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Title:
METHOD FOR COATING A MATRIX WITH FIRE, WATER AND FROST-PROOF BARRIER LAYER AS WELL AS LAYER PREPARED BY THE METHOD
Document Type and Number:
WIPO Patent Application WO/2008/004874
Kind Code:
A1
Abstract:
Method for coating a matrix with a fire, water and frost-proof barrier as well as the coating thus manufactured. The matrix, which can be a wall in a tunnel, is sprayed-on a first layer of a settable material composition comprising micronized aplite. Then at least one layer of fibre reinforcement is applied on top of the first layer whereafter another layer of sprayable settable material composition is sprayed-on. This third layer comprises aplite, anhydrite, slag and calcite. Both the first and the third layer may also contain conventional hydraulic cements. The applied layers are allowed to set to a hard material.

Inventors:
EIDE HALLVAR (NO)
GODOEY RUNE (NO)
SAASEN ARILD (NO)
Application Number:
PCT/NO2007/000202
Publication Date:
January 10, 2008
Filing Date:
June 11, 2007
Export Citation:
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Assignee:
EIDE HALLVAR (NO)
GODOEY RUNE (NO)
SAASEN ARILD (NO)
International Classes:
E21F5/00; A62C3/00; E21B35/00
Domestic Patent References:
WO2006115415A12006-11-02
WO2002028799A12002-04-11
Other References:
See also references of EP 2032799A4
Attorney, Agent or Firm:
CURO AS (Heimdal, NO)
Download PDF:
Claims:

Claims

1. Method of covering a matrix with a fire, water and frost-proof barrier, characterized in spraying the matrix a first layer of a settable material composition comprising micronized aplite, thereafter covering the formed layer with at least one layer of fibre reinforcement and thereafter spray-coating a layer of settable material composition comprising aplite, anhydrite, slag, and calcite.

2. Method as claimed in claim 1 , characterized in that per se conventional spraying equipment is used for spray coating of the first and third layer.

3. Method as claimed in claim 1 , characterized in that the first layer is applied with a thickness between 50 and 150 mm.

4. Method as claimed in claim 1 , characterized in that the first layer when applied has a water content in the range 40-50 % by weight of the of the dry substance.

5. Method as claimed in claim 1 , characterized in that the micronized aplite mainly is of a particle size in the range 150-170 μm. 6. Method as claimed in claim 1 , characterized in that the micronized aplite has a quartz content of at least 68 % by weight and more preferred at least 75 % by weight of the aplite.

7. Method as claimed in claim 1 , characterized in that the micronized aplite is present as the sole bonding agent in the first layer ad that the reaction that causes the layer to set is controlled by adjusting pH of the settable material composition to a value lower than 7, preferably lower than 6, and more preferred lower than 5.

8. Method as claimed in claim 1 , characterized in that the first layer also comprises a hydraulic cement such as a Portland cements, pozzolan cement, gypsum cement, alumina cement, silica cement or slag cement.

9. Method as claimed in claim 1 , characterized in that the hydraulic cement is present in the first layer in an amount in the range 15-35 % by weight of the total weight of cement material (aplite + other cement material).

10. Method as claimed in claim 1 , characterized in that discrete carbon fibres are present in the settable material composition of the first layer.

11. Method as claimed in claim 1, characterized in that micro-spheres with a diameter in the range 5 - 200 μm are present in the settable material composition of the first layer.

12. Method as claimed in claim 1 , characterized in that the reinforcement layer comprises fibres which are non-corrosive even in an acid environment.

13. Method as claimed in claim 12, characterized in that the fibres are carbon fibres.

14. Method as claimed in claim 12 or 13, characterized in that the fibres are arranged in a structured form such as but not limited to, woven, knitted, or braided form.

15. Method as claimed in claim 14, characterized in that the carbon fibres have a diameter in the range 1-15 μm, more preferred 3-10 μm and most preferred 6-8 μm. 16. Method as claimed in claim 1 , characterized in that the third layer is applied with a thickness in the range 50 - 150 mm.

