[go: up one dir, main page]

EP1532329A1 - Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type - Google Patents

Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type

Info

Publication number
EP1532329A1
EP1532329A1 EP03760976A EP03760976A EP1532329A1 EP 1532329 A1 EP1532329 A1 EP 1532329A1 EP 03760976 A EP03760976 A EP 03760976A EP 03760976 A EP03760976 A EP 03760976A EP 1532329 A1 EP1532329 A1 EP 1532329A1
Authority
EP
European Patent Office
Prior art keywords
plaster
spray nozzle
layer
mixture
spray
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03760976A
Other languages
German (de)
French (fr)
Inventor
Jan Pieter Den Heten
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Combinatie Brandwerende Bekledingen Nederland VOF (CBBN)
Original Assignee
Combinatie Brandwerende Bekledingen Nederland VOF (CBBN)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Combinatie Brandwerende Bekledingen Nederland VOF (CBBN) filed Critical Combinatie Brandwerende Bekledingen Nederland VOF (CBBN)
Publication of EP1532329A1 publication Critical patent/EP1532329A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/04—Lining with building materials
    • E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
    • E21D11/105—Transport or application of concrete specially adapted for the lining of tunnels or galleries ; Backfilling the space between main building element and the surrounding rock, e.g. with concrete
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28C5/00—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions
    • B28C5/02—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions without using driven mechanical means effecting the mixing
    • B28C5/026—Mixing guns or nozzles; Injector mixers
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
    • C04B40/0028—Aspects relating to the mixing step of the mortar preparation
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
    • E04F21/00—Implements for finishing work on buildings
    • E04F21/02—Implements for finishing work on buildings for applying plasticised masses to surfaces, e.g. plastering walls
    • E04F21/06—Implements for applying plaster, insulating material, or the like
    • E04F21/08—Mechanical implements
    • E04F21/12—Mechanical implements acting by gas pressure, e.g. steam pressure
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00482—Coating or impregnation materials
    • C04B2111/00577—Coating or impregnation materials applied by spraying
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/20—Resistance against chemical, physical or biological attack
    • C04B2111/28—Fire resistance, i.e. materials resistant to accidental fires or high temperatures

