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.

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

Applications Claiming Priority (3)

Publications (1)

Family

ID=29997572

Family Applications (1)

Country Status (5)

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• 2002
  • 2002-06-21 NL NL1020920A patent/NL1020920C2/nl not_active IP Right Cessation
• 2003
  • 2003-06-23 EP EP03760976A patent/EP1532329A1/de not_active Withdrawn
  • 2003-06-23 WO PCT/NL2003/000460 patent/WO2004001158A1/en not_active Application Discontinuation
  • 2003-06-23 AU AU2003248156A patent/AU2003248156A1/en not_active Abandoned
• 2004
  • 2004-12-22 NO NO20045606A patent/NO20045606L/no not_active Application Discontinuation

Non-Patent Citations (1)

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