EP1978207A2 - Fire protection for structures - Google Patents

Abstract

The fire protection has a sealing against water, particularly in form of a foil, and has anchors, which are brought into the rock mass to hold tunnel lining. The fasteners are used, which are brought into a side gunite layer, and also hold tunnel lining. A lightweight concrete is provided as gunite and fire protection, which consist a part from plastic foam particles, and holds a fire load of 1000 degrees celsius for 90 minutes. The expanded polystyrene particles are provided,which has an adhesion mediator at the surface.

Description

The invention relates to the fire protection of buildings, especially in underground spaces such as tunnels and tunnels.

In road traffic tunnels have already occurred dramatic fires with many victims. The same applies to above-ground structures. In any case, it is of particular importance that affected persons can escape from the fire. In the tunnel, the escape can easily encounter great difficulties. The same applies in above-ground structures. Therefore, one is usually endeavored to set up escape routes. Another solution is to use fire-retardant materials that withstand fire for a while so that the people concerned can get to safety.

Fire protection means all measures that prevent the spread of fire and smoke. The structural measures in buildings are very diverse and include in particular the building materials and components, regulated in DIN 4102 and ENV 1992-1-2.

First, the invention will be discussed in the application to tunnels. In tunnel structures, fire protection has gained considerable importance in recent years due to various fire cases. In addition to compliance with constructive rules, more and more computational evidence is required, cf. for example ENNV 1992-1-2. For the assessment of fire protection, the fire resistance / fire resistance of a component is of crucial importance. It is measured by the duration that a component retains its function in case of fire.
The building materials are divided into non-combustible building materials and combustible building materials. Usual fire resistance skis are: F0 (in case of fire functional for less than 30 minutes, F30 fire-retardant (at least 30 minutes in case of fire), highly fire resistant (at least 60 minutes in case of fire, F90 fire-resistant (at least 90 minutes in case of fire), F120 highly resistant to fire (in case of fire at least 120 minutes functional), F180 fire-resistant (in case of fire for at least 180 minutes) The fire situation in all countries subject to the approval requirement for the use of combustible building materials involves a fire load with a temperature between 1000 and 1200 degrees Celsius.

It must be distinguished between the tunnels in stable mountains and unstable mountains. A stable mountain does not collapse after the tunnel eruption. In contrast, in a non-stable mountains, a sustainable development of the tunnel is required, which partially absorbs the weight of the mountain. In non-stable mountains, both a steel construction and a concrete construction is common. It can also find combinations of steel and concrete application. The concrete construction will mostly be made at the construction site. There are also concrete panels usual, which are manufactured in the factory and transported to the site.

In sturdy mountains, the strength problem is partially eliminated.
There remains the problem of how to protect against falling stones. The problem is usually solved with shotcrete. In the process, concrete is sprayed against the mountain eruption, which hardens there and forms a protective skin.

Another problem is leaking mountain water.
In winter, the water freezes. There is a danger of falling ice masses. This danger is usually met with a film seal. Depending on the thickness of the film is also spoken by webs. In part, there is also the name membrane.

The foil seal dissipates the water. At the same time a freezing of the water is prevented with a thermal insulation. The thermal insulation can be made of polyethylene foam. The thermal insulation can be arranged inside the tunnel in front of the film seal. Depending on the nature of the thermal insulation may be connected to the film seal or at the same time form the seal. The thermal insulation as well as the film seal can be welded or glued to the joints. Preferably, an overlap of the film edges or the edges of the thermal insulation takes place. Optionally, a compound of the film edges or the edges of the insulation with a strip of material by welding or gluing is provided.
As far as is spoken in the further of a film seal and / or thermal insulation, includes the above possibilities.

Usually, the film seal is composed of film webs. The film webs are usually laid overlapping on the mountain outbreak, so that the film edges can then be welded together.
Preferably, a double seam is produced during welding. There are two welds next to each other. The gap can be pressurized with air pressure. When the gap is closed, a sufficient sealing effect can be assumed if the pressure drop in the intermediate space does not exceed certain limits over a certain period of time.