Definitions

  • the present invention relates to a method for using a spray nozzle to spray on a layer of plaster, in which a plaster mixture to be sprayed out and a pressurized propellant gas, such as air, are fed to the spray nozzle and the gas and plaster mixture are brought together in the spray nozzle in order to be sprayed out of the nozzle.
  • a plaster mixture to be sprayed out and a pressurized propellant gas such as air
  • a method of this type is known, although it does not deal with a layer of plaster so much as a mixture of cement or grout.
  • the spraying of a cement/grout mixture is used in tunnel construction to finish walls and ceiling of a passage which has been drilled or hewn out of rock.
  • a phyllosilicate such as vermiculite, cement and water
  • any added plasticizers and/or setting accelerators to be sprayed on as a layer of plaster by means of a spray nozzle.
  • the above object is achieved through the fact that the plaster mixture comprises cement, water and a phyllosilicate, in particular vermiculite, and through the fact that the plaster mixture is fed to the spray nozzle with a density of approximately 690 to 860 kg/m 3 .
  • the plaster mixture After setting on the substrate, the plaster mixture reaches a high density, such as density of greater than 1000 kg/m 3 . Densities in the range from 1100 to 1310 kg/m 3 have proven achievable in practice, making the plaster mixture eminently suitable for use as a fireproof layer.
  • the Applicant has found that if the mixture of phyllosilicate, cement and water is supplied to the spray nozzle with the abovementioned density, this mixture can be sprayed successfully, with the aid of a pressurized gas, in particular air, via a spray nozzle without the spray nozzle becoming blocked or unsuitable in some other way for the automated spraying of a mixture of this type onto large surface areas.
  • the Applicant has found in particular that it is advantageous if the plaster mixture is fed to the spray nozzle with a density of 700 to 840 kg/m 3 , and it is particularly preferred if the plaster mixture is fed to the spray nozzle with a density of 750 to 820 kg/m 3 .
  • the plaster mixture is made up by mixing a dry mixture of phyllosilicate, in particular vermiculite, and cement with water in such a manner that the plaster mixture obtained has a density within the abovementioned ranges.
  • the dry mixture has a density, for example, of between 450 and 520 kg/m 3 .
  • the density of the plaster mixture has a density within the range at which the plaster mixture is ultimately fed to the spray nozzle as soon as it is made up, it is possible to considerably reduce the risk or extent of the density departing from the abovementioned ranges as it is being conveyed to the spray nozzle, which is of benefit to the structure of the plaster mixture.
  • the sprayed plaster mixture is under a pressure of 4 to 4.7 bar, in particular, a pressure of 4.2 to 4.5 bar, on the outlet side, in the spray opening, of the spray nozzle.
  • the plaster mixture is fed to the spray nozzle in such a manner that the pressure of the plaster mixture is at most 8 bar, preferably at most 7 bar.
  • 7 to 8 bar is a critical value for a plaster mixture, in particular a mixture comprising vermiculite, cement and water. How a supply of this nature is to be effected will be clear to a person skilled in the art as a function also of the distance which is to be spanned during supply.
  • the propellant gas in order to prevent undesired compression and resultant blockages, presumably caused by the formation of lumps, in the spray nozzle, according to the invention it is preferable for the propellant gas to be at a pressure of 4 to 7 bar at the entry side of the spray nozzle.
  • the opening of the spray nozzle during spraying is held at a distance of 1.0 to 2.5 m, in particular 1.5 to 2 m, from the substrate which is to be provided with the layer of plaster.
  • the layer of plaster can be sprayed onto a substantially dry substrate or at least that it is not necessary to wet the substrate in advance in order to improve adhesion.
  • the Applicant has found that the method according to the invention can be used particularly successfully for a substrate made from concrete of strength class B45 or above, such as strength classes B50, B60 or B65, or even a still higher strength class.
  • the spray opening, during spraying to be moved in translation, as seen transversely to the spraying direction, with a rotational movement superimposed on this translational movement. This results in a type of helical, elongate spraying pattern with overlapping adjoining spiral zones.
  • the substrate which is to be provided with a layer of plaster to be provided, prior to the layer of plaster being sprayed on, with pins which are positioned transversely with respect to the said substrate and which have a length equal to 1 to 3 mm less than a predetermined desired thickness of the layer of plaster, the plaster mixture then being sprayed on until the tips of the respective pins are no longer visible or at least no longer project out of the layer of plaster.
  • the pins can in this case be positioned at intervals of greater than 0.5 meter, in particular at intervals of from 1 to 2 meters.
  • the present invention relates to a method for applying a fireproof layer to the wall of a tunnel or viaduct which faces the road, the fireproof layer being a layer of plaster which is applied using the method according to the invention.
  • the present invention relates to a tunnel or viaduct provided with a layer of plaster sprayed on using the method according to the invention or provided with a fireproof layer applied using the method according to the invention for applying a fireproof layer.
  • Figure 1 shows a highly diagrammatic illustration of a spray nozzle with plaster mixture feed, propellant gas feed and a jet of sprayed plaster mixture
  • Figure 2 shows a highly diagrammatic, partially perspective view of a tunnel which is being provided with a layer of plaster using the method according to the invention
  • Figure 3 shows a highly diagrammatic illustration of a production line for making up a plaster mixture and spraying it in accordance with the invention.