17. Method as claimed in claim 1 , characterized in that anhydrite is present in the third layer in an amount in the range 2-5 % by weight of the dry substance.

18. Method as claimed in claim 1 or 17, characterized in that the particle size of the anhydrite mainly is in the range 0.1 to 5 mm.

19. Method as claimed in claim 1, characterized in that calcite is present in an amount in the range 2-5 % by weight of the dry substance.

20. Method as claimed in claim 1 or 19, characterized in that the particle size of calcite mainly is in the range 01 to 5 mm. 21. Method as claimed in claim 1 , characterized in that the micronized aplite is present as the sole bonding agent in the third layer ad that the reaction that causes the layer to set is controlled y adjusting pH of the settable material composition to a value lower than 7.

22. Method as claimed in claim 1 , characterized in that micro-spheres with a diameter in the range from about 5 μm to about 200 μm are included in the settable material composition of the third layer.

23. Method as claimed in claim 1 , characterized in that the matrix that is covered by the first layer is an internal mountain wall which has been exposed by a technique chosen among drilling and blasting.

24. Method as claimed in claim 23, characterized in that the internal mountain wall comprises wall and ceiling of a tunnel.

25. Coating for internal surfaces in tunnels, characterized in comprising a first layer of a settable material composition comprising micronized aplite, a second layer which is a reinforcement layer, and a third layer formed from a settable ass comprising aplite, anhydrite, slag and calcite. ^ 26. Coating for internal surfaces in runnels, characterized in being formed by means of a method according to any one of the claims 1-24 and subsequent curing or setting.

27. Coating as claimed in claim 25 or 26, characterized in that the first layer comprises at least 65 % by weight of micronized aplite.

28. Coating as claimed in claim 25 or 26, characterized in that the third layer comprises at least 75 % by weight of micronized aplite and up to 25 % by weight of an hydraulic cement, calculated of the dry substance of cement components.

29. Coating as claimed in claim 21 or 22, characterized in that at least 80 % of the aplite has a particle size les than 200 μm.

30. Coating as claimed in claim 21 or 22, characterized in that at least 50 % of the aplite has a particle size less than about 100 micron.

31. Coating as claimed in claim 21 or 22, characterized in that the aplite has a silicate (quartz) content o at least 68 % by weight and ore preferred at least 75 %. 32. Coating as claimed in claim 21 or 22, characterized in that at least one of the layers chosen among first and third layer has a content of quartz also from other sources than aplite.

33. Coating as claimed in claim 21 or 22, characterized in that aplite granules as an aggregate has been added to at least one layer chosen among first and third layer. 34. Coating as claimed in claim 21 or 22, characterized in that at least one of the following materials are used as a aggregate: sand, gravel, anhydrite, glass, foamed glass.

35. Coating as claimed in claim 21 or 22, characterized in that the coating during setting shrinks less than 3 %, preferably less than 1.5 % and most preferred less than 0.7 %.

Description:

Method for coating a matrix with fire, water and frost proof barrier layer as well as layer prepared by the method

Background

In a number of connections it is desirable to coat a surface or matrix with a coating that is water, frost, and fire-proof and in some connections rigid law regulations apply to use of such coating.

With regard to tunnels, especially road tunnels, there have been a number of severe fire accidents in recent years which has led to a strong focus on choice of materials used in such environments. With regard to applications techniques for such kind of coatings, it can vary from use of prefabricated elements to spraying-on of settable compositions of mortar and optional additions. An advantage with the prefabricated elements is that the composition of the elements is simpler to control when it is not required that any component be sprayable. In addition it is not necessary to use water in any component and it is simper to find compositions that satisfies requirements related to fire, water and frost safety.

Sprayable compositions have the advantage that they can e sprayed directly onto an uneven surface without need for smoothing or lathing prior to mounting of elements with a certain form and size. Transport is also simpler since it is bulk and not in the form of large elements requiring mechanical handling prior to and during mounting. The disadvantage with sprayable compositions has until now been that it has not been possible to make such compositions comply with the demands to safety that exists for the most relevant fields of use.