The attachment of the film is done in different ways.
With low strength requirements has in the past enforced a film attachment with a trained as a rondelle fastener made of plastic. The rondelle is nailed or shot to the mountains or to a first shotcrete layer applied. When shooting the roundels are not hit with a hammer or the like in the mountains, but driven by a blasting cartridge in the mountains or in the first applied shotcrete layer.

The known roundels are for example in the DE-3244000C1 . DE4100902A1 . DE19519595A1 . DE8632994.4U1 . DE8701969.8U1 . DE20217044U1 shown and described. The known roundels have been welded to the film. Rondelles with a predetermined breaking point were considered to be particularly favorable. The rondels should break at a load on the film at the predetermined breaking point. The strength of the predetermined breaking point is significantly lower than the film strength. This will cause the rondelle to break first if excessive tension is applied to the foil. That is, the film seal will remain intact upon excessive pull in the film while the disk ruptures.

However, the plastic rondels are only suitable if low forces arise during the attachment of the films and subsequent application of shotcrete.

However, especially in tunnels high forces occur. In railway tunnels, the passing trains generate an extreme air pressure and then an extreme induced draft. The pressures act on extremely large areas, so that total pressures arise, which requires a sufficiently strong connection of Tuhnelausbaus with the mountains. The pressures depend on the speed of the trains. High-speed trains once again increase the pressures many times over normal railways.
The same applies to motor vehicle tunnels.

At such load, steel rondelles have prevailed as fasteners, which are held with anchors in the mountains.
The anchors also have the task of keeping the tunnel excavation at a distance from the rock outcrop and directing the traffic loads acting on the tunnel construction into the mountains.

The known roundels have a diameter of about 150 mm and a thickness of 3 to 4 millimeters. Such rondels have great strength.

The known anchors have diameters of 12 or 14 or 16 or 20mm. They are preferably made of stainless steel and are profiled on the mountain side to develop a high tensile strength in the mountains. For the anchor corresponding holes are introduced into the mountains. Subsequently, the anchors are fixed with a mounting cement or other suitable mounting means in the holes.
Such anchors can absorb much larger forces in contrast to the known nail construction. The loads are directed to the mountains. With the anchors, it is therefore possible to build a tunnel that can withstand the stresses of passing trains and passing vehicles.
At the free end of the anchor are usually provided with a thread, preferably according to the diameter with metric thread M12 or M14 or M16 or M20. At the threaded end, the steel rondelles are held between two screws. The screws allow adjustment of the rondels on the anchor.

The anchors are usually so long that they protrude beyond the steel rondels out into the tunnel. This serves to attach a wire grid as a retention during injection of the concrete and to stiffen the tunnel lining by connecting to the mountains.

When spraying concrete against a film there is a risk that the film throws off the concrete or the concrete does not adhere to the film. Then it is expedient to provide at a distance in front of the film, a wire mesh or the like, which prevents falling of the concrete.

The wire mesh also serves to reinforce the shotcrete layer.

On the anchor, a spacer for the wire mesh can be mounted. Known spacers are star-shaped provided with rods to support the wire mesh as large as possible.

In the known construction pierce the anchor the film.

The film is then clamped between the steel rondels.
Of the two rondels is a rondelle on the outside of the film seal and the other Rondelle inside the film seal.

In practice, it can be seen that the mountain water runs along the anchors. As a result, the anchors and the rondelles are subject to corresponding water pollution.
The invention has recognized that the water penetrates through the screw thread of Rondellen and anchor. The water then also passes through the opening formed in the film. There are leaks. Even a dropwise leakage leads to significant amounts of water in a corresponding time. The water can escape at the inside of the tunnel. In winter, the invading water freezes. It forms icicles, which fall at the latest in thawing thawing and form a bad risk of accidents. In addition, the ice can cause significant destruction of the tunnel.