  • Figure 4 shows a highly diagrammatic illustration of a spraying pattern from the spray nozzle which is preferred in accordance with the invention.
  • Fig. 1 shows a highly diagrammatic view of a spray nozzle 1 with an entry side 7 and an exit side 8.
  • a hose 2 which is used to supply the plaster mixture 3 is connected to the entry side 7.
  • the compressed air 5 is combined with the plaster mixture 3 which is to be sprayed in a manner which is known per se, for example by setting the plaster mixture in rotation via a tangential centripetal feed, in such a manner that a sprayed jet 6 of plaster mixture and air emerges at the exit side 8.
  • the plaster mixture advantageously consists of a mixture of vermiculite, cement, water and if appropriate plasticizers and/or setting accelerators.
  • This mixture is made up before being fed to the spray nozzle by a mixture of vermiculite and cement, as is commercially available under the name Fendolite M II, which is marketed by Cafco/Reppel.
  • Fendolite M II is entirely of mineral origin, is lightweight, fiber-free and has the particular property of remaining completely passive in the event of a fire. After the plaster layer has set, bound water is present between the individual sheets of the vermiculite grain insulation material, providing an additional insulating effect.
  • the compressed air 5 is supplied in accordance with the invention at a pressure of 4 to 7 bar at the entry side 7, approximately at the location indicated by 10. In particular, it is ensured that the plaster mixture in the spray nozzle, i.e.
  • the spray nozzle can be used for prolonged periods of time for spraying a layer of plaster on to large surface areas without the spray nozzle becoming blocked in the meantime.
  • the spray nozzle 1 is controlled by means of a spraying robot 12 and in accordance with the invention is advantageously held at a distance L of 1 m to 2.5 m from the substrate which is to be sprayed, in this case the tunnel wall.
  • the distance L will preferably lie in the range from 1.5 to 2 m.
  • the spraying robot comprises a laser which scans the surface which is to be sprayed between two diagonally opposite corners, in such a manner that the spraying robot is aware of the precise form of the surface which is to be sprayed and can control the spray nozzle accordingly, so that the surface which is to be sprayed is lined completely uniformly with a layer of plaster, in particular with a minimum guaranteed layer thickness.
  • the spraying robot will in this process during spraying constantly adapt the position of the spray nozzle to the measured unevenness.
  • the spray nozzle 1 is controlled so as to execute a translational, whether straight or curved, movement 13 with the rotational movement superimposed on it, in such a manner that the spraying pattern follows a type of helical pattern, as highly diagrammatically indicated in fig. 4.
  • the tunnel wall prefferably lined with a mesh structure before the layer of plaster is sprayed onto it, which mesh structure will be embedded in the layer of plaster after the layer of plaster has been sprayed on.
  • a mesh structure of this type is very diagrammatically indicated by 14 in fig. 2.
  • the substrate which is to be lined is provided with a number of pins 15 which project from the substrate over a height which is approximately equal to approximately 1 to 3 mm less than the predetermined desired minimum thickness of the layer of plaster.
  • Pins 15 of this type will in particular be provided at certain intervals in accordance with a preferably regular pattern.
  • a pattern of this type may be a square grid pattern with intervals of approximately 1 to 2 meters between the adjacent pins 15.
  • This overall installation comprises a diagrammatically indicated train of carriages.
  • the rear side of this train is formed by an exchangeable carriage or exchangeable carriages with stocks of raw material.
  • stocks of raw material will in particular comprise a dry mixture of vermiculite and cement.
  • the stocks of raw material may also comprise water for making up the plaster mixture.
  • the stocks of raw material may also comprise compressed-air cylinders or spraying by means of a spraying robot. These stocks of raw materials may be provided on different carriages.
  • These stocks of raw materials are diagrammatically indicated by 15.
  • a buffer silo in particular for the dry mixture of vermiculite and cement, provided in front of the carriage carrying the stocks of raw material.
  • a double mixing installation 17 is provided in front of the buffer silo carriage 16.
  • This double mixing installation 17 comprises two batch mixers which can be provided on one carriage or if appropriate on two carriages. These batch mixtures can alternate in terms of mixing mode, in which case one is always in mixing mode for making up a portion of plaster mixture and the other is full of plaster mixture which has been made up for supply to the spray nozzle 1. This supply of the plaster mixture to the spray nozzle 1 takes place via a hose 2 and one or more pumps 20.
  • the pumps 20 are in particular set in such a manner that the pressure of the plaster mixture at the exit side is at most 7 to 8 bar, preferably at most 7 bar.
  • the pump used may in particular be what is known as a progressive (or progressing) cavity pump. This is a pump of the so-called single screw type.
  • a progressive cavity pump of this type a rotor rotates inside a stator, the stator being a twisted cavity with an oval cross section.
  • the stator is in this case generally made from a natural or synthetic rubber, from steel or from plastic and the rotor is generally made from steel.
  • the spray nozzle 1 can end in the form of a spray lance 25 where the plaster mixture together with the propellant gas leaves the spray nozzle.
  • An energy carriage 19 from which electrical energy can be supplied to the various components of the train with carriages is generally also incorporated in the train of carriages.
  • a spraying robot carriage, on which the spray nozzle is provided and from which the spraying of plaster mixture will take place, is incorporated at the front of the train.