Objects

It is thus an object of the present invention to provide a method for making or preparing coatings on a matrix, such as a mountain wall, like a tunnel wall. The coating should have good safety in relation to fire and good properties in relation to water and frost. It is furthermore an object to be ale to make or prepare the coating by means which are inexpensive and flexible and which do not require extensive adaptations or "tailoring" for each individual application. The present invention

According to a first aspect the present invention provides a method as defined by claim 1.

According to a second aspect the present invention provides a coating as defined by claim 25.

Preferred, non-limiting embodiments of the invention are disclosed by the dependent claims.

By "micronized" is understood a powdery form in which the particle size is in the range up to about 200 μm (micron). When it is stated that a certain compound, like aplite, is mainly within a defined particle size range, it is to be understood that at least 50 % by weight of the particles is in that range and preferably at least 80 %.

Aplite is a granite rock mainly consisting of quartz and feldspar. It occurs in different continents and is available in different qualities. Aplite is e.g. found in Montpellier, Virginia, USA, Owens Valley, California, USA, Finnvolldalen in Norway, in Toscana in Italy and some places in Russia and Japan. Commercially, aplite is delivered from a.o. Maffei

Natural Resources, Italy and from US Silica Company, West Virginia, USA: Aplite typically contains silicon, magnesium, iron, sodium, aluminium, potassium, titanium and calcium, the main constituents being silicon and aluminium (in the form of oxides) typically being present in relative amounts in the range 60-85 % by weight and 10-25 % by weight respectively.

Suitable carbon fibres in the form of a separate mass or in a structured form, like woven or knitted mats, for use with the present invention can be supplied commercially from e.g. Devoid AMT, Langevaag, Norway.

In connection with the invention it is desirable with a quartz content in the aplite, calculated as SiO 2 stake, within the rage 68 to 95 % by weight.

By the method and the coating according to the present invention there is provided a three layer structure that each in different ways contributes to the overall properties in the formed coating. The first layer, when hardened, constitutes a very strong concrete with a compressive strength of up to 700 bar or more. With a convenient amount of aplite this layer will not draw water from the surface beneath (the matrix) if seepage of water to this layer should occur.

The second layer, the reinforcement layer, contributes to increased strength n the form of tensile strength and ductility and contributes to form a strong bonding between the first and the third layer. In addition the second layer contributes to increased stability of the coating and the coating structure with time.

The third layer primarily contributes to prevent any propagation of heat in the form of open flames, since it is able to resist heat without burning or disintegrating. The content of significant amounts of slag, preferably crude ore slag and calcite (CaCO 3 ) and anhydrite (CaSO 4 ) makes this layer a fire-proof barrier.

Preferred embodiments

Below a number of preferred, on-limiting embodiments of the invention is described.

For application of the first and third layer per se conventional spraying equipment intended for cement containing settable material compositions may be used. A typical and preferred layer thickness of the first layer is from 50 to 150 mm. This also applies for the third layer.

When applying the first layer, a water content in the range 40-50 % by weight of the dry substances is typically present in the settable material composition.

The micronized aplite mainly has a particle size less than 250 μm, preferably in the range 150-170 μm, but may also be less than 150 μm and in some cases less than 100 μm. In some embodiments it is preferred that at least 80 % o the aplite has a particle size less than 200 μm and in some embodiments it is preferred that at least 50 % of the aplite has a particle size less than 100 μm. When t is referred to particle size it should be understood if nothing else is stated, that ii is measured by conventional measurement techniques and standard sieve sizes. Alternatively the particle size could be determined with Coulter set of apparatus for determination of particle size.

The micronized aplite has a quartz content of at least 68 % by weight and more preferred at east 75 % by weight of the aplite.