In order to prevent the ingress of water on the thread of the Rondelle, it is known to insert a rubber ring in the passage opening of the Rondelle. However, the rubber ring has only a very limited effect, because he can not reach sufficiently into the threads of the anchor. Although it is known to provide the rubber ring on the thread side with knobs that should better grip between the threads than a smooth ring. There are also other solutions for sealing the penetration.

The construction described above with a distance from the mountain excavation tunnel construction is a variant. There is also tunnel construction, which rests directly on the mountain eruption. This variant is particularly advantageous in unstable mountains, because it supports the mountains directly, so that the mountain outbreak only withstand static forces, while a distanced tunnel construction is additionally burdened by the dynamic forces of erupting rock.

Optionally, the tunnel construction supporting the mountain provides that a shotcrete layer is first applied to the rock outcrop. This layer has the task to seal the surface of the mountain eruption, in order to prevent a so-called leafing of the mountain layers. In particular, in the shotcrete layer holder for a plastic seal are attached. On the inside, a load-bearing concrete layer is built up on the plastic seal. This concrete layer is either cast or shotcrete. The shotcrete is handled in the same way as in the above-described spaced tunnel construction.
This includes mesh and other measures to facilitate the shotcrete build-up at the seal.

According to an older proposal, a lightweight concrete is applied to the seal as shotcrete layer. The lightweight concrete has after the older proposal supplements of plastic foam particles, preferably wholly or partly made of polystyrene, which carries the short name EPS.
There are also other plastics come for foam particles into consideration.

Such lightweight concrete is described for example in WO2004 / 101460A1 . WO 00/06515 . US 5618344A . US 4547223A . EP 725043A . WO 9.4 / (05896 . EP 295628B1 . FR 2499453 . EP 449360A1 . DE19831295A1 . DE 2127421 . EP 1590308A1 . EP 1122223A1 . DD297386A5 . DE 19529695A1 . DE 4406866A1 ,

The lightweight concrete has processing advantages in tunnel construction. As the name says, the lightweight concrete is comparatively light compared to normal concrete. The lightweight concrete is easier to build up as a layer than normal concrete, Due to the lower weight of light concrete slides / flows not so easy down.
Lightweight concrete also has heat-insulating properties.

Optionally, a plastic foam, in particular a polyethylene (PE) foam is used in addition to the thermal insulation, as described above. The PE foam finds a hold on the same anchors as the membrane.

Also, when the lightweight concrete is applied with a so-called rebound grid or rebound mesh or the like, which facilitates the construction of a concrete layer and unfurls a reinforcing effect in the concrete layer, the load capacity of lightweight concrete is low.
Therefore, a concrete layer is required on the inside if the tunnel construction must have a proper load capacity. This applies in particular to the distance tunneling of railway tunnels or road tunnels.

For every shotcrete expansion applies:
The structure of the shotcrete construction is facilitated by the priming of the film seal and aids such as rebound mesh / grids, but also by claw mats.
The inventive use of a primer makes in addition to the surface design described above, a contribution to the connection of shotcrete to the film seal and the claw mat.
The primer can be made with the same cement or adhesive or binder that is also used for the shotcrete, but without the benefits provided in the shotcrete.
Cement / adhesive / binder are preferably used in powder form. They are either mixed on the foil surface with water and sprayed or sprayed together with the powdered cement / adhesive / binder before application.

Alternatively, a special primer in the form of a plastic adhesive with mineral admixture proportion is used. The plastic adhesive has a special adhesive effect on the plastic of the film seal and the plastic of the claw mat as well other aids. At the same time, the mineral mixture proportions of the adhesive improve the adhesion of the shotcrete.

The jetting of the primer leads to a thin layer wetting of the film surface and the aids. The layer thickness of the wetting is adjusted so that the primer does not run down by its own weight. In practice, the order quantity is reduced until no run-down is observed. At a constant exit speed of the primer from the application nozzle, the order quantity can be adjusted by changing the solids content. In addition, the primer application can be varied by changing other parameters. The other parameters are the speed and movement of the application nozzle. By movement of the application nozzle, the movement of the nozzle relative to the film seal is meant. Repeated spraying of the film seal at the same place can reduce the order by reducing the repetition of spraying.

