral material and a polymeric reaction mixture, as well as optionally other additives.

The bond between mineral material and binder according to the invention is very firm. In addition, in particular when using hydroxyl-functional compounds with hydrophobic groups, practically no hydrolytic degradation of the polyurethanes occurs and, thus, a very long durability of the cover layers produced according to the process according to the invention. The cover layers according to the invention are particularly carrier and, thus, suitable for all streets, roads and transit surfaces, especially for landing strips and streets of higher load class V to I, especially Ill to I and runways, where in the case of class V streets it is parallel service streets, in the case of class I streets, highways and fast lanes. In this case, the materials recommended for the relevant class are preferably used as mineral material.

Especially in case of using hydrophobic reaction mixtures, surprisingly less formation of freeze damage occurs. Another advantage of the cover layers according to the invention is the low expense in repairs. In this way, it is sufficient to prepare the mixture to make a cover layer in situ in small quantities without heating and apply it on the damaged place and seal. Beyond this, the mechanical properties of the cover layers according to the invention are not modified over the years.

Another advantage of the cover layers according to the invention is an improved resistance to sliding by moisture, especially with cover layers with a high percentage of polyurethane compared to cover layers with a high bituminous content.

Preferably, the mixture containing crushed pavement, mineral material and a polymeric reaction mixture, as well as optionally other additives, is compacted after applying it on a base material. The intensity of the compaction is governed in this case according to the desired application. In this way, for example, for the preparation of asphalt with drainage that allows moisture to flow, it is only compacted a little, for the preparation of rechargeable asphalt, it is more compact. The necessary compaction is also governed by the composition of the stone.

Preferably, the method according to the invention is used for street renovation. In this case, the crushed pavement is preferably obtained directly at the site of application by removal with milling of the street that requires sanitation. Preferably, the material obtained by milling is split, crushed and / or sieved to obtain a preferred granulometry. This recycled material is mixed with binders and other mineral material and preferably is incorporated in situ again as carrier layer or cover layer in the street. For it, the corresponding base is preferentially treated with conventional mediators of adhesion systems, for example, with polyurethane-based spraying adhesives. This serves to further improve the adhesion between the layers and compensate the stresses that are produced by heavy load, for example, by heavy load transit or different coefficients of thermal expansion between the base and the carrier layer or the cover layer. The incorporation is made in this case with a usual equipment in the construction of streets. Here, the equipment used for the incorporation preferably has a non-stick coating or is cross-linked with a separating agent, preferably with a biological base. Preferably, the incorporated cover layer is then sprayed with fine-grained mineral material (eg, sand) to further improve the good properties of anti-slip in humidity.

Compared to the conventional process in which the new asphalt is only obtained in stationary asphalt plants, time and energy can be saved by means of the method according to the invention eliminating the otherwise necessary transport of trucks. Beyond this, roads, streets and traffic surfaces are characterized by a very high durability, especially with freeze-thaw cycles, high elasticity and extraordinary resistance. Thus, the cover layers according to the invention combine the positive properties of bitumen-based cover layers with cover layers based on polymeric reaction mixtures, such as polyurethanes or epoxides.

Next, the invention is clarified in the context of the example: Polyurethane reaction mixture 1: 100 parts by weight of the polyol component of the elastane system 6551/101 and 50 parts by weight of IsoPMDI 92140, a preparation with diphenylmethane diisocyanate (MDI) were mixed together. 10 parts by weight of the polyurethane reaction mixture 1 are mixed with 90 parts by weight of a mixture of 90 parts by weight of mineral mixture (grain size 2/5, Piesberger) and 10 parts by weight of a standard recycled material Based on bitumen split from an asphalt cover layer in a mixing unit, they are poured into a of 100 x 100 x 100 mm, compacted with 8.5 N / mm2 and hardened.

The compressive strength of the prepared sample was determined after storage for more than 24 hours and is 7.0 N / mm2. This value shows that it is possible to manufacture cover layers of such material.

Claims (1)

1. CLAIMS Method for preparing streets, roads and other traffic surfaces, characterized in that a mixture is prepared, which contains crushed pavement, mineral material and / or glass, a polymeric reaction mixture and, if necessary, other additives, is applied to a base material and hardens Process according to claim 1, characterized in that the polymer reaction mixture is a mixture for preparing an epoxy resin or a polyurethane. Process according to claim 2, characterized in that the polymer reaction mixture contains a compound to improve the adhesion. Process according to claim 1 to 3, characterized in that the polymer reaction mixture can be obtained by mixing: a) isocyanates with b) compounds with at least two hydrogen atoms reactive to the isocyanate, as well as eventually c) chain extenders and / or crosslinkers, d) catalysts and e) other additives. Process according to one of claims 1 to 4, characterized in that the proportion of the polymeric reaction mixture in the mixture containing crushed pavement, mineral material and / or glass, a polymeric reaction mixture and optionally other additives, is 1 to 20% by weight, based on the total weight of the mixture. Process according to one of claims 1 to 5, characterized in that the proportion of crushed pavement is less than 95% by weight, with respect to the total weight of the mixture of crushed pavement and mineral material. Cover layers or bearing layers for streets, roads and other transit surfaces, characterized in that they can be obtained according to one of claims 1 to 5.