DE102004009509A1 - Stabilising sandy soil, e.g. when building roads, embankments, tunnels or parking areas, involves adding a combination of film-forming polymer and quick-setting cement - Google Patents

Abstract

Sandy soil is stabilised by treatment with a combination of a film-forming polymer and a cement with a water-binding capacity of at least 50 wt% and/or an early strength value (after 12 hours) which is at least 30% of the final strength. A method for stabilising sandy soil (I) involves incorporating into the soil (i) a finely-divided, water-insoluble, film-forming polymer (P) with a minimum film-forming temperature (MFT) of not above 30[deg]C in amounts of 0.1-10 wt% based on the solid content of (I), and (ii) 0.5-10 wt% of cement with a water-binding capacity of at least 50 wt% and/or an early strength value (DIN EN 196-1; at 20[deg]C after 12 hours) which is at least 30% of the final strength.

Description

The The present invention relates to a method for solidifying sand-containing Floors.

A Variety landscaping construction measures, such as Landfill, embankment and dyke construction, road construction, in particular the road substructure, as well as the creation of embankments and parking lots require often a solidification of the soil used. Also in tunneling, especially in Floors of the Soil classes 3 to 5 (according to DIN 18300) it is often necessary soil to solidify.

Lots such fastening measures based on the use of clay soil, d. H. Soils with a Clay content of usually more than 20 wt .-%. Have clayey soils but on the one hand the disadvantage that they are not suitable for all of the above construction measures, e.g. For the landfill construction, are suitable. More serious, however, is that clayey Soils are not common available on site and therefore be transported there at great expense would need where the respective construction measure carried out shall be. In addition, in some cases, the improvement of the mechanical Strength and in particular the cohesion of the clay-containing soils built building project desirable, especially since these properties are detrimental by the action of water to be influenced.

It has therefore been lacking in attempts, soils, especially sand-containing Soils with a clay content <20 Wt .-% and in particular <10 % By weight, usually have only a very low mechanical strength, by addition from solid binders. This has happened several times about that reports the mechanical properties of sandy soils through Addition of lime, mostly in the form of so-called quicklime (calcium oxide) or by adding cement. In fact, the leads Addition of such materials, in part, to improved strength, in particular improved resistance to pressure loading. The inner one However, the strength of the soil material (cohesion) is only moderate. moreover have such measures usually an undesirable embrittlement, i.e. a loss of elasticity of the Soil material, and made the so treated soil material for many Applications inappropriate.

on several occasions was in the literature about it reported soils solidify by use of polymers. That's how it describes GB 907,182 the use of a partially hydrolyzed polyvinyl acetate with a degree of salification of 75 to 95 mol% and a degree of polymerization of at least 500 for the consolidation of soil. The polymer will used in an amount of less than 2 wt .-%.

The J6 00 04 587 A describes the use of aqueous acrylate dispersions to protect soil against Erosion. As a result, a solidification of the soil up to a Depth of only about 10 cm.

The FR 2464977 describes the use of aqueous emulsion polymers for solidifying sand or sand-containing soils. The solidified sand is used to build driveable areas such as parking lots.

The J0 22 83 792 describes a composition for fixing Earth materials and to protect earth structures against erosion, to 100 parts by weight of bentonite 5 to 70 parts by weight of a re-emulsifiable Polymer powder and 5 to 50 parts by weight of a water-soluble Polymer powder included. The solidifying effect of such Powder, especially the cohesive However, properties of the so consolidated soil material are not satisfactory.

Out WO 02/48068 in turn Erdbaustoffe are known, in addition to a Main mineral constituent based on sand, grit and / or Gravel at least one uniformly distributed in the main mineral constituent, water-insoluble, contain film-forming polymer. The proportion of polymer in the Erdbaustoff amounts preferably at least 2 parts by weight per 100 parts by weight of mineral Ingredients to a sufficient strength and in particular a cohesion to reach the Erdbaustoffs.

All of the above-mentioned measures, which use an aqueous polymer dispersion or a polymer powder that can be re-emulsified to solidify sand-containing soil materials, has in common that solidification of the soil can generally only be achieved to a depth of about 10 cm and moist or wet soils, such as in dam and dike construction and especially in landfill and tunnel construction occur in this way can not be sufficiently solidified. Own investigations by the Applicant suggest that this is due to the fact that the polymers contained in the aqueous dispersions and the re-emulsifiable polymer powders can only develop a solidifying effect if the moisture contained in the soils can largely escape at least temporarily. However, this is usually guaranteed only to a depth of about 10 cm. A solidification of the soil in greater depth or a moist soil can not be achieved with these measures.

Of the The present invention is based on the object, a method for solidifying sand-containing soil materials, the overcomes the disadvantages of the prior art and in particular solidifying wet or wet soils and / or soils in one Depth of more than 10 cm allows without any embrittlement the solidified soil material enters.

The Applicant has now found that the problems described here solved can be, if one in the sandy soil a finely divided, insoluble in water Polymer in small amount, d. H. in an amount of 0.5 to 10 wt .-%, based on the solid components of the soil, and a Cement incorporates the cement by a water binding capacity of at least 50% by weight, based on the dry weight of the cement, and / or by an early strength according to DIN EN 196 characterized after 12 hours of at least 30% of the final strength is. This surprises since the for the consolidation of sand or sandy soils variously proposed Hydraulic binder with low early strength and low water binding capacity such Portland cement in the consolidation of sandy soils to a embrittlement of the soil and thus an undesirable one loss of elasticity have as a consequence.

• i) wenigstens eines feinteiligen, in Wasser nicht löslichen filmbildenden Polymerisats P mit einer Mindestfilmbildetemperatur MFT ≤ 30°C in einer Menge von 0,1 bis 10 Gew.-%, bezogen auf die festen Bestandteile des sandhaltigen Bodenmaterials, und
• ii) wenigstens eines Zements in einer Menge von 0,5 bis 10 Gew.-%, bezogen auf die festen Bestandteile des sandhaltigen Bodenmaterials, wobei der Zement durch ein Wasserbindevermögen von wenigstens wenigstens 50 Gew.-%, bezogen auf das Gewicht des Zements, und/oder durch eine Frühfestigkeit gemäß DIN EN 196 nach 12 h bei 20°C von wenigstens 30% der Endfestigkeit charakterisiert ist,

einarbeitet. Alle Mengenangaben beziehen sich auf die festen Bestandteile bzw. den Feststoffgehalt des Bodenmaterials. Der Feststoffgehalt wird durch 24-stündiges Trocknen des Bodenmaterials bei 120°C bestimmt. Alle Mengenangaben, welche das erfindungsgemäß enthaltene Polymerisat, gegebenenfalls im Polymerisat enthaltene Zusatz- und Hilfsstoffe betreffen, sind als Feststoff gerechnet, sofern nichts anderes angegeben ist. Die Feststoffgehalte der Polymerisate und der darin gegebenenfalls enthaltenen Zusatz- und Hilfsstoffe werden durch Trocknen bei 120°C bis zur Gewichtskonstanz bestimmt.Accordingly, the present invention relates to a method for consolidating sand-containing soil materials, wherein the sand-containing soil material

• i) at least one finely divided, water-insoluble film-forming polymer P having a minimum film-forming temperature MFT ≤ 30 ° C in an amount of 0.1 to 10 wt .-%, based on the solid constituents of the sandy soil material, and
• ii) at least one cement in an amount of from 0.5 to 10% by weight, based on the solid constituents of the sand-containing soil material, the cement having a water-binding capacity of at least at least 50% by weight, based on the weight of the cement, and / or characterized by an early strength according to DIN EN 196 after 12 h at 20 ° C of at least 30% of the final strength,

incorporated. All quantities are based on the solid constituents or the solids content of the soil material. The solids content is determined by drying the soil at 120 ° C for 24 hours. All amounts which relate to the polymer according to the invention, optionally contained in the polymer additives and auxiliaries, are calculated as a solid, unless otherwise specified. The solids contents of the polymers and the additives and auxiliaries optionally contained therein are determined by drying at 120 ° C. to constant weight.