Optionally, water-absorbing materials are incorporated into the primer.

After priming, the shotcrete can be applied in a layer or layer or in several layers or layers on the film seal. It is advantageous to apply the shotcrete layer in layers and starting from below. This is achieved by a reciprocating movement of the sprayed concrete application tool. As shotcrete or concrete and additives and aggregates and reinforcing inserts and as tools optionally materials and devices are used, as described for example in the following publications: DE69910173T2 . DE69801995T2 . DE69721121T2 . DE69718705T2 . DE69701890T2 . DE69700205T2 . DE69418316T2 . DE69407418T2 . DE69403183T2 . DE69122267T2 . DE69118723T2 . DE69010067T2 . DE69006589T2 . DE60010252T2 . DE60001390T2 . DE29825081U1 . DE29824292U1 . DE29824278U1 . DE29818934U1 . DE29724212U1 . DE29718950U1 . DE29710362U1 . DE29812769U1 . DE19854476C2 . DE19854476A1 . DE19851913A1 . DE19838710C2 . DE19819660A1 . DE19819148C1 . DE19754446A1 . DE19746958C1 . DE19733029C2 . DE19652811A1 . DE19650330A1 ,

The shotcrete is optionally conveyed dry to the spray nozzle where it is mixed with the necessary amount of water.

The shotcrete is adjusted so that it develops sufficient early strength after impact in a short time. To adjust the shotcrete accelerator can be used, which accelerate the setting of the shotcrete.
Water-absorbing constituents in the shotcrete and / or in the primer also contribute to the formation of the early strength.

Preferably, the tunnel construction is built at the inspection distance from the rock outbreak. This makes it possible to check the condition of the rock outcrop. For example, it can lead to rockfall, which destroys the foil seal and thus creates a leak.
Furthermore, larger rockfalls usually announce themselves earlier by smaller rockfalls. For larger rockfalls, there is a risk of burglary in the tunnel. Inevitably, the tunnel users are also endangered. As a result, regular inspections of the rock excavation and refractory constructions are appropriate. The inspection requires at least partially a walkability of the cavity between the shotcrete construction and the mountain outbreak. The walkability begins at a distance of about 0.4 m between the rock outcrop and the shotcrete expansion. The accessibility is the more comfortable, the greater the distance. Preferably, the distance is limited to 1m for economic reasons.

Distances between the Spritzbetonausbau and the mountain outbreak are known without accessibility for a long time. An example shows the DE 3838630A1 , But there is no accessibility shown.

Alternatively, the film described above is provided on the mountain side with a protective fleece to prevent damage to the film during installation or damage caused by falling stones.

With the shotcrete construction creates a solid concrete shell in a tunnel, which is connected by the anchor with the mountains. However, the tunnel construction is subject to considerable burdens under contemporary load by motor vehicles or train traffic.
This traffic causes strong pressure waves and suction waves. This has resulted in practice that anchor rods of at least 16 mm in diameter, preferably of 20mm in diameter have found use and the anchor rods are arranged in uniform, relatively short intervals.
In addition, the traffic load caused considerable strength of tunnel construction.

All tunnels pose the problem of fire protection.
In every traffic tunnel must be expected with fire. The fire load of a fire can have a significant impact. Under fire load, an inside concrete in the tunnel becomes an additional danger, because the trapped in the concrete water or bound in concrete water is released under appropriate heat and evaporated, so that at the appropriate fire load concrete is blown into chunks. The concrete chunks can develop the effect of projectiles.
In addition, a destruction of the concrete layer can expose combustible components of the expansion, so that the fire can suddenly spread between the expansion of the mountain outbreak.
Therefore, fire protection is provided in most tunnels.

Fire protection is preferably applied refractory material.
Fireproof plates are popular.
The fire protection at the tunnel is very expensive. The invention therefore has the task of reducing the cost of fire protection in the tunnel.