Landscapes

  • Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Architecture (AREA)
  • Chemical & Material Sciences (AREA)
  • Civil Engineering (AREA)
  • Ceramic Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Materials Engineering (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
  • Lining And Supports For Tunnels (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Nozzles (AREA)

Abstract

The invention relates to a method for using a spray nozzle to spray on a layer of plaster, in which a plaster mixture and a pressurized gas, such as air, are fed to the spray nozzle under pressure and the gas and plaster mixture are brought together in the spray nozzle in order to be sprayed out of the nozzle. The plaster mixture comprises a phyllosilicate, in particular vermiculite, cement and water. The plaster mixture has a density of approximately 690 to 860 kg/m3 before it reaches the spray nozzle. The plaster mixture is under a pressure of 4 to 4.7 bars on the entry of the spray nozzle. The gas is at a pressure of 4 to 7 bars on the entry side of the spray nozzle. During the spraying operation, the spray nozzle is held at a distance of 1.0 m to 2.5 m from the substrate which is to be provided with a layer of plaster. The invention is also relates to a tunnel viaduct provided with a layer of plaster sprayed on using the method according to the invention or with a fireproof layer applied using the method as described in claim 13.

Description

Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type
The present invention relates to a method for using a spray nozzle to spray on a layer of plaster, in which a plaster mixture to be sprayed out and a pressurized propellant gas, such as air, are fed to the spray nozzle and the gas and plaster mixture are brought together in the spray nozzle in order to be sprayed out of the nozzle.
A method of this type is known, although it does not deal with a layer of plaster so much as a mixture of cement or grout. The spraying of a cement/grout mixture is used in tunnel construction to finish walls and ceiling of a passage which has been drilled or hewn out of rock.
It is known from the oil industry to apply a mixture of vermiculite, cement and water as a layer of plaster to steel structural parts in order to provide them with a fireproof layer. However, a mixture of vermiculite, cement and water of this type cannot be sprayed onto a substrate in an automated manner by means of a spray nozzle, on account of the fact that, for example, the spray nozzle becomes blocked, the spray material is not uniformly applied to the substrate, the spray material applied to the substrate has an undesired spread in density. This means that it is not readily possible to use a mixture of vermiculite, cement and water of this type as a fireproof layer on very large surfaces.
It is an object of the present invention to provide a method which allows a plaster mixture comprising a phyllosilicate, such as vermiculite, cement and water and any added plasticizers and/or setting accelerators, to be sprayed on as a layer of plaster by means of a spray nozzle.
According to the invention, in the method of the type described in the introduction the above object is achieved through the fact that the plaster mixture comprises cement, water and a phyllosilicate, in particular vermiculite, and through the fact that the plaster mixture is fed to the spray nozzle with a density of approximately 690 to 860 kg/m3. After setting on the substrate, the plaster mixture reaches a high density, such as density of greater than 1000 kg/m3. Densities in the range from 1100 to 1310 kg/m3 have proven achievable in practice, making the plaster mixture eminently suitable for use as a fireproof layer. The Applicant has found that if the mixture of phyllosilicate, cement and water is supplied to the spray nozzle with the abovementioned density, this mixture can be sprayed successfully, with the aid of a pressurized gas, in particular air, via a spray nozzle without the spray nozzle becoming blocked or unsuitable in some other way for the automated spraying of a mixture of this type onto large surface areas. In this context, the Applicant has found in particular that it is advantageous if the plaster mixture is fed to the spray nozzle with a density of 700 to 840 kg/m3, and it is particularly preferred if the plaster mixture is fed to the spray nozzle with a density of 750 to 820 kg/m3.
Since in particular blockage of the nozzle is reliably avoided, in accordance with the invention it is in this case preferred if, prior to the spraying operation, the plaster mixture is made up by mixing a dry mixture of phyllosilicate, in particular vermiculite, and cement with water in such a manner that the plaster mixture obtained has a density within the abovementioned ranges. The dry mixture has a density, for example, of between 450 and 520 kg/m3. After it has been made up, the plaster mixture will generally be fed to the spray nozzle by means of a pump. By ensuring that the density of the plaster mixture has a density within the range at which the plaster mixture is ultimately fed to the spray nozzle as soon as it is made up, it is possible to considerably reduce the risk or extent of the density departing from the abovementioned ranges as it is being conveyed to the spray nozzle, which is of benefit to the structure of the plaster mixture.
To substantially prevent the spray nozzle from becoming blocked, according to the invention it is preferred if the sprayed plaster mixture is under a pressure of 4 to 4.7 bar, in particular, a pressure of 4.2 to 4.5 bar, on the outlet side, in the spray opening, of the spray nozzle. Where the present text and the text which follows refers to pressures, it will be clear to the person skilled in the art that these are excess pressures with respect to atmospheric pressure.
To prevent undesired compaction of the plaster mixture as it is being conveyed to the spray nozzle, according to the invention it is preferable if the plaster mixture is fed to the spray nozzle in such a manner that the pressure of the plaster mixture is at most 8 bar, preferably at most 7 bar. The Applicant has found that 7 to 8 bar is a critical value for a plaster mixture, in particular a mixture comprising vermiculite, cement and water. How a supply of this nature is to be effected will be clear to a person skilled in the art as a function also of the distance which is to be spanned during supply. This involves selecting a suitable type of pump and if the distances are relatively great if appropriate using a plurality of pumps which are each selected or set in such a way that the pressure at the exit side of the pump in question does not exceed the abovementioned 7 to 8 bar.