• – 25 bis 100 Gew.-%, speziell 50 bis 100 Gew.-% Sand (Korngröße 0,063 bis 2,0 mm);
• – 0 bis 75 Gew.-%, insbesondere 0 bis 50 Gew.-%, z.B. 5 bis 50 Gew.-% Schluff (Korngröße 0,002 bis 0,063 mm),
• – 0 bis 10 Gew.-% Ton (Korngröße < 0,002 mm) und
• – 0 bis 30 Gew.-% Grobsand oder Feinkies (Korngröße 2 bis 6,3 mm) und
• – 0 bis 10 Gew.-% Mittel- oder Grobkies oder Steinen bestehen.

Under soils or soil materials are understood according to the invention both natural soils, ie soils that have been created by erosive processes, as well as soil materials that were obtained by mining or other processes from natural resources, such as excavated earth, flushing sand, etc. The term sandhaltig here Soils or soil materials, which account for a predominant proportion, ie more than 50 wt .-%, preferably at least 70 wt .-% of silt and / or sand (according to DIN 4022) or sand (according to the classification of v Engelhard), ie from clastic sediments with a grain size of 0.002 to 2 mm. In addition, the soils can also lower proportions of up to 20%, preferably not more than 10 wt .-% of clay (<0.002 mm), and up to 30 wt .-%, preferably not more than 20 wt .-% fine Medium or coarse gravel (particle size 2 to 63 mm). In particular, the inventive method for solidifying soils or soil materials, the 0 to 75 wt .-% and in particular 25 to 50 wt .-% silt, ie components having a particle size of 0.002 to 0.063 mm, and 25 to 100 wt. %, in particular 50 to 100% by weight of sand, ie constituents having a particle size in the range of 0.063 to 2 mm. These soils preferably contain no more than 10% by weight of clay, ie soil materials with a particle size <0.002 mm. Among them, soils are particularly suitable, consisting of:

• - 25 to 100 wt .-%, especially 50 to 100 wt .-% sand (particle size 0.063 to 2.0 mm);
• From 0 to 75% by weight, in particular from 0 to 50% by weight, for example from 5 to 50% by weight of silt (particle size from 0.002 to 0.063 mm),
• - 0 to 10 wt .-% clay (particle size <0.002 mm) and
• - 0 to 30 wt .-% coarse sand or fine gravel (grain size 2 to 6.3 mm) and
• - 0 to 10 wt .-% medium or coarse gravel or stones exist.

Basically you can However, also achieve a strengthening effect for those soils that have a clay content greater than 10% by weight, e.g. 10 to 30 wt .-% have.

The Type of clastic sediments is for the inventive method of secondary importance. As a rule, these are mineral, which for the most part Proportion, i. usually at least 80 wt .-% of quartz, silicates or aluminosilicates, for example clay minerals and feldspars, and in minor quantities also other minerals Ingredients like heavy minerals, carbonates like lime or dolomite or aluminum-rich minerals such as bauxite, oxidic minerals, especially iron oxides and the like may contain. Basically leave But also soils with a low quartz content, for example, those with a solidify high lime content according to the invention.

Next the aforesaid clastic sediments, which are usually inorganic materials can act the floors also organic components such as plant remains, grass, straw, pieces of wood, wood or cork chips, Humus or peat contain, as these the solidifying effect of Do not adversely affect cement / polymer mixture. Because it However, if this is valuable, their share in the Usually not more than 20% by weight, preferably not more than 10% by weight of the soil material.

The This invention has a number of advantages: the method allows solidifying soils even at a depth of more than 10 cm below the ground surface, without that a significant loss of elasticity occurs. The procedure also allows solidification of moist soils, especially those soils with a water content of up to 30% by weight, e.g. 5 to 30 wt .-%, and in particular 5 to 20 wt .-%, based on the solid constituents of the soil. The method is especially for solidification moderate or slightly damp soils (Water content <5% by weight) as well as dry soils (Water content <1 % By weight suitable). Furthermore will provide sufficient soil strength even at lower polymer levels achieved as with the sole use of polymer, whereby the Process more cost-effective is.

According to the invention can as Polymers i basically all finely divided polymers are used in water not soluble are and which are able, at temperatures ≤ 30 ° C and in particular ≤ 20 ° C, a polymer film to form, i. are film-forming at these temperatures. Suitable are thus basically All polymers having a minimum film-forming temperature ≤ 30 ° C, in particular ≤ 20 ° C and particularly preferably ≤ 10 ° C. The minimum film-forming temperature Here is the minimum temperature from which a finely divided Polymer forms a closed polymer film.

Uniform film formation of the polymer i in the soil materials is generally ensured when the polymer has a glass transition temperature T _g ≦ 30 ° C., preferably ≦ 25 ° C., in particular ≦ 10 ° C., more preferably ≦ 0 ° C., and very particularly preferably ≤ -5 ° C shows. The glass transition temperature is understood here to be the "midpoint temperature" determined by differential thermal analysis (DSC) according to ASTM D3418-82 (see also Zosel, Farbe und Lack 82 (1976), pp. 125-134 and DIN 53765). For a sufficient strength of the consolidated soil materials, it is advantageous if the glass transition temperature of the polymer at least -50 ° C, preferably at least -40 ° C. The glass transition temperature of polymers made up of ethylenically unsaturated monomers can be controlled in a known manner via the monomer composition (TG Fox, Bull. Am. Phys Soc. (Ser. II) 1, 123 [1956] and Ullmanns Enzyklopedia of Industrial Chemistry 5th ed., Vol. A21, Weinheim (1989) p. 169).

In preferred embodiments the present invention is the glass transition temperature Tg of the polymer in the range of -50 ° C to + 25 ° C, preferably - -40 ° C to + 5 ° C and especially -35 ° C to -5 ° C. Glass transition temperatures in this area are beneficial as they make a good filming of the Polymerisats even at low ambient temperatures and thus an advantageous mechanical strength with simultaneous elasticity of Bodenmateriermöglichen, without being raised Temperatures must be dried or solidified.