According to the invention, this is achieved in that inside tunnel lightweight concrete is used as fire protection, which consists of concrete and plastic foam particles, being used as plastic polyethylene or polystyrene application. Surprisingly, such lightweight concrete behaves very advantageous under fire load. There is no chipping.
This is attributed to evaporating water readily causing the plastic foam particles to collapse. In the resulting cavities of the steam can escape. The investigations of the fire protection of the invention have shown that even a 60mm thick layer of concrete according to the invention easily holds a fire load of 1000 to 1200 degrees Celsius for 90 minutes and more. Preferably, the thickness is at least 60mm. The thicker the layer, the longer the service life in the event of fire. In time, the tunnel can be cleared.

At the same time, the relatively poor thermal conductivity of the lightweight concrete comes into play. This means that the fire load is only carried slowly into the interior of the lightweight concrete. In the above fire test, the temperature remained so low that a lying behind the fire protection of the invention thermal insulation of polyethylene (PE) as well as the film seal is not compromised.

The use of lightweight concrete, including shotcrete, is known in tunneling itself. However, such a lightweight concrete is regularly found in a layer structure under or behind protective cover layers.

Although it is also a shotcrete with an addition of unfoamed polypropylene fibers known that is free from the risk of chipping concrete parts.
The fibers used are sometimes very fine and have a length of several centimeters. The fibers should melt away in case of heating. As a result, remain in the concrete after heating pores that penetrate the entire concrete. The pores pull moisture.
The moisture causes corrosion.
Such fiber clays are also used without spray application for fire protection.
The DE 4220274 describes the details for a convenient Faserzumischung.
In addition, there is an indication in this document of components made of lightweight concrete with beads of foamed polystyrene. Polystyrene (PS) is a common plastic. Foamed globules are called EPS. EPS is widely used in the packaging industry.
In addition, the production of lightweight concrete has become one of EPS's applications. However, EPS is considered unsuitable for fire safety in this document.
The justification becomes clear from the assessment of other building material with trapped pores. It is assumed that excessive pressure build-up of steam in the pores and this leads to the risk described above.

• Ein ungelöstes Problem beim Einsatz von polymerbasierenden Zuschlagstoffen in Leichtbeton ist die Brandgefahr. Vor allem bei Leichtbeton sehr niedriger Dichte können u.U. Brandschutznormen nicht eingehalten werden. Beim Einsatz in Gebäuden besteht vor allem bei Leichtbeton niedriger Dichte mit Poystyrol-Schaumstoffpartikel als Zuschlagstoff die erhöhte Gefahr der Flammausweitung durch die Wände hindurch und damit die Ausweitung des Brandes über mehrere Räume hinweg.

Still in the DE 10341299 A1 a lightweight concrete with EPS is considered a fire hazard. There it says:

• An unsolved problem when using polymer-based aggregates in lightweight concrete is the risk of fire. Especially with lightweight concrete of very low density fire safety standards may not be met. When used in buildings, especially in lightweight concrete low density with polystyrene foam particles as an additive, the increased risk of flame expansion by the Through walls and thus the extension of the fire across several rooms.

There are no tunnels in which a lightweight concrete with no fire protective top layer has been used.

In addition, in some cases a risk of fire in the processing of plastic foam particles is seen, which could be countered only by flame retardant equipment of the plastic foam particles. Because of the details is on the DE 4428200A1 Referenced.
About the prejudices against the use of lightweight concrete with enclosed plastic foam in fire-prone tunneling, the invention has been ignored.

Optionally, the lightweight concrete used as fire protection in the tunnel has a thickness of 10 to 250 mm, preferably a thickness of 40 to 150 mm, more preferably 50 to 130mm.
The density of shotcrete depends on the amount of EPS particles in the shotcrete. Preferably, the proportion of EPS particles is so large; that results in a density of the applied shotcrete of 300 to 2000 kg per cubic meter. Preferably, the density is 350 to 1200 kg per cubic meter, more preferably 400 to 1100 kg per cubic meter. Conventional shotcrete has a density of about 2500 kg per cubic meter

The size or diameter of the EPS particles is preferably between 0.5 and 7 mm, more preferably between 1 and 6 mm.
The density of the EPS particles is preferably between 10 and 50 kg per cubic meter, more preferably between 20 and 40 kg per cubic meter.