In order to prevent undesired compression and resultant blockages, presumably caused by the formation of lumps, in the spray nozzle, according to the invention it is preferable for the propellant gas to be at a pressure of 4 to 7 bar at the entry side of the spray nozzle.
To enable the plaster mixture to be sprayed reliably onto a substrate taking account in particular of the density of the plaster mixture and to a lesser extent also taking account of the pressures prevailing in the spray nozzle, according to the invention it is preferable for the opening of the spray nozzle during spraying to be held at a distance of 1.0 to 2.5 m, in particular 1.5 to 2 m, from the substrate which is to be provided with the layer of plaster. The result of this is that the plaster mixture, when it reaches the substrate, will strike this substrate with sufficient force to ensure that the layer of plaster sticks sufficiently securely, so that it can set without falling off the substrate.
The Applicant has found that to achieve sufficient bonding, the layer of plaster can be sprayed onto a substantially dry substrate or at least that it is not necessary to wet the substrate in advance in order to improve adhesion.
The Applicant has found that the method according to the invention can be used particularly successfully for a substrate made from concrete of strength class B45 or above, such as strength classes B50, B60 or B65, or even a still higher strength class.
To enable the method according to the invention to be used to apply a layer of plaster with a good coverage, according to the invention it is preferable for the spray opening, during spraying, to be moved in translation, as seen transversely to the spraying direction, with a rotational movement superimposed on this translational movement. This results in a type of helical, elongate spraying pattern with overlapping adjoining spiral zones.
To provide a visual check of the thickness of the layer of plaster applied during spraying of the layer of plaster and in this way to make it possible to ensure a specific minimum plaster layer thickness, according to the invention it is preferable for the substrate which is to be provided with a layer of plaster to be provided, prior to the layer of plaster being sprayed on, with pins which are positioned transversely with respect to the said substrate and which have a length equal to 1 to 3 mm less than a predetermined desired thickness of the layer of plaster, the plaster mixture then being sprayed on until the tips of the respective pins are no longer visible or at least no longer project out of the layer of plaster. The pins can in this case be positioned at intervals of greater than 0.5 meter, in particular at intervals of from 1 to 2 meters.
According to a further aspect, the present invention relates to a method for applying a fireproof layer to the wall of a tunnel or viaduct which faces the road, the fireproof layer being a layer of plaster which is applied using the method according to the invention.
According to yet another aspect, the present invention relates to a tunnel or viaduct provided with a layer of plaster sprayed on using the method according to the invention or provided with a fireproof layer applied using the method according to the invention for applying a fireproof layer.
The present invention will be explained in more detail below with reference to a highly diagrammatic drawing in which:
Figure 1 shows a highly diagrammatic illustration of a spray nozzle with plaster mixture feed, propellant gas feed and a jet of sprayed plaster mixture; Figure 2 shows a highly diagrammatic, partially perspective view of a tunnel which is being provided with a layer of plaster using the method according to the invention;
Figure 3 shows a highly diagrammatic illustration of a production line for making up a plaster mixture and spraying it in accordance with the invention; and
Figure 4 shows a highly diagrammatic illustration of a spraying pattern from the spray nozzle which is preferred in accordance with the invention.
Fig. 1 shows a highly diagrammatic view of a spray nozzle 1 with an entry side 7 and an exit side 8. A hose 2 which is used to supply the plaster mixture 3 is connected to the entry side 7. A propellant gas feed line 4, via which in this case compressed air 5 is supplied, is also connected to the entry side 7. hi the spray nozzle 1, the compressed air 5 is combined with the plaster mixture 3 which is to be sprayed in a manner which is known per se, for example by setting the plaster mixture in rotation via a tangential centripetal feed, in such a manner that a sprayed jet 6 of plaster mixture and air emerges at the exit side 8. According to the invention, the plaster mixture advantageously consists of a mixture of vermiculite, cement, water and if appropriate plasticizers and/or setting accelerators. This mixture is made up before being fed to the spray nozzle by a mixture of vermiculite and cement, as is commercially available under the name Fendolite M II, which is marketed by Cafco/Reppel. Fendolite M II is entirely of mineral origin, is lightweight, fiber-free and has the particular property of remaining completely passive in the event of a fire. After the plaster layer has set, bound water is present between the individual sheets of the vermiculite grain insulation material, providing an additional insulating effect.
To enable the mixture of vermiculite, cement and water to be sprayed, according to the invention it has proven very important for this plaster mixture to be fed to the spray nozzle with a density in the range from 700 to 840 kg/m3, in particular a density in the range from 750 to 820 kg/m3, at the entry side 7, approximately at the location indicated by 9. To ensure that the propellant gas on the one hand has a sufficient spraying action and on the other hand does not excessively influence the density of the plaster mixture, the compressed air 5 is supplied in accordance with the invention at a pressure of 4 to 7 bar at the entry side 7, approximately at the location indicated by 10. In particular, it is ensured that the plaster mixture in the spray nozzle, i.e. approximately at the location of 11, after it has been combined with the propellant gas 5, is at a pressure in the range from 4 to 4.7 bar, in particular in the range from 4.2 to 4.5 bar. If the mixture of the vermiculite, cement and water and propellant gas is sprayed out of the spray nozzle at this level of pressure, the Applicant has found that the spray nozzle can be used for prolonged periods of time for spraying a layer of plaster on to large surface areas without the spray nozzle becoming blocked in the meantime.