This is according to the invention polymer used is insoluble in water and advantageously shows in the filmed state only a small water absorption, i. the Water absorption is below 40 g / 100 g of polymer film, in particular below 10 g / 100 g of polymer film, and more preferably below 1 g / 100 g of polymer film.

preferred Polymers are composed of ethylenically unsaturated monomers M, which usually at least 80 wt .-%, in particular at least 90th Wt .-%, ethylenically unsaturated Monomers M with a water solubility <10 g / l (25 ° C and 1 bar) comprising up to 30% by weight, e.g. 5 to 25 wt .-% of the monomers A may be replaced by acrylonitrile and / or methacrylonitrile. Besides The monomers A contain 0.5 to 20 wt .-% of the monomers A different monomers B. Here and below are all quantities for monomers in wt .-% based on 100 wt .-% monomers M.

• – Ester einer a,b-ethylenisch ungesättigten C₃-C₆-Monocarbonsäure oder C₄-C₈-Dicarbonsäure mit einem C₁-C₁₀-Alkanol. Vorzugsweise handelt es sich dabei um Ester der Acrylsäure oder Methacrylsäure, wie Methyl(meth)acrylat, Ethyl(meth)acrylat, n-Butyl(meth)acrylat, t-Butyl(meth)acrylat, 2-Ethylhexyl(meth)acrylat etc.;
• – vinylaromatische Verbindungen, wie Styrol, 4-Chlorstyrol, 2-Methylstyrol etc.;
• – Vinylester aliphatischer Carbonsäuren mit vorzugsweise 1 bis 10 C-Atomen, wie Vinylacetat, Vinylpropiat, Vinyllaurat, Vinylstearat, Versaticsäurevinylester etc.;
• – Olefinen, wie Ethylen oder Propylen;
• – konjugierten Diolefinen, wie Butadien oder Isopren;
• – Vinylchlorid oder Vinylidenchlorid.

Monomers A are usually simply ethylenically unsaturated or conjugated diolefins. Examples of monomers A are:

• - Esters of a, b-ethylenically unsaturated C ₃ -C ₆ monocarboxylic acid or C ₄ -C ₈ dicarboxylic acid with a C ₁ -C ₁₀ alkanol. These are preferably esters of acrylic acid or methacrylic acid, such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, etc. ;
• Vinyl aromatic compounds such as styrene, 4-chlorostyrene, 2-methylstyrene, etc .;
• Vinyl esters of aliphatic carboxylic acids having preferably 1 to 10 carbon atoms, such as vinyl acetate, vinyl propoxide, vinyl laurate, vinyl stearate, vinyl versatate, etc .;
• - olefins, such as ethylene or propylene;
• Conjugated diolefins, such as butadiene or isoprene;
• - Vinyl chloride or vinylidene chloride.

• I) Copolymerisate von Styrol mit Alkyl(acrylaten), d.h. Copolymerisate, die als Monomer A Styrol und wenigstens einen C₁-C₁₀-Alkylester der Acrylsäure und gegebenenfalls einen oder mehrere C₁-C₁₀-Alkylester der Methacrylsäure einpolymerisiert enthalten;
• II) Copolymerisate des Styrols mit Butadien, d.h. Copolymerisate die als Monomer A Styrol und Butadien sowie gegebenenfalls (Meth)acrylsäureester von C₁-C₈-Alkanolen, Acrylnitril und/oder Methacrylnitril einpolymerisiert enthalten;
• III) Homo- und Copolymerisate von Alkyl(meth)acrylaten (Reinacrylate), d.h. Homo- und Copolymerisate, die als Monomere A wenigstens einen C₁-C₁₀-Alkylester der Acrylsäure und/oder einen C₁-C₁₀-Alkylester der Methacrylsäure einpolymerisiert enthalten, insbesondere Copolymere, die als Monomere A Methylmethacrylat, wenigstens einen C₁-C₁₀-Alkylester der Acrylsäure und gegebenenfalls einen C₂-C₁₀-Alkylester der Methacrylsäure einpolymerisiert enthalten;
• IV) Homo- und Copolymerisate von Vinylestern aliphatischer Carbonsäuren und Copolymerisate von Vinylestern aliphatischer Carbonsäuren mit Olefinen und/oder Alkyl(meth)acrylaten, d.h. Homo- und Copolymerisate, die als Monomer A wenigstens einen Vinylester einer aliphatischen Carbonsäure mit 2 bis 10 C-Atomen und gegebenenfalls ein oder mehrere C₂-C₆-Olefine und/oder gegebenenfalls einen oder mehrere C₁-C₁₀-Alkylester der Acrylsäure und/oder der Methacrylsäure einpolymerisiert enthalten.

Preferred film-forming polymers are selected from the polymer classes I to IV listed below:

• I) copolymers of styrene with alkyl (acrylates), ie copolymers containing in copolymerized form as monomer A styrene and at least one C ₁ -C ₁₀ -alkyl ester of acrylic acid and optionally one or more C ₁ -C ₁₀ -alkyl esters of methacrylic acid;
• II) copolymers of styrene with butadiene, ie copolymers containing in copolymerized form as monomer A styrene and butadiene and optionally (meth) acrylic esters of C ₁ -C ₈ -alkanols, acrylonitrile and / or methacrylonitrile;
• III) Homopolymers and copolymers of alkyl (meth) acrylates (pure acrylates), ie homopolymers and copolymers containing as monomers A at least one C ₁ -C ₁₀ alkyl ester of acrylic acid and / or a C ₁ -C ₁₀ alkyl ester of methacrylic acid in copolymerized form, in particular copolymers containing in copolymerized form as monomers A methyl methacrylate, at least one C ₁ -C ₁₀ alkyl ester of acrylic acid and optionally a C ₂ -C ₁₀ alkyl ester of methacrylic acid;
• IV) homopolymers and copolymers of vinyl esters of aliphatic carboxylic acids and copolymers of vinyl esters of aliphatic carboxylic acids with olefins and / or alkyl (meth) acrylates, ie homopolymers and copolymers containing as monomer A at least one vinyl ester of an aliphatic carboxylic acid having 2 to 10 carbon atoms and optionally one or more C ₂ -C ₆ -olefins and / or optionally one or more C ₁ -C ₁₀ -alkyl esters of acrylic acid and / or methacrylic acid in copolymerized form.

Typical C ₁ -C ₁₀ -alkyl esters of acrylic acid in the copolymers of class I to IV are ethyl acrylate, n-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate and 2-ethylhexyl acrylate.

Typical copolymers of class I contain, as monomers A, 20 to 80% by weight and in particular 30 to 70% by weight of styrene and 20 to 80% by weight, in particular 30 to 70% by weight, of at least one C ₁ -C ₁₀ alkyl esters of acrylic acid such as n-butyl acrylate, ethyl acrylate or 2-ethylhexyl acrylate, each based on the total amount of the monomers A.

