WO2009118376A1

WO2009118376A1 - Method for base or foundation reinforcement

Info

Publication number: WO2009118376A1
Application number: PCT/EP2009/053582
Authority: WO
Inventors: Axel Siegner
Original assignee: Poligate Limited
Priority date: 2008-03-28
Filing date: 2009-03-26
Publication date: 2009-10-01
Also published as: RU2010143892A; EP2279232A1; DE102008016325A1; AP2010005376A0; RU2503768C2

Abstract

The invention relates to a method for reinforcing bases and foundations, in which a base or foundation reinforcer comprising a latex polymer (A), a thickener (B), a defoamer (C) and at least one salt or hydroxide (D) of an alkali metal or alkaline earth metal and optionally water, optionally after mixing with water and optionally together with cement and/or fillers, is incorporated into the base or the foundation while mixing with the base or the foundation.

Description

Method for soil or foundation consolidation

description

The invention relates to methods for soil or foundation consolidation and the use of the solidifiers for consolidating soil or soil containing materials.

In the manufacture of roads, a soil layer is typically removed first, and after flattening the surface, a gravel support layer is applied, followed by an asphalt base course, an asphalt binder course and an asphalt face course. The gravel support layer often has a thickness of 50 to 70 cm, and thus has the largest thickness of the entire coating.

For the preparation of foundations, the soil is usually also excavated and filled with a straightening with the foundation material.

These known methods lead to high construction costs, since a soil replacement must be carried out and also costly material deliveries, earthworks and disposal of soils and numerous transports are necessary. Typically, old soil must be removed and stored in landfills. For some applications, the compressive strengths are still insufficient, resulting in a lack of stability of the consolidated floors or foundations.

WO 97/23433 relates to dispersions and their use in concrete mixtures.

DE-A-1 571 449 relates to mortar compositions which, besides Portland cement, filler and water, also contain a polymer emulsion and a cellulose derivative.

US 3,943,078 relates to a soil treatment composition containing a synthetic latex material, hydroxyethyl cellulose, metal salts and powdered citric acid.

The object of the present invention is to provide a method for soil or foundation consolidation, which allows to carry out without removal of the old soil and its disposal in a very simple way earth-engineering measures for soil improvement, soil consolidation and soil stabilization. The object is achieved by a method for strengthening of soils and foundations, in which a soil or Bodenungsfestfestiger, optionally after mixing with water and optionally together with cement and / or fillers in the ground or the foundation with mixing with the ground or Incorporated foundation. It may be at the bottom of the ground of a traffic area, z. As a road, a path or a, z. B. paved, square act. In general, any surface can be treated according to the invention.

Typically, the soil and Bodenungsfestfestiger invention is incorporated with a cutter in the soil to be consolidated by milling. This eliminates the usually necessary and costly replacement of the resulting soil.

For example, the liquid composition of the invention is over a

Microprocessor-controlled pump sprayed into the catchment area of a milling machine and mixed by the tiller with the ground or soil. In this case, for example, cement or a (further) filler can be pre-scattered on the ground or the foundation and also introduced into the ground with the milling cutter. In the remediation of soil surfaces, such as roads, the entire road surface layer can be mixed with the miller with the addition of the inventive solidifier. A removal of individual

Layers can be avoided.

In accordance with the invention, soil or foundation strengtheners or corresponding agents are used which comprise a latex polymer A, a thickener B, a defoamer C and at least one salt or hydroxide D of an alkali metal or alkaline earth metal and optionally water.

It has been found according to the invention that soil or foundation consolidators comprising a latex polymer A, a thickener B, a defoamer C and at least one salt or hydroxide D of an alkali or alkaline earth metal can be incorporated into existing soil after incorporation into water with mixing, wherein after a short setting time already sets the solidifying effect. For example, the existing soil is simply milled under entry of the invention Boden- or Fundamentver festigers and subsequently tied.

The solidifier used according to the invention is a polymer-based, preferably water-soluble, environmentally neutral and non-toxic additive for use in soil-engineering measures for soil improvement, soil stabilization and soil stabilization with hydraulic binders.

The solidifier according to the invention can be present, for example, in free-flowing solid form and 0.1 to 50 wt .-%, preferably 0.5 to 25 wt .-% of component A, 0.05 to 5 wt .-%, preferably 0.1 to 2 wt .-% of component B,

0 or 0.05 to 5 wt .-%, preferably 0 or 0.1 to 2 wt .-% of the component C and 0.01 to 10 wt .-%, preferably 0.05 to 5 wt .-% of the component D included,

wherein the total amount of components A to D is 100% by weight. The solidifier is preferably present in powder, flake or granular form. Other possible flowable solid forms are known to those skilled in the art.