Referring now to fig. 2, with the method according to the invention it is highly advantageously possible to line the inner wall of a tunnel with a fireproof layer of vermiculite, cement and water. In the process, the spray nozzle 1 is controlled by means of a spraying robot 12 and in accordance with the invention is advantageously held at a distance L of 1 m to 2.5 m from the substrate which is to be sprayed, in this case the tunnel wall. The distance L will preferably lie in the range from 1.5 to 2 m.
The spraying robot comprises a laser which scans the surface which is to be sprayed between two diagonally opposite corners, in such a manner that the spraying robot is aware of the precise form of the surface which is to be sprayed and can control the spray nozzle accordingly, so that the surface which is to be sprayed is lined completely uniformly with a layer of plaster, in particular with a minimum guaranteed layer thickness. The spraying robot will in this process during spraying constantly adapt the position of the spray nozzle to the measured unevenness. To ensure that a uniform layer of plaster with good coverage is obtained during spraying, according to the invention it is preferable for the spraying robot 12 to control the spray nozzle 1 during spraying in such a manner that it follows a spraying pattern corresponding to that shown in fig. 4, i.e. the spray nozzle 1 is controlled so as to execute a translational, whether straight or curved, movement 13 with the rotational movement superimposed on it, in such a manner that the spraying pattern follows a type of helical pattern, as highly diagrammatically indicated in fig. 4.
To ensure that the layer of plaster remains attached to the tunnel wall with a very high level of reliability even in the event of exposure to fire, according to the invention it is preferable for the tunnel wall to be lined with a mesh structure before the layer of plaster is sprayed onto it, which mesh structure will be embedded in the layer of plaster after the layer of plaster has been sprayed on. A mesh structure of this type is very diagrammatically indicated by 14 in fig. 2.
To allow visual inspection in order to be especially certain after the operation has finished that the layer of plaster has a certain predetermined minimum thickness over the entire surface (which is very important in connection with fireproofing) and if appropriate to enable any problems of this nature to be corrected while the layer of plaster is being sprayed on, according to the invention it is highly preferable if, before the layer of plaster is sprayed on, the substrate which is to be lined is provided with a number of pins 15 which project from the substrate over a height which is approximately equal to approximately 1 to 3 mm less than the predetermined desired minimum thickness of the layer of plaster. Pins 15 of this type will in particular be provided at certain intervals in accordance with a preferably regular pattern. A pattern of this type may be a square grid pattern with intervals of approximately 1 to 2 meters between the adjacent pins 15.
Reference will now be made to fig. 3, which provides a highly diagrammatic illustration of an overall installation which can be used to carry out the method according to the invention. This overall installation comprises a diagrammatically indicated train of carriages. The rear side of this train is formed by an exchangeable carriage or exchangeable carriages with stocks of raw material. These stocks of raw material will in particular comprise a dry mixture of vermiculite and cement. The stocks of raw material may also comprise water for making up the plaster mixture. The stocks of raw material may also comprise compressed-air cylinders or spraying by means of a spraying robot. These stocks of raw materials may be provided on different carriages. These stocks of raw materials are diagrammatically indicated by 15. There is a buffer silo, in particular for the dry mixture of vermiculite and cement, provided in front of the carriage carrying the stocks of raw material. A double mixing installation 17 is provided in front of the buffer silo carriage 16. This double mixing installation 17 comprises two batch mixers which can be provided on one carriage or if appropriate on two carriages. These batch mixtures can alternate in terms of mixing mode, in which case one is always in mixing mode for making up a portion of plaster mixture and the other is full of plaster mixture which has been made up for supply to the spray nozzle 1. This supply of the plaster mixture to the spray nozzle 1 takes place via a hose 2 and one or more pumps 20. In accordance with the invention, the pumps 20 are in particular set in such a manner that the pressure of the plaster mixture at the exit side is at most 7 to 8 bar, preferably at most 7 bar. The pump used may in particular be what is known as a progressive (or progressing) cavity pump. This is a pump of the so-called single screw type. In a progressive cavity pump of this type, a rotor rotates inside a stator, the stator being a twisted cavity with an oval cross section. The stator is in this case generally made from a natural or synthetic rubber, from steel or from plastic and the rotor is generally made from steel.
The spray nozzle 1 can end in the form of a spray lance 25 where the plaster mixture together with the propellant gas leaves the spray nozzle.
An energy carriage 19 from which electrical energy can be supplied to the various components of the train with carriages is generally also incorporated in the train of carriages. Finally, a spraying robot carriage, on which the spray nozzle is provided and from which the spraying of plaster mixture will take place, is incorporated at the front of the train.