Typical copolymers of class II comprise, as monomers A, in each case based on the total amount of monomers A, 30 to 85% by weight, preferably 40 to 80% by weight and more preferably 50 to 75% by weight of styrene and 15 to 70 Wt .-%, preferably 20 to 60 wt .-% and particularly preferably 25 to 50 wt .-% butadiene wherein 5 to 20 wt .-% of the aforementioned monomers A by (meth) acrylic acid esters of C ₁ -C ₈ alkanols and or may be replaced by acrylonitrile or methacrylonitrile.

Typical copolymers of class III comprise, as monomers A, in each case based on the total amount of monomers A, from 20 to 80% by weight, preferably from 30 to 70% by weight, of methyl methacrylate and at least one further, preferably one or two, further monomers selected from Acrylic acid esters of C ₁ -C ₁₀ -alkanols, in particular n-butyl acrylate, 2-ethylhexyl acrylate and ethyl acrylate and optionally a methacrylic acid ester of a C ₂ -C ₁₀ -alkanol in a total amount of 20 to 80 wt .-% and preferably 30 to 70 wt. -% polymerized.

Typical copolymers of class IV contain, as monomers A, in each case based on the total amount of monomers A, from 30 to 90% by weight, preferably from 40 to 80% by weight and particularly preferably from 50 to 75% by weight, of a vinyl ester of an aliphatic carboxylic acid , in particular vinyl acetate and 10 to 70 wt .-%, preferably 20 to 60 wt .-% and particularly preferably 25 to 50 wt .-% of a C ₂ -C ₆ olefin, in particular ethylene and optionally one or two further monomers selected copolymerized under (meth) acrylic acid esters of C ₁ -C ₁₀ -alkanols in an amount of 1 to 15 wt .-%.

Under the polymers mentioned above are the polymers of the class I, II and III particularly suitable.

When Monomers B come in principle all monomers other than the aforementioned monomers and copolymerizable with the monomers A. Such monomers are known in the art and usually serve the modification the properties of the polymer.

Preferred monomers B are selected from monoethylenically unsaturated mono- and dicarboxylic acids having 3 to 8 carbon atoms, in particular acrylic acid, methacrylic acid, itaconic acid, their amides such as acrylamide and methacrylamide, their N-alkylolamides such as N-methylolacrylamide and N-methylolmethacrylamide, their hydroxy C ₁ -C ₄ -alkyl esters such as 2-hydroxyethyl acrylate, 2- and 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2- and 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate and monoethylenically unsaturated monomers with oligoalkylene oxide chains, preferably with polyethylene oxide chains having degrees of oligomerization preferably in the range from 2 to 200, for example monovinyl and monoallyl ethers of oligoethylene glycols and also esters of acrylic acid, maleic acid or methacrylic acid with oligoethylene glycols.

Of the Proportion of monomers with acid groups is preferably not more than 10% by weight and in particular not more as 5% by weight, e.g. 0.1 to 5 wt .-%, based on the monomers M. The proportion of hydroxyalkyl esters and monomers with oligoalkylene oxide chains if included, is preferably in the range of 0.1 to 20 Wt .-% and in particular in the range of 1 to 10 wt .-%, based to the monomers M. The proportion of amides and N-alkylol amides is if included, preferably in the range of 0.1 to 5 wt .-%.

In addition to the abovementioned monomers B, other monomers B also include crosslinking monomers, such as glycidyl ethers and esters, for example vinyl, allyl and methallyl glycidyl ethers, glycidyl acrylate and methacrylate, the diacetonylamides of the abovementioned ethylenically unsaturated carboxylic acids, for example diacetone (meth) acrylamide, and the esters of acetylacetic acid with the abovementioned hydroxyalkyl esters of ethylenically unsaturated carboxylic acids, for example acetylacetoxyethyl (meth) acrylate. Monomers B furthermore include compounds which have two nonconjugated, ethylenically unsaturated bonds, for example the di- and oligoesters of polyhydric alcohols with α, β-monoethylenically unsaturated C ₃ -C ₁₀ -monocarboxylic acids, such as alkylene glycol diacrylates and dimethacrylates, for example ethylene glycol diacrylate, 1 , 3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, propylene glycol diacrylate, and further divinylbenzene, vinyl methacrylate, vinyl acrylate, allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, methylenebisacrylamide, cyclopentadienyl acrylate, tricyclodecenyl (meth) acrylate, N, N'-divinylimidazolin-2-one or Triallyl cyanurate into consideration. The proportion of crosslinking monomers is generally not more than 1 wt .-%, based on the total amount of monomer and will not exceed 0.1 wt .-% in particular.

Farther as monomers B are also vinylsilanes, e.g. vinyltrialkoxy suitable. These are, if desired, in an amount of 0.01 to 1 wt .-%, based on the total amount of monomer in the preparation the polymers used.

In order to achieve a uniform distribution of the polymer in the earthworks, it has proven useful when the polymer is used in the form of finely divided particles. Fine-particle polymers are understood as meaning those whose weight-average particle diameter d ₅₀ does not exceed 10 μm and in particular 2 μm. In particular, the weight average particle diameter d _{50 of} the polymer particles is in the range from 50 to 2000 nm and especially in the range from 100 to 1000 nm. The weight average particle diameter d ₅₀ is the particle diameter which is less than 50% by weight of the polymer particles. The weight-average particle diameter of a polymer can be determined in a known manner on an aqueous dispersion of the particles by quasi-elastic light scattering or by measurement in an ultracentrifuge.

Polymers having particle diameters of this type are generally present as aqueous polymer dispersions or in the form of powders which are obtained from these dispersions by removing the water, in particular by evaporation and especially by spray drying are available. For use in the process according to the invention, therefore, polymers in the form of aqueous polymer dispersions, in particular those obtainable by free-radical aqueous emulsion polymerization of the abovementioned ethylenically unsaturated monomers, are preferred. Likewise preferred are polymer powders prepared therefrom and aqueous dispersions obtainable by redispersing the polymer powders in water. Methods for the preparation of aqueous polymer dispersions as well as for the preparation of polymer powders from aqueous polymer dispersions are described extensively in the prior art (see, for example, D. Distler, Aqueous Polymer Dispersions, Wiley VCH, Weinheim 1999, H. Warson, Synthetic Resin Emulsions, Ernest Benn Ltd., London 1972, pp. 193-242 and EP-A 11821179; for the preparation of polymer powders, see also WO 98/03577 and WO 98/03576, the disclosure of which is hereby incorporated by reference). Both aqueous polymer dispersions and the powders produced therefrom are also commercially available, eg under the brands ACRONAL® ^®, STYRONAL® ^®, Butofan ^® and Styrofan ^® BASF Aktiengesellschaft, Ludwigshafen, Germany, VINNOFIL ^® and VINNAPAS ^® from. Wacker Chemie GmbH , Burghausen, and RHODIMAX ^® from. Rhodia SA

The radical, watery Emulsion polymerization of the monomers M takes place in the presence at least a surface active Substance and at least one radical polymerization initiating, preferably water-soluble Initiator at temperatures preferably in the range of 20 to 120 ° C.