Component C may be present or absent.

Alternatively, the solidifying agent may be in a flowable liquid form and may contain 3 to 95% by weight, preferably 30 to 80% by weight of a mixture as described above in 5 to 97% by weight, preferably 20 to 70% by weight. Contain water.

The solidifying agent in flowable solid form can be made into the flowable liquid form simply by incorporation in water and dissolving or dispersing therein.

The flowable liquid form can be introduced directly into the soil for incorporation, while the flowable solid form allows for simplified storage and transportation. The introduction into water can be done immediately before use.

All ingredients of the solidifier can be used in solid or dissolved / dispersed form. For example, the latex polymer A may be used in the form of a powder or a latex solution. An aqueous latex solution preferably has one

Concentration of 30 to 60 wt .-%. In the ready-to-use composition, the proportion of the latex is preferably 0.5 to 20% by weight, particularly preferably 1 to

10% by weight. The proportion of the thickener B is preferably 0.1 to 5 wt .-%, particularly preferably 0.1 to 2 wt .-%. The proportion of component D is preferably 0.01 to 10 wt .-%, particularly preferably 0.05 to 5 wt .-%.

The proportion of antifoam C, if it is used as an emulsion, is preferably 0.05 to 5 wt .-%, particularly preferably 0.1 to 2 wt .-%. As latex polymer A, any suitable latex polymers which are soluble or dispersible in water can be used. The latex polymer A is preferably a styrene-butadiene latex (SBR), (meth) acrylate latex, ethylene-vinyl acetate latex, ethylene / propylene latex, ethylene / propylene-diene latex (EPDM), butadiene rubber. Acrylonitrile latex (NBR), silicone latex (SI), polybutadiene latex (BR), natural rubber latex or a mixture of two or more thereof. The latex can be uncrosslinked or crosslinked. It is also possible to use an uncrosslinked latex together with a crosslinking agent. In particular, chemical crosslinkers are included. The molecular weight of the polymer on which the latex is based can be freely selected within wide limits. Typically, the molecular weight is 300 to 1,000,000, preferably 500 to 100,000 g / mol (number average molecular weight as determined by gel permeation chromatography).

Particularly preferably, a crosslinked latex or a latex is used together with a crosslinking agent. Suitable latexes are available commercially and can be obtained from a variety of sources. Particular preference is given to using acrylate, styrene-butadiene or ethylene-vinyl acetate latexes.

The latexes are generally colloidal dispersions of polymers in aqueous media which have low viscosities even at high polymer concentrations. Synthetic latexes are typically prepared by emulsion polymerization of suitable monomers or by dispersing polymers in one

Dispersants produced. The latices may contain additives such as protective colloids,

Stabilizers, pigments and vulcanization aids. In addition, the thickening agents described below may be included.

As thickening agent B, any suitable thickening agents can be used. Thickening agents, which can also be referred to as swelling agents, are generally organic, high molecular weight substances which absorb liquids, especially water, swelling, and eventually pass into viscous true or colloidal solutions. The thickeners serve to increase the viscosity of the solidifiers according to the invention. Any suitable thickening agent can be used according to the invention.

For example, organic natural thickening agents such as agar-agar, carrageenan, tragacanth, gum arabic, alginates, pectins, polyoses, guar flour, locust bean gum, starch, dextrins, gelatin or casein can be used. It is also possible to use organic, modified natural substances such as carboxymethylcellulose and other cellulose ethers, hydroxyethyl and propylcellulose as well as core flour ethers.

It is also possible to use organic, fully synthetic thickeners, such as polyacrylic and polymethacrylic compounds, vinyl polymers, polycarboxylic acids, polyethers, polyimines or polyamines.

Further, it is possible that inorganic thickening agents such as polysilicic acids, clay minerals such as montmorillonites, zeolites or silicas are used.

Preferably, a cellulose-based thickener is used. The thickener is particularly preferably selected from carboxymethylcellulose, cellulose ethers, hydroxyethylcellulose, hydroxypropylcellulose and mixtures of two or more thereof. In particular, methyl cellulose is used.