The greater the proportion of EPS particles in the shotcrete, the more difficult it is to have a uniform distribution of the particles in the shotcrete. The EPS particles tend to segregate in the shotcrete. Of the Separation can be counteracted by a surface treatment of the EPS particles. The surface treatment preferably consists of the application of an adhesion promoter. The order of the bonding agent can be done in one or more steps. The use of surfactants as adhesion promoters is known. Because of the details is on the DE 4428200 A1 Referenced.

Optionally, the particles are first wholly or partially coated with an adhesive which is wholly or partially a plastic adhesive, and the EPS particles are then brought into contact with fine-grained mineral material. This is associated with a coating on which a shotcrete easily adheres. In addition, the EPS particles experience a weighting due to the mineral coating, which considerably simplifies the transport of the EPS particles. In addition, the mineral coating counteracts the risk of fire during transport and storage of EPS particles until they are processed in shotcrete.

Optionally, the admixture of the EPS particles is controlled, so that an integral shotcrete is created. A first layer of shotcrete is first applied to an area of the circumference of the tunnel before one or more further layers of shotcrete are applied to the same area. In contrast, the shotcrete technique is to be seen, in which the tunnel peripheral surface is provided with a single shotcrete layer.
The term integral shotcrete is based on the integral foam of the plastic foam technology. The integral foam has less foaming on the outer surfaces than in the middle. When shotcrete according to the invention, the situation is similar, by a higher density of the shotcrete is greater outdoors than in the middle given. At the same time a high thermal insulation effect is maintained in the middle with the high EPS content.

At least two shotcrete layers are preferably provided for the integral technique according to the invention. Particular advantages have three layers, of which the mountain side position and the tunnel inside position by the Interlayer are spaced and have a higher strength, so that the expansion formed by the shotcrete is given a high load capacity.

The thermal insulation of the shotcrete according to the invention should be taken into account in the heat calculation for a tunnel. It leads to a reduction in the thickness of otherwise provided thermal insulation and can make an otherwise provided heat insulation unnecessary.

The edge region / layer of the shotcrete layer designed with greater strength has optionally a thickness of 5 to 30 mm, preferably a thickness of up to 25 mm, from a shotcrete layer total thickness of 50 mm and more. The thickness of the edge region designed with greater strength is preferably dependent on the total thickness of the shotcrete layer. Likewise, reinforcing agents in the edge region or the mountain side and / or tunnel inner side layer influence the thickness thereof. With built-in grids care must be taken to ensure sufficient material coverage of the grid.

The integral shotcrete according to the invention also comprises layers / layers which are applied at intervals.
The integral shotcrete according to the invention also comprises layers / layers of different concretes.
The integral shotcrete according to the invention also comprises differently applied layers and / or differently treated layers.

The strength of the shotcrete can be increased at desired tunnel surfaces, especially in the edge areas / outdoor areas in addition to the fact that the shotcrete is provided with a reinforcement. Preferably, a reinforcement is provided at least to the interior of the tunnel.

The reinforcement may consist of plastic fibers and / or glass fiber and / or carbon fibers and / or steel. As plastic can for example Find polypropylene application. The synthetic fibers should reduce or prevent shrinkage cracks in a fiber concrete. Preferably plastic with high flash point is used.

The plastic fibers can also be added to the shotcrete for fire protection. It is also possible to equip individual shotcrete layers with plastic fibers instead of the plastic particles.
Preferably, the addition of fibers only takes place to increase the strength in the edge region.
At least one amount of fiber of 1 kg per cubic meter shotcrete is preferably added to the shotcrete according to the invention in the intended area, preferably at least a fiber amount of 1.5 kg per cubic meter shotcrete.

When adding fibers of other materials such as glass fibers, it is obviously not intended to melt the fibers in case of fire.
The glass fibers used are preferably alkali-resistant fibers which do not react with the alkalis of the concrete.
Steel fibers can be used in many different ways: stainless, as structural steel, with hooks and without hooks, in various shapes.