When Initiators come azo compounds, organic or inorganic Peroxides, salts of peroxodisulfuric acid and redox initiator systems into consideration. Preference is given to using a salt of peroxydisulphuric acid, in particular a sodium, potassium or Ammonium salt or a redox initiator system, which acts as an oxidizing agent Hydrogen peroxide or an organic peroxide such as tertiary butyl hydroperoxide and as reducing agent contains a sulfur compound which especially selected is among sodium hydrogen sulfite, sodium hydroxymethanesulfinate and the bisulfite adduct to acetone.

When surfactants Substances usually come for the Emulsion polymerization used emulsifiers and protective colloids into consideration. Preferred emulsifiers are anionic and nonionic Emulsifiers, in contrast to the protective colloids in general have a molecular weight below 2000 g / mol and in amounts from up to 0.2 to 10 wt .-%, preferably 0.5 to 5 wt .-%, based on the polymer in the dispersion or to be polymerized Monomers M are used.

The anionic emulsifiers include alkali metal and ammonium salts of alkyl sulfates (alkyl radical: C ₈ -C ₂₀ ), of sulfuric monoesters of ethoxylated alkanols (EO degree: 2 to 50, alkyl radical: C ₈ to C ₂₀ ) and ethoxylated alkylphenols (EO degree: 3 to 50, alkyl radical: C ₄ -C ₂₀ ), of alkylsulfonic acids (alkyl radical: C ₈ to C ₂₀ ), of sulfonated mono- and di-C ₆ -C ₁₈ -alkyldiphenyl ethers, as described in US Pat. No. 4,269,749 , and of alkylarylsulfonic acids (alkyl radical: C ₄ -C ₂₀ ). Further suitable anionic emulsifiers can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular substances, Georg-Thieme-Verlag, Stuttgart, 1961, pp. 192-208.

Suitable nonionic emulsifiers are araliphatic or aliphatic nonionic emulsifiers, for example ethoxylated mono-, di- and trialkylphenols (EO degree: 3 to 50, alkyl radical: C ₄ -C ₉ ), ethoxylates of long-chain alcohols (EO degree: 3 to 50, alkyl radical : C ₈ -C ₃₆ ), as well as polyethylene oxide / polypropylene oxide block copolymers. Preferred are ethoxylates of long-chain alkanols (alkyl radical: C ₁₀ -C ₂₂ , average degree of ethoxylation: 3 to 50) and particularly preferably those based on oxo alcohols and native alcohols with a linear or branched C ₁₂ -C ₁₈ -alkyl radical and a degree of ethoxylation of 8 until 50.

In the process according to the invention, preference is given to using aqueous polymer dispersions or powders prepared therefrom which contain at least one anionic emulsifier, in particular a salt and especially alkali metal salts of the sulfonated mono- and di-C ₆ -C ₁₈ -alkyldiphenyl ethers described in US Pat. No. 4,269,749, or combinations of contain at least one anionic and one nonionic emulsifier.

In specific embodiments of the present invention, it may be advantageous to use polymers which contain at least one alkoxylated, preferably ethoxylated nonionic emulsifier and / or at least one alkoxylated, preferably ethoxylated anionic emulsifier, for example one of the abovementioned. Preferably, the amount of these emulsifiers in the range of 0.1 to 3.5 wt .-%, particularly preferably 0.2 to 3 wt .-%, based on the total weight of all copolymerized monomers. The alkoxylated emulsifier or the alkoxylated emulsifiers can be added after the preparation of the polymers or preferably used for their preparation. Depending on the nature of the soil used for the production of Erdbaustoffe such alkoxylated emulsifiers can improve both the manufacturability and the processing properties and increase the mechanical strength and the reduce possible shrinkage during drying or hardening of the earthworks.

suitable Protective colloids are, for example, polyvinyl alcohols, starch and Cellulose derivatives, carboxyl group-containing polymers such as homo- and copolymers of acrylic acid and / or methacrylic acid Comonomers such as styrene, olefins or hydroxyalkyl esters, or vinylpyrrolidone containing homopolymers and copolymers. A detailed description of others suitable protective colloids can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular substances, Georg-Thieme-Verlag, Stuttgart 1961, pp. 411-420. Mixtures of emulsifiers and / or protective colloids can also be used.

Of course you can the molecular weight of the polymers by adding regulators in one small amount, usually up to 2 wt .-%, based on the polymerizing Monomers M, can be adjusted. As a regulator come in particular organic Thio compounds, further allyl alcohols and aldehydes into consideration. In the preparation of the butadiene-containing polymers of the class I become frequent Regulator in an amount of 0.1 to 2 wt .-%, preferably organic Thio compounds such as tert-dodecylmercaptan used.

in the It is optionally connected to the actual polymerization reaction required, the inventive, aqueous Polymerisate dispersions largely free of odorants, such as Residual monomers and other organic volatiles. This can be done physically in a conventional manner by distillation Distance (especially over Steam distillation) or by stripping with an inert Gas can be achieved. The lowering of the residual monomers can continue chemically by free radical postpolymerization, in particular Exposure of redox initiator systems, as e.g. in DE-A 44 35 423, DE-A 44 19 518 and in DE-A 44 35 422 are listed, respectively. The postpolymerization with a redox initiator system is preferred of at least one organic peroxide and one organic sulfite carried out.

To Termination of the polymerization become the polymer dispersions used before their use according to the invention often alkaline, preferably to pH in the range of 7 to 10. For neutralization can ammonia or organic amines, and preferably hydroxides, such as Sodium hydroxide, potassium hydroxide or calcium hydroxide can be used.

to Preparation of polymer powders are the aqueous polymer dispersions in a known manner a drying process, preferably in the presence of conventional Drying aid, subjected. Preferred drying method is the spray drying. If necessary, the drying aid is in an amount from 1 to 30 wt .-%, preferably 2 to 20 wt .-%, based on the Used polymer content of the dispersion to be dried.

Of the Solids content of the polymer dispersion to be dried, already containing the drying aids or is usually in the range from 10 to 60% by weight, preferably in the range from 20 to 55% by weight (calculated in each case as a polymer + drying assistant, based on the total weight of the dispersion).

at the spray drying the polymer dispersions to be dried in the presence of Drying aid in a drying tower through which a stream of hot air guided is dried. The temperature of the hot air flow is in the Usually at the entrance of the drying tower 100 to 200 ° C, preferably 110 to 170 ° C, and on Tower exit about 30 to 100 ° C, preferably 50 to 80 ° C. The polymer dispersion to be dried can be used against the stream of hot air or preferably be introduced in parallel in the hot air stream. The addition can over Single or multi-fluid nozzles or over take a rotating disc. The deposition of the polymer powder takes place in usual Way, e.g. using cyclones or filter separators.

Suitable drying aids are all drying aids customarily used, for example homopolymers and copolymers of vinylpyrrolidone, homo- and copolymers of acrylic acid and / or methacrylic acid with monomers carrying hydroxyl groups, vinylaromatic monomers, olefins and / or (meth) acrylic esters, polyvinyl alcohol and, in particular, arylsulfonic acid Formaldehyde condensation products and mixtures thereof, into consideration. In principle, the drying agents can be added during the drying process in the form of solutions, for example as aqueous or aqueous-alcoholic solutions, to the polymer dispersion to be dried. Preferably, the drying aid is added to the polymer dispersion before drying. The drying agent can be used both as a solid or preferably as a solution, For example, as an aqueous-alcoholic solution or in particular as an aqueous solution, are added to the dispersion. It is also possible to use some of the possible drying assistants during the preparation of the aqueous polymer dispersion as protective colloid (see above). Preferred drying aids are arylsulfonic acid-formaldehyde condensation products and salts thereof, preferably the substances described in WO 98/03577.