As component C defoamers according to the invention are also used. These are substances that form a closed film liquid-gaseous at the interface and thus allow the medium to be degassed to form the smallest surface and thus the lowest-energy state in a very short time by destroying the gas bubbles. The defoamers which destroy the foam which has already formed have, in principle, the same composition as the antifoaming agent which prevents foaming. These may be surfactants that displace the foaming agents from the interface without producing foam themselves, or products that increase the surface tension of the water, such as natural fats and oils or fatty alcohols. In many cases defoamers are used silicone-based. Glycol ethers such as polyethylene / propylene glycol ethers or mixed ethers may also be used, for example. Preferably, an antifoam emulsion is used according to the invention, as is commercially available.

As component D, at least one salt or hydroxide of an alkali metal or alkaline earth metal is used according to the invention. These are preferably sodium, magnesium and / or calcium compounds. In particular, the hydroxides or chlorides are used. Particular preference is given to using a combination of sodium hydroxide and calcium chloride. Based on the ready-to-use liquid composition, the proportion of the sodium hydroxide is preferably 0.01 to 0.15% by weight. The proportion of calcium chloride is preferably 0.5 to 5 wt .-%. - -

Sodium hydroxide and calcium hydroxide are used to adjust the pH and to stabilize the composition of the invention.

The solidifiers used erfϊndungsgemäß may also contain other conventional auxiliaries and additives.

The solidifiers used according to the invention can be prepared by simply mixing the starting materials. The powders of the starting materials can be mixed. It is also possible to mix aqueous solutions, emulsions or dispersions of the starting materials with one another in order to obtain an application-ready, flowable liquid composition.

The ground consolidators or foundation consolidators used according to the invention are used, if appropriate after mixing with water, for consolidating soil or soil, soil-containing materials such as mixtures of soil and road coverings or building materials, or foundation materials. According to one embodiment of the invention, the solidifier is not used in concrete or cement. Concrete or cement additives in the consolidation of soil are generally not critical.

In the method according to the invention, sampling of the soil is typically first carried out, so that soil mechanical laboratory investigations can be carried out. In addition, preliminary geotechnical investigations can be carried out, and for traffic areas, the loads and frequency of traffic can be determined. Furthermore, the climate can be determined, for example, the frequency of frost and the amount of rainfall. From this, the dosage of the cement can be determined, as well as the dosage of the inventive Festigers. After, for example, the soil has been pretreated by the leveler, grader and caterpillar, cement spreading and introduction of the solidifier according to the invention via a milling cutter can follow. Then, in turn, levelers, graders and caterpillar as well as roller can connect. Typically, then a sampling is carried out and the load capacity after setting is examined. This will ensure adequate quality assurance. Finally, for example, an asphalt application can take place in the usual way, it being possible to dispense with a layer of crushed aggregate.

Without being bound by theory, it is believed that the latex cross-links and, together with the emulsion, displaces capillary water from the ground or foundation. The thickener also binds water. Higher soil strengths and concrete strengths are achieved according to the invention by the admixture of very fine additives. In this case, silicate particles are preferably added during the production of high-strength concretes. These silicate particles are about 30 to 100 times smaller than the cement bodies (diameter in the micrometer range) and consist almost entirely of amorphous silicon dioxide. Due to their shape and size, the silicate particles are able to fill a portion of the pore space between the cement grains much better. Thus, the caused due to the dispersing effect of the superplasticizer structural compaction of the cement paste is again significantly increased, and it is achieved a higher density. In addition to cement hydration, a Putzolan secondary reaction occurs between the calcium hydroxide formed during cement hydration and the silicate particles. This calcium silicate hydrate is formed, which has a higher strength compared to the starting materials. According to the invention also the microstructure in the composite zone between cement and aggregate significantly improved by this approach. This improved association between aggregate and matrix by influencing the calcium and ettringite content contributes significantly to the increase in strength. According to the invention, these auxiliaries, based on cement, in an amount of 5 to 99 wt .-%, particularly preferably 10 to 50 wt .-%.

It is particularly preferred to add silicate particles which preferably have an average particle size in the range from 100 to 1000 nm.

The ratio of inventive solidifier to cement can be chosen freely within wide ranges. A proportion of solidifier (determined as dry mass), based on the cement, of 0.1 to 20 wt .-%, particularly preferably 0.3 to 10 wt .-% is preferred.

The use of the soil and Bodenungsfestigers invention is particularly advantageous for

Substructure and base course for state, federal highways and highways

Pedestrian and cycle paths with and without superstructure - forestry, forestry and farm roads

Parking spaces, storage and container areas with / without superstructure

site access

Renovation work, preparation of farm roads - o -

Gardening and landscaping

Stabilization of humus rich soils, (sewage) sludges and fly ashes - foundations in special civil engineering

runways

access roads

Attachment of gravel roads.