Claims

Claims
1. A method for using a spray nozzle to spray on a layer of plaster, in which a plaster mixture to be sprayed out and a pressurized propellant gas, such as air, are fed to the spray nozzle and the gas and plaster mixture are brought together in the spray nozzle in order to be sprayed out of the nozzle, characterized in that the plaster mixture comprises a phyllosilicate, in particular vermiculite, cement and water, and in that the plaster mixture is fed to the spray nozzle with a density of approximately 690 to 860 kg/m3.
2. The method as claimed in claim 1, in which the plaster mixture is fed to the spray nozzle with a density of 700 to 840 kg/m3.
3. The method as claimed in claim 2, in which the plaster mixture is fed to the spray nozzle with a density of 750 to 820 kg/m3.
4. The method as claimed in one of the preceding claims, in which prior to the spraying the plaster mixture is made up by mixing a dry mixture of phyllosilicate and cement with water in such a manner that the plaster mixture obtained has a density as described in one of claims 1-3.
5. The method as claimed in one of the preceding claims, in which the plaster mixture in the spray opening of the spray nozzle is at a pressure of 4 to 4.7 bar, in particular a pressure of 4.2 to 4.5 bar.
6. The method as claimed in one of the preceding claims, in which the plaster mixture is fed to the spray nozzle in such a manner that the pressure of the plaster mixture is at most 8 bar, preferably at most 7 bar.
7. The method as claimed in one of the preceding claims, in which the propellant gas on the entry side of the spray nozzle is at a pressure of 4 to 7 bar.
8. The method as claimed in one of the preceding claims, in which during the spraying the opening of the spray nozzle is held at a distance of 1.0 m to 2.5 m, in particular 1.5 m to 2 m, from the substrate which is to be provided with the layer of plaster.
9. The method as claimed in one of the preceding claims, in which the substrate which is to be provided with the layer of plaster is substantially dry or at least is not wetted in advance.
10. The method as claimed in one of the preceding claims, in which the substrate comprises concrete of strength class B45 or above, such as B50, B60 or B65, or if appropriate higher.
11. The method as claimed in one of the preceding claims, in which during the spraying, the spray nozzle is moved in translation, as seen transversely to the direction of spraying, with a rotational movement superimposed on this translational movement.
12. The method as claimed in one of the preceding claims, in which the substrate which is to be provided with a layer of plaster is provided, prior to the plaster layer being sprayed on, with pins which are positioned transversely with respect to the said substrate, which pins have a length equal to 1 to 2 mm less than a predetermined desired thickness for the layer of plaster, and in which the plaster mixture is sprayed on until the tips of the corresponding pins are no longer visible or at least no longer project out of the layer of plaster.
13. A method as claimed in claim 12, in which the pins are positioned at intervals of greater than 0.5 meter, in particular at intervals of 1 to 2 meters.
14. A method for applying a fireproof layer to the wall of a tunnel or viaduct facing the road, the fireproof layer being a layer of plaster which is applied using the method as claimed in one of claims 1-13.
15. A tunnel or viaduct provided with a layer of plaster sprayed on using the method as claimed in one of claims 1-13 or provided with a fireproof layer applied using the method as claimed in claim 14.
EP03760976A 2002-06-21 2003-06-23 Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type Withdrawn EP1532329A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
NL1020920 2002-06-21
NL1020920A NL1020920C2 (en) 2002-06-21 2002-06-21 Method for spraying a plaster layer with a spray nozzle and tunnel or viaduct provided with such a plaster layer.
PCT/NL2003/000460 WO2004001158A1 (en) 2002-06-21 2003-06-23 Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type