Further can be the drying of the polymer dispersion during the Drying process add an anti-caking agent (anti-caking). This is a finely divided inorganic oxide, for example a finely divided silica or a finely divided silicate, e.g. Talc. Preferably, the finely divided inorganic oxide has an average particle size in the range of 0.01 to 0.5 mm. Particularly preferred is finely divided silica with a mean particle size in the range from 0.01 to 0.5 mm, which is both hydrophilic and hydrophobic can be. The anticaking agent may be before or during the drying of the polymer dispersion be dosed. In another embodiment, the anti-caking agent is added in one for Solids suitable mixing device, such as a vibrator, wheelchair screw mixer or the like, to the polymer powder.

Provided he wishes, Will you the anticaking agent in an amount of 0.5 to 15 wt .-% and preferably in an amount of 2 to 12 wt .-%, based on the polymer powder (or to the sum of polymer + drying aid in the aqueous Polymerisatdispersion), use.

For a sufficient Strength of the solidified according to the invention Soil it has proved to be advantageous when the polymer in an amount of at least 0.2% by weight and especially at least 0.5 wt .-%, based on the solid components of the soil material starts. With such small amounts are already good strength achieved, so that advantageously not more than 6 wt .-% and in particular not more than 4% by weight of polymer on the solid components of the soil material.

When Cement basically come all cements and mixtures of different cements which is the early strength required above according to DIN EN 196-1 and preferably after 12 h, a strength of at least 40% and in particular of at least 45% of the final strength, or after 24 h an early strength of at least 40%, preferably at least 50% and in particular at least 60% of the ultimate strength (each at 20 ° C). Suitable are also cements that have the above-required water binding capacity and in particular capable of containing water in an amount of at least 60 wt .-% and in particular at least 70 wt .-% of its own weight to bind. The water binding capacity of cement refers to both the physical (in form of crystal water) as well as the chemically bound water and let yourself in a conventional manner via Hydration equations for calculate every cement of known composition.

Without to be bound by a theory, one assumes that in these Cement types, the film formation of the polymer by the crystal growth when setting the cement is not or not to a significant extent disturbed and so on for Solidification with polymers characteristic elasticity of the solidified Guaranteed soil material remains. At the same time, due to its ability to To bind water, to promote strength building. In addition, the leads Presence of these types of Ze, especially when using low Polymerisat, to an increased Strength compared to the sole use of polymer or Cement.

Suitable cements with a water-binding capacity of at least 50% are in particular those cements with an increased content of aluminum oxide, which are usually in these cements at least 25 wt .-%, in particular at least 30 wt .-% and in particular at least 35 wt .-%, respectively as Al ₂ O ₃ . is. The upper limit of the alumina content is of minor importance for the effect according to the invention and may be up to 80% by weight or more. Normally, the aluminum oxide in these cements is predominantly in the form of calcium aluminates, such as CaAl ₂ O ₄ , Ca ₂ Al ₂ O ₅ , Ca ₃ Al ₂ O ₆ , Ca ₁₂ Al ₁₄ O ₃₃ , Ca ₂ Al ₂ O ₅ · SiO ₂ or Ca ₄ Al ₂ O.Fe ₂ O ₃ . Such cements are referred to as alumina cements due to their high aluminum oxide content.

The term "alumina cement" is familiar to the person skilled in the art, for example from Römpp Chemilexikon, 9th edition, Cement Suitable clay cements are described extensively in the literature, for example in Betoniek 11/8, 1998, pp. 1-8, cement-lime gypsum 9/1993, pp 560-566 and in DE-A 43 30 595, DE-A 197 27 979 and DE 100 05 221 , Such types of cement are commercially available under the name "alumina cement" or "high-alumina cement", for example from Heidelberger Zement AG or Heidelberger Calcium Alumi nates, Ardex GmbH, Dyckerhoff AG and Lafarge Calcium Aluminates Inc. In a preferred embodiment, a cementitious material is used which contains 25 to 80% by weight and in particular 30 to 60% by weight of aluminum oxide.

Cement types with a high early strength are known to those skilled in the art under the name rapid cement and are described in detail in the literature, for example in DE 4242107 . DE 196 33 447 . EP 211 365 . EP 1288175 , WO 92/12100 and WO 92/12103. Fast cements are commercially available under this name, for example from the companies Heidelberger cement AG, Heidelberger Calcium Aluminates, Ardex GmbH, Dyckerhoff AG and Lafarge Calcium Aluminates Inc.

Quick cements are, for example, the previously described Calciumaluminatreichen alumina or alumina cements and various cements based on calcium silicate cement, especially based on Portland cement clinker, the small amounts, usually 0.1 to 5 wt .-%, in particular 0.5 to 4 wt % of an organic or inorganic accelerating agent, for example by promoting the hydration of the calcium silicates or by increasing the OH ^- ion concentration, thereby providing early strength. An overview of means for accelerating the hardening, which are often referred to as setting accelerator, and an explanation of their mode of action can be found in H. Reul, Handbook of Construction Chemistry, Verlag für Chemische Industrie, H. Ziolkowsky KG, Augsburg 1991, chapter 1.3.6 , Pp. 158-180, the disclosure of which is hereby incorporated by reference. The setting accelerators are, for example, compounds which donate carbonation, for example alkali metal carbonates and bicarbonates, such as sodium or potassium carbonate, and sodium bicarbonates, reactive silicates, such as waterglass, and reactive aluminates, for example alkali metal and alkaline earth metal aluminates, in particular sodium aluminate and tricalcium aluminate, and calcium hydroxide.

Of the inventive success is also achieved with cement mixtures, in addition to a quick cement also a low early strength cement, e.g. conventional Contain silica cement such as Portland cement, as well as these mixtures a high early strength exhibit. In these mixtures, even small amounts of at least 10% by weight, advantageously at least 20% by weight Quick cement or alumina cement, the required early strength to ensure and thus the success of the invention to achieve. Accordingly, the invention also relates to such methods, in which as cement component a quick cement or a Mixture of a quick cement with a conventional cement with low early strength used, e.g. a conventional silica cement such as Portland cement, wherein the cement used at least 10 wt .-%, preferably at least 20% by weight of a quick-setting cement, for example one Quick-setting cement based on an alumina cement or a silicate cement, includes. If in the process according to the invention a mixture of different cement constituents is used, can these together or separately, i. successively in the to be solidified Ground to be incorporated.