The micronized aplite can be present as the sole cement component in the composition used in the first layer, i.e. as the only bonding agent in the first layer and that the reaction that causes the layer to set is controlled by adjusting pH in the settable composition to a level lower than 7, preferably lower than 5 and readily lower than 4. Such adjustment can - be made by adding a controlled amount of a mineral acid or organic acid. Any acidizing component that not adversely effects other components in the composition can be used. In other preferred embodiments, aplite can be used in the first layer along with at least one hydraulic cement, like a Portland cement, pozzolan cement, gypsum cement alumina cement silica cement and slag cement. Such conventional hydraulic cement is typically present in the first layer in an amount in the range 15-35 % by weight of the total cement material (aplite + conventional cement material). In the composition sprayed-on to form the first layer discrete carbon fibres and/ or microspheres can be present, the latter typically of a diameter in the range from about 5 μm to about 200 μm. Such micro-spheres contribute a.o. to improved flowing ability of the fresh settable material composition used to form the mentioned first layer and the mentioned third layer. By a convenient choice of micro-spheres, the micro-spheres can also positively influence the strength properties and/ or other properties of the final, hardened

composition constituting a layer of the coating according to the second aspect of the present invention. The micro-spheres can be made in materials chosen among glass, ceramics, polymers and carbon fibres.

The fibres of the reinforcement layer solely comprise fibres which are non-corrosive even in an acidic environment and are preferable carbon fibres. The fibres are preferably arranged in a structured form, such as, but not limited to, woven, knitted or braided form.

The fibres typically have a diameter in the range 1-15 μm, more preferred 3-10 μm, and most preferred 6-8 μm. When fibres such as carbon fibres are present as discrete fibres in the compositions forming first and/ or third layer, they preferably have a length in the range 1-100 mm and more preferred 3-25 mm.

The relative amount of anhydrite present in the composition forming the third layer typically is in the range 2-5 % by weight of the dry substance. The relative amount of calcite in the composition forming third layer also is in the range 2-5 % by weight of the dry substance.

The particle sizes of anhydrite and calcite are less important than the particle size of aplite and will generally have a rather broad distribution in which most of the material, typically 70-80 % thereof, within the range 0.1 - 5 mm.

Micronized aplite can be present as the sole bonding agent (cement component) in the composition used to form the third layer and the reaction causing the layer to set is controlled by adjusting pH of the settable material composition to a value lower than 7, preferably lower than 6, and more preferred lower than 5.

Also in the composition for the third layer micro-spheres having a typical diameter in the range from about 5 μm to about 200 μm can be included as well as discrete carbon fires as mentioned in relation to the composition of the first layer.

The matrix or the surface onto which the first layer is applied is typically an internal mountain wall that has been exposed by a technique chosen among drilling and blasting and optionally subsequent washing or cleaning, most typically wall surfaces and/ or ceiling surfaces in a tunnel, typically a tunnel for transportation, such as for roads or railway.

According to a further aspect the invention comprises a complete coating comprising at least three layers formed by any combination of the features described in connection with the method constituting the first aspect of the invention.

The coating, which is particularly suited as a fire, frost and water-proof coating in tunnels, thus comprises a first layer of a set material composition comprising micronized aplite, another layer in the for of a reinforcement layer and a third layer of a set material composition comprising aplite, anhydrite, slag and calcite.

The coating according to this aspect of the invention thus comprises the respective stakes of the individual components which above have been defined with reference to the method constituting the first aspect of the invention. Aplite from all known occurrences can be used though it is preferred that the aplite has a silicate (quartz) content of at least 68 % by weight and more preferred at least 75 %.

It is by the way possible to use quartz also from other sources than aplite in the first and third layers.

At least one of the layers chosen among first and third layer can include aplite granulate as an aggregate. Incidentally also materials chosen from materials like sand, gravel, anhydrite, glass, and foamed glass can be used as aggregate in the first and third layers.

The coating according to the present invention will during setting typically shrink less than 3 %, preferably less than 1.5 % and most preferred less than 0.7 %.

The method and the coating according to the present invention can be well suited for a number of applications of which the most obvious today is for coating of wall tunnels, particularly road tunnels with coatings that fulfil the strict demands for safety in the fields water, frost and not least fire.

The composition according to the invention satisfies such demands since especially the third layer with its content of slag, aplite, calcite (CaCO 3 ) and anhydrite (CaSO 4 ) form a strongly fire resistant barrier while the other layers contribute to provide strength to the structure.