Publications (1)

Publication Number Publication Date
EP1532329A1 true EP1532329A1 (en) 2005-05-25

Family

ID=29997572

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03760976A Withdrawn EP1532329A1 (en) 2002-06-21 2003-06-23 Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type

Country Status (5)

Country Link
EP (1) EP1532329A1 (en)
AU (1) AU2003248156A1 (en)
NL (1) NL1020920C2 (en)
NO (1) NO20045606L (en)
WO (1) WO2004001158A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101906978B (en) * 2010-07-23 2012-04-04 中国矿业大学 Concrete sprayer with horizontal rotor of side blowing type
WO2014188221A2 (en) * 2013-05-23 2014-11-27 Q-Bot Limited Method of covering a surface of a building and robot therefor
FR3048427B1 (en) * 2016-03-04 2021-04-23 Orapi COMPOSITION OF PLASTER AND USE AS A PLASTER

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3714386A1 (en) * 1987-04-30 1988-12-01 Degussa METHOD AND SPRAY APPLIANCE FOR APPLYING A SPRAY CONCRETE LAYER
US6004626A (en) * 1998-07-10 1999-12-21 North American Refractories Co. High pressure/volume process for wet shotcreting a refractory castable
US6309740B1 (en) * 1999-07-20 2001-10-30 W. R. Grace & Co.-Conn. High temperature heat transfer barrier and vapor barrier and methods

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004001158A1 *

Also Published As

Publication number Publication date
NO20045606L (en) 2005-03-21
WO2004001158A1 (en) 2003-12-31
AU2003248156A1 (en) 2004-01-06
NL1020920C2 (en) 2003-12-23

Similar Documents

Publication Publication Date Title
US5389167A (en) Method for insulating a cavity
CA2109848C (en) Method for applying a foamed fiber insulation
US9499980B2 (en) Lightweight cementitious panel possessing high durability background
US20080050578A1 (en) Beam insulating material
CN101395325A (en) reinforced cement shear board
AU2002212800B2 (en) Composite panel for repairing, reinforcing con'c body and method of using the same
AU2002212800A1 (en) Composite panel for repairing, reinforcing con'c body and method of using the same
US20150076728A1 (en) Controlling the embedding depth of reinforcing mesh to cementitious board
CA1338560C (en) Apparatus for pneumatically discharging a hardening building material, in particular, a hydraulic air-placed concrete or mortar
US20150076726A1 (en) Process for expanding small diameter polystyrene beads for use in cementitious board
WO2004001158A1 (en) Method for using a spray nozzle to spray on a layer of plaster, and tunnel or viaduct provided with a layer of plaster of this type
WO1980001888A1 (en) Moulding of construction products
US20100304122A1 (en) Cementitious siding having encapsulated foam core, and system and method for making the same
US20060243747A1 (en) Hose pump feeding device
US6450735B1 (en) Method and equipment for ventilating underground workings
US20100263315A1 (en) Molded siding having integrally-formed i-beam construction
CN106836683A (en) A kind of construction method of Machine-made Sand aggregate dry-mixed mortar coated building metope
AU659082B2 (en) Ferrocement composition, method of forming objects therefrom and apparatus for use in such a method
JPS594194B2 (en) Cement mortar spraying method
KR20000077504A (en) Insulating plate for constructing
JP2885956B2 (en) Construction method of mortar outer wall for low-rise houses
DE102020214655B9 (en) Thermal insulation plaster system and method for its production
CN216893619U (en) UHPC reinforcing equipment of underground cavern
RU2187652C2 (en) Method of mine working air isolation
JPS6164956A (en) In-site spray finishing construction method by fiber reinforced cement

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20041220

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL LT LV MK

DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20070102