• a) Substanzen, welche schwerlösliche Calciumsalze oder Calciumkomplexe bilden können, wie Natrium- und Kaliumphosphate und -polyphosphate wie Tetrakaliumpyrophosphat, Tetranatriumpyrophosphat und Natriumhexametaphosphat, Natrium, Natrium- und Kaliumphosphonate, Ammoniumphosphate und -phosphonate, Borsäure, Alkaliborate, wasserlösliche Silikofluoride wie Magnesiumhexafluorosilikat, (Poly)Hydroxy(poly)carbonsäuren wie Weinsäure, Gluconsäure und dessen Lacton, Heptonsäure, Citronensäure, Gallussäure, Äpfelsäure, Salicylsäure, 2,4,6-Trihydroxybenzoesäure, weiterhin Mono- und Disaccharide wie Saccharose, Glucose, Fructose, weiterhin Pyrogallol, Ligninsulfonat
• b) Kolloidbildner, wie Methylcellulose, Carboxymethylcellulose, Casein und Dextrin; Komplexbildner wie
• c) Komplexbildner wie Ethylendiamintetraacetat sowie
• d) Zinkoxid und Bleioxid.

In order to achieve a sufficient processing margin, one will usually use the rapid cement or mixture of quick cement with a low early strength cement together with a setting retarder (retarder) to push out the beginning of the solidification process of the cement paste, so the time within which the Cement can be processed to increase (non-processing time). An overview of retardants and an explanation of their mode of action can be found in H. Reul, Handbuch der Bauchemie, Verlag für Chemische Industrie, H. Ziolkowsky KG, Augsburg 1991, chapter 1.3.5. Pp. 123-157, the disclosure of which is hereby incorporated by reference. Examples of retarders are:

• a) substances which can form sparingly soluble calcium salts or calcium complexes, such as sodium and potassium phosphates and polyphosphates such as tetrapotassium pyrophosphate, tetrasodium pyrophosphate and sodium hexametaphosphate, sodium, sodium and potassium phosphonates, ammonium phosphates and phosphonates, boric acid, alkali borates, water-soluble silicofluorides such as magnesium hexafluorosilicate, (Poly ) Hydroxy (poly) carboxylic acids such as tartaric acid, gluconic acid and its lactone, heptonic acid, citric acid, gallic acid, malic acid, salicylic acid, 2,4,6-trihydroxybenzoic acid, furthermore mono- and disaccharides such as sucrose, glucose, fructose, furthermore pyrogallol, lignosulfonate
• b) colloid formers such as methylcellulose, carboxymethylcellulose, casein and dextrin; Complexing agents like
• c) complexing agents such as ethylenediaminetetraacetate and
• d) zinc oxide and lead oxide.

As a rule, the setting retarder will be used in an amount such that a processing-free period of preferably at least 15 minutes and in particular at least 30 minutes, for example 15 minutes to 5 hours and in particular 30 minutes. until 3 h and especially 1 to 2 h is reached. The amounts of retardants required for this naturally depend on the type of setting retarder used and can from Expert in routine experiments and based on manufacturer's instructions and guide values, as indicated in the literature cited here are easily determined. Usually, the amounts required for this purpose in the range of 0.01 to 5 wt .-% and in particular in the range of 0.1 to 2 wt .-%, based on the cement. By using a setting retarder in the amounts customary for this purpose, the early strength is usually not lowered or not significantly reduced. For incorporation in the sand-containing soil materials, the setting retarder can be premixed with the cement or be mixed separately from this in the soil material. The former procedure is preferred.

to Achieving the desired Soil resistance has proven to be advantageous when using the cement Z in an amount of at least 0.5 wt .-%, in particular at least 1% by weight, more preferably more than 2% by weight, e.g. at least 2.1 wt .-% and most preferably at least 2.5 wt .-%, based on the solid components of the soil material. Preferably will be no more than 8 wt .-% of cement Z, based on the solid Components of the soil material, insert.

Farther You can also use small amounts of other, different from cement hydraulic Incorporate binders in the soil, such as quicklime or Plaster. These materials are preferably not or only in Amounts of up to 10% by weight, in particular not more than 5% by weight and especially not more than 2% by weight, based on the soil material deploy.

The Incorporation of the polymer i) and the cement ii) can in itself known manner, e.g. to those in the art, e.g. WO 02/48068 done methods described. Usually one gets the incorporation so make that one as possible even distribution achieved in the soil material. For this purpose, the polymer i. and the cement ii. simultaneously, e.g. as a mixture or successively incorporated, the latter approach being preferred. This has proven particularly useful when you first the Cement and then the polymer incorporated into the soil. Farther It may be beneficial if the soil material during incorporation of cement and polymer contains a certain amount of water, as a result the mixing is facilitated. This water can already be in the be included to verfesti ing soil material and / or with the Polymer and / or cement the soil material during incorporation supplied become. in principle but it is also possible Water only after the incorporation of cement and polymer to work into the soil. Preferably, the soil material during the Incorporation of polymer and cement at least 0.1 wt .-%, in particular 0.1 to 30 wt .-%, particularly preferably 0.1 to 20 wt .-% and especially 0.1 to 15 wt .-% water, based on the solid soil components. The water content in the soil materials can be adjusted to the desired Values, e.g. by adding with the ingredients to be incorporated according to the invention or by drying or adding water to the soil material become.

In Advantageously, the polymer is worked in the form of an aqueous Polymer dispersion, so that at least a part of the incorporation contained in the soil material water from the aqueous polymer dispersion. As already explained above The polymer can also be used in the form of a powder. It has shown that the water in the ground is often already is sufficient to ensure a filming of the polymer. If the water content is <0.1 wt .-% and the Polymer is to be incorporated in the form of a powder has it works well first Cement and polymer into the soil and then the water content adjust by adding water.

The Incorporation of cement and polymer in the soil material can by usual Mixing techniques for mixing finely divided solids or for incorporation of liquids in solids. For this one can, for example, to be fastened Dig out or dig out the soil, if necessary, the soil thus obtained crush, mix with polymer and cement and mix, until the polymer and cement are evenly distributed in the excavation are where, if necessary, the water content in the mixing the mixture to a value in the range of 1 to 30 wt .-%, preferably 2 to 20 wt .-% and in particular 3 to 15 wt .-% and adjusts the so reaps mixture. Alternatively, you can do that that you apply cement and polymer on the soil material and subsequently underpinned, for example, milling.

Possibly may be the incorporation of the ingredients cement and polymer compacting the soil material, e.g. by pounding or rolling connect.

The solidified according to the invention soil materials are characterized by a curing phase, which is depending on the ambient temperature and water content of the soil material in the range of 1 to 48 h, by significantly increased Biegezug- and compressive strengths and by increased elasticity compared to unmodifizier Tonformkörpern. Advantageously, a drying step to temperatures above ambient temperature is no more necessary than a removal of the water contained in the soil. Therefore, the method according to the invention permits solidification of the soil at any depth below the soil surface, eg at a depth of more than 10 cm, often more than 0.2 m and especially down to depths of more than 0.5 or even more than 1 m to reach. The shrinkage usually observed during the drying of moist masses based on clastic sediments is as a rule not adversely or only negligibly influenced in the process according to the invention.

typical Application areas for the inventive method are constructive construction measures, in which structures are built from soil materials, for example the consolidation of road substructures, dam and dike construction, the use in landfill gaskets or in the sealing and attachment of surfaces, the mechanical stress are exposed, like embankments, Driveways or parking areas.