Significant advantages of the soil or Bodenungsfestfestiger invention are

- higher strength, fracture deformation, deformation modulus lower water absorption capacity lower water permeability and water penetration higher frost resistance and weather resistance better shrinkage behavior and no drying out - faster setting behavior

Setting in the case of organic constituents Setting in the case of pollutants in the soil

Bonding with fresh and salt water better processability and compactability - high durability.

In addition, the solidifier used in the invention is environmentally friendly and can even be used for setting and thus stabilizing contaminated soils. Even under the most difficult conditions, under which a road rehabilitation or a road construction of conventional type are no longer possible, the processing of the inventive solidifier can be done, for example, in frost.

The use of the method according to the invention leads to a significant reduction of

Construction costs by saving on expenses for soil replacement, transport, material supply, earthworks and soil disposal. The construction time can be up to

50% be lowered. A driving on the construction field is after a short time, typically two days, due to the fast setting process possible. Maintenance costs can be reduced while achieving much higher compressive strengths. Even with frost, the inventive method can be performed.

The invention also relates to the use of the soil or foundation consolidators as defined above, optionally after mixing with water, for consolidating soil or soil containing materials. These materials are preferably not cement, concrete or mortar, but soil or physical mixtures of soil with other materials, such as soil with stones, crushed stone or rock dust, or mixtures of soil with debris or road surfaces or substrates to which Road coverings are applied. Particularly preferably, the soil or Bodenungsfestfestiger be used in road or road construction or in the road or road restoration.

The invention is further illustrated by the following example.

composition

The following ingredients are mixed together with stirring, the amounts given being% by weight: 92.5% water, 0.4% cellulose, 2.0% calcium hydroxide, 5.0% aqueous 55% latex solution, 0.1 % Defoamer emulsion.

The composition can be used directly for soil consolidation by milling in soil.

Claims

claims

1. A method for consolidating soils and foundations, characterized in that one comprises a soil or Bodenungsfestfestiger containing a latex polymer A, a thickener B, a defoamer C and at least one salt or hydroxide D of an alkali or alkaline earth metal and optionally water, optionally after Mixing with water and possibly together with cement and / or fillers in the ground or the foundation incorporated with mixing with the ground or the foundation.

2. The method according to claim 1, characterized in that it is at the bottom of the ground of a traffic area, preferably a road, a path or a place.

3. The method according to claim 1 or 2, characterized in that the incorporation is done by milling with a milling cutter.

4. The method according to claim 3, characterized in that cement or a filler vorstrereut on the ground or the foundation and also with the cutter in the

Soil is introduced.

5. The method according to any one of claims 1 to 4, characterized in that the bottom or foundation Ver consolidator in flow capable solid form is present and

0.1 to 50% by weight of component A,

0.05 to 5 wt .-% of component B,

0 to 5 wt .-% of component C and

0.01 to 10 wt .-% of component D.

contains, wherein the total amount of components A to D gives 100 wt .-%.

6. The method according to any one of claims 1 to 5, characterized in that the soil or Bodenungsfestfestiger is in flowable liquid form and 3 to 95 wt .-% of a mixture of 0.1 to 50 wt .-% of component A, 0.05 to 5 wt .-% of component B, 0 to 5 wt .-% of component C and

0.01 to 10% by weight of component D, the total amount of components A to D being 100% by weight

in 5 to 97 wt .-% water.

7. The method according to any one of claims 1 to 6, characterized in that the latex polymer A is a styrene-butadiene latex, (meth) acrylate latex, ethylene-vinyl acetate latex, ethylene / propylene latex, ethylene / propylene dimer Latex,

Butadiene-acrylonitrile latex, silicone latex, polybutadiene latex, natural rubber latex, or mixture of two or more thereof.

8. The method according to any one of claims 1 to 7, characterized in that a thickening agent is used based on cellulose.

9. The method according to claim 8, characterized in that the thickener is selected from carboxymethylcellulose, cellulose ethers, hydroxyethylcellulose hydroxy xylpropylcellulose and mixtures of two or more thereof.

10. The method according to any one of claims 1 to 9, characterized in that a defoamer emulsion is used as antifoam.

11. Use of the soil or Bodenungsfestfestiger, as defined in any one of claims 1 or 5 to 10, optionally after mixing with water, for

Solidifying soil or soil containing materials.