Instead of fibers, threads and cords or even metallic wires can be used. It is the same as for the fibers. Reinforcement wires are offered extensively with properties according to DIN 488 with minimum diameters of a few millimeters.

Optionally, mixtures of different fibers come into consideration; both of fibers of different dimensions as well as different other form as well as of different material. Likewise, different mixtures of threads, cords and wires into consideration. Also threads, cords and wires can be mixed with fibers.

Preferably foam particles are provided in each case in the region of the shotcrete, in which without the foam particles there is a risk of spalling of concrete parts. As stated elsewhere, the spalling is due to released water and water vapor.
According to the invention, the vapor is to escape into the cavities, which arise by collapse / collapse of the foam particles under fire load.

For reinforcement also known lattice mats and / or mesh fabric, the tissues may also be made of metal. When using mesh mats or the like made of plastic or glass fibers / threads or carbon fibers / threads are preferably mats with a basis weight of 10 to 500; preferably 50 to 200, more preferably 80 to 150 grams per square meter provided. The basis weight is usually used for the labeling of textiles.

The grid mats made of steel are usually offered as mats according to DIN 488 with minimum wire thickness of a few millimeters, profiled and unprofiled. The reinforcing mats and reinforcing mesh must be placed at a sufficient distance from the edge / outer surface of the shotcrete to cover with concrete. The dimension depends on both the concrete and the reinforcing material.

Optionally, the reinforcement mats and fabrics also come in combination with fibers and / or cords and / or threads and / or wires. Optionally, a reinforcement in shotcrete layers of different density is provided.

Especially in high-strength form the outer skin has a favorable effect on an accident in the tunnel, because the vehicles are steered more in the direction of travel. At the same time, an otherwise yielding core ensures an advantageous damping effect for impacting vehicles in the event of an accident. The high-strength skin has in relation to the core at least twice, preferably at least four times and most preferably at least eight times strength.

At the same time, the reinforcement of the shotcrete layer brings about an advantageous resistance to vibration loading from passing vehicles. For example, shotcrete layers of 140 mm with an approximately centrally arranged reinforced concrete mat (6 mm wire diameter and grids of 150 x 150 mm) and arranged on the outer edge reinforcement made of polypropylene fibers (fiber amount of 2kg per cubic meter shotcrete) even after 5 million load changes with a vibrational load, which is representative of operation in a railway tunnel, has shown no damage.

As explained above, the anchoring technique is particularly suitable for mechanically heavily loaded tunnel construction. Advantageously, the fire protection according to the invention can also be applied if the tunnel lining with the foil seal and the thermal insulation is held by fasteners described above, which are held by nails and other fastening means on a mountain-side shotcrete layer. In this case, fastening means are provided for the reinforcement according to the invention as well as for a desired retention of the applied shotcrete. The fasteners can be formed by a bolt hook and eyelets. Preferably, the bolts, hooks and eyes are provided with a flange or a rondel and this flange in turn can be welded or glued to the film. Welds or splices are preferably selected as the film surfaces which are opposite to the fasteners described above on the films. There, the load from the tunnel extension can be forwarded particularly favorable over the fasteners in the mountains.

Advantageously, the fire protection of the invention can also be used in building construction. With the fire protection according to the invention can be struts, columns, beams, purlins and other supporting parts coated so that a fire, the statics of the building is not affected at least until the building is vacated by people.

A particularly advantageous application is seen in multi-storey car parks, where a vehicle fire at a statically unfavorable place can seriously damage the house.
Likewise, in other buildings fire protection bearing parts of the building with the shotcrete according to the invention is advantageous.

Another advantageous application is seen in rooms where cables and other wholly or partially made of plastic pipes have been laid on ceilings. The fire, which arose at Dusseldorf Airport a few years ago, has shown how quickly a life of devastating smoke can be created through cable and pipe fires. By wrapping these lines with the shotcrete according to the invention that is prevented.
Fire protection in building construction should withstand at least a fire load of 1000 degrees Celsius for 30 minutes, preferably withstand at least 60 minutes so that trapped persons can escape.

For applying the shotcrete is in turn a bonding agent on the components to be protected advantage. The same applies to bolts, hooks and eyes for reinforcing agents and retention means. Cheap adhesion promoters are, for example, the mentioned, mixed with mineral grain size plastic adhesive.

On the fire side, the visible side is regularly on the shotcrete.
It is advantageous if the visible side is provided with a clean layer. This may be a stain-resistant and preferably cleanable paint or plates or sheets or webs or other. The layer of cleanliness is chosen so that it does not pose a fire hazard.

In the drawing, various embodiments of the invention are shown.

Fig. 1 shows a mountain outbreak 1 in stable mountains.

At regular intervals anchors have been introduced into the mountains. For this purpose, appropriate holes were drilled and anchors were fixed with mounting cement in the holes. From the anchors, the central axes 2 are shown.

The mountain outbreak 1 is used to make a tunnel.
For the drainage of the escaping water and to protect against falling stones a shotcrete construction is provided in the mountain outbreak.
The shotcrete construction consists roughly of a film layer 4 and a shotcrete layer 3. The film layer 4 is composed of individual webs, which are laid overlapping and are welded together at the overlapping edges. In this case, two adjacent welds are provided at a distance from each other. The cavity between the welds is pressurized with compressed air to check the tightness of the welds.

Details of the Spritzbetohausbaus are in the Fig. 2 shown.
In this case, an armature 5 is shown schematically. The armature 5 is connected to the protruding end of the mountains with a rondellenartigen fastener 14. At the fastener 14, the film layer 4 is applied.
At the film layer side, which is opposite to the fastener 14 is a fastener 15. The fasteners 14 and 15 clamp the film layer 4 between them.
In addition, the fasteners carry a spacer 13 for a wire mesh 12. The wire mesh 12 has two purposes. It serves to build up the shotcrete layer 3 by preventing the concrete layer rebounding from falling off of the foil layer. In addition, the wire mesh 12 forms a reinforcement for the shotcrete layer.

In the shotcrete construction of the expansion in relation to the form so much weight that the expansion would collapse before reaching sufficient strength without the anchor. The anchors direct the weight of the shotcrete expansion into the mountains.

After solidification of the shotcrete construction, the anchors form a solid composite of the expansion with the mountains.

In Fig.1 and 2 In addition, a shotcrete layer 17 made of lightweight concrete is shown inneinseitig on the shotcrete construction. This layer 17 has a thickness of 40mm. The lightweight concrete consists of conventional shotcrete and a surcharge of EPS. The surcharge is in the exemplary embodiment 10Vol%, based on the total volume of lightweight concrete.
The EPS has a particle size of 4 to 6mm.

Fig. 3 shows further details of the expansion.
Here, the mountain-side fastener, hereinafter referred to as the outside fastener, designated 9. The fastener 9 has a round and curved shape, such as a dome in the embodiment.
On the outside, a threaded tube 8 is welded, opposite (inside) a threaded rod 10 is welded. Between the armature 5 and the fastener 9, an extension rod 7 is provided. The extension rod is necessary because the anchor sits in a mountain ridge and the distance to the fastener 9 must be bridged.
The threaded tube 8 forms on the fastener 9 a nozzle, the threaded rod 10 a mandrel.
The extension rod 7 is screwed into the neck of the Bestigers 9.
The extension rod 7 is connected at the opposite end via a threaded sleeve 6 with the anchor 5. For this purpose, corresponding threads are provided on the anchor end and in the sleeve and on the extension rod.

The 4 and 5 show another embodiment of fasteners according to the invention. The outside fastener is called 20, the inside fastener 21.
With the outside fastener 20, a nozzle 22 is welded. Unlike in Fig. 3 the nozzle 22 is not simply placed on the closed bottom of the fastener, but by a central opening in the Bottom of the fastener 20 