Farther can from the soil material after incorporation of the ingredients if desired Moldings, in particular building blocks or bricks are formed. suitable Process for the production of shaped bodies from mineral masses As sand-containing soil materials are known in the art and can in be used analogously for the preparation of such moldings.

To the Solidification of the moldings These are usually left to themselves in the air or on a temperature of up to 150 ° C, preferably up to 120 ° C heat.

The The following examples are intended to illustrate the invention but are not restrictive to understand.

Starting Materials:

polymer:

The polymer which was prepared according to Example ED4 on page 13f. of the EP 1182179 A2 prepared emulsion polymer of styrene, 2-ethylhexyl acrylate, n-butyl acrylate and 2-hydroxyethyl acrylate used. The polymer has a glass transition temperature of -31 ° C. The polymer is thus film-forming at 0 ° C.

Cement:

Cement A: alumina cement Istra 50 of the Heidelberger calcium aluminates

• Chemical analysis: CaO: 37-40 wt.% Al ₂ O ₃ : 50-53 wt.%, SiO ₂ : 3-6 wt.%, Fe ₂ O ₃ : 1-3 wt.%, SO ₃ : <0.4% by weight.
• Water-binding capacity typically 60-80 Wt .-%
• Main components CA, C ₂ AS
• Physical properties: Bulk weight: 1.00 kg // dm ³ Specific gravity: 3.0-3.1 kg // dm ³ Specific surface area: 3300-3600 cm ³ / g Early strength after 12 h at 20 ° C (in standard mortar after DIN 196): 70 N / m ² final strength after 28 d at 20 ° C (in standard mortar according to DIN 196): 95 N / m ²

Cement B: Quick cement Chronolith ^® one of the company Heidelberger Cement AG.

• Chemical analysis: CaO: 59.9 wt.% Al ₂ O ₃ : 7.8 wt.%, SiO ₂ : 18.6 wt.%, Fe ₂ O ₃ : 3.0 wt.%, MgO : 2.2% by weight, K ₂ O: 1.1% by weight, SO ₃ : 3.7% by weight.
• Main components C ₃ S, C ₂ S
• Physical properties: Bulk weight: 1.0-1.2 kg // dm ³ Specific gravity: 3.00-3.02 kg // dm ³ Specific surface area: 5200-5800 cm ³ / g
• Early strength after 12 h at 20 ° C (in standard mortar according to DIN 196): 20.0 N / m ²
• Ultimate strength after 28 d at 20 ° C (in standard mortar according to DIN 196): 38.0 N / m ²

Cement C: Portland cement: CEM I 32.5 R of Heidelberg cement Germany

Flooring:

When Soil material served a commercial Spülsand based on quartz sand with a particle size in the range of 0.1 to 0.6 mm (90% value: silt content <1%, Fine gravel fraction <1%).

Production of a test specimen a solidified according to the invention Soil material and testing the mechanical properties of the test specimen

Of the Sand was in a plastic cup while stirring with a commercial Kitchen kneading machine with the desired Amount of cement and polymer added in the form of an aqueous dispersion and subsequently 2 min. touched. The amounts of starting materials are given in Table 1. Then it became The treated sand in steel molds with the dimensions 160 mm × 40 mm × 40 mm (cementless specimen) or 160 mm × 40 mm × 15 mm (cementitious specimen) placed in layers, compacted, covered with foil and then 7 d left at room temperature. The thus obtained molded article was disengaged and subjected directly to a bending tensile test.

For this the test specimen was opened two parallel steel bars with a diameter of 10 mm and a distance of 100 mm (cement-containing propene body) or 75 mm (for cementless specimens) placed. Now is a pressure roller in the middle and parallel to the steel bars made of aluminum with a diameter of 10 mm placed on the specimen and associated with a debit stamp. This stamp comes with a settlement dial to determine the settlement in the direction of force connected. Now the load will gradually increase until the breakage of the specimen increased and for every step of setting and strength determined. From the won Values can Elongation at break ε and breaking stress σ in a conventional manner be determined. The results are shown in Table 1.

Determination of abrasion resistance

to Determination of abrasion resistance was the sample body 2 d in water at 25 ° C stored. Subsequently was qualitatively scratched with a wooden stick the abrasion resistance determined, and assessed qualitatively according to a grading scale from 1 to 6, where 1 means no abrasion and 6s a lot of abrasion. Please complete. The Results are summarized in Table 1.

Table 1

Similar results are obtained if butadiene dispersion styrene having a glass transition temperature T _G = -10 ° C and an MFT of 0 ° C used in place of the above-described polymer dispersion, a commercially available (Styrofan ^® LD417 of BASF Aktiengesellschaft).

Claims (11)

Method for consolidating sand-containing soil materials, including the incorporation of i) at least one finely divided, insoluble in water film-forming polymer P having a minimum film-forming temperature MFT ≤ 30 ° C in one Amount of 0.1 to 10 wt .-%, based on the solid constituents of sandy soil material, and ii) at least one cement in an amount of 0.5 to 10 wt .-%, based on the solid constituents the sand-containing soil material, wherein the cement by a water binding capacity of at least 50 wt .-% and / or by an early strength according to DIN EN 196-1 at 20 ° C characterized after 12 h of at least 30% of the final strength, in the sandy soil materials. The method of claim 1, wherein the cement is at least 10 wt .-%, based on the total amount of cement, at least one Quick cement includes. The method of claim 1 or 2, wherein the cement at least 10% by weight, based on the total amount of cement, of alumina cement includes. The method of claim 2, wherein the cement is at least 10% by weight, based on the total amount of cement, of a rapid cement based on calcium silicate cement. A method according to any one of claims 2 to 4, wherein In addition, a retarding agent is incorporated in the sand-containing soil. Method according to one of the preceding claims, wherein the finely divided, water-insoluble polymer P through radical, watery Emulsion Polymerization of ethylenically unsaturated monomers available Polymer is. The method of claim 6, wherein the finely divided Polymer selected is among copolymers of styrene with butadiene, copolymers of styrene with alkyl acrylates, homopolymers and copolymers of alkyl (meth) acrylates, Homo- and copolymers of vinyl esters of aliphatic carboxylic acids and copolymers of vinyl esters aliphatic carboxylic acids with olefins and / or alkyl (meth) acrylates. Method according to one of the preceding claims, wherein the finely divided, water-insoluble polymer P in the form an aqueous Polymer dispersion incorporated into the sandy soil. Method according to one of the preceding claims, wherein the sand-containing soil does not contain more than 10% by weight of constituents a grain size <0.002 mm. Method according to one of the preceding claims, wherein you first the cement ii) and then the polymer i) incorporated into the sandy soil. Method according to one of the preceding claims, wherein the floor during or after incorporation of ingredients i) and ii) water in one Amount of 0.1 to 30 wt .-%, based on the solid constituents of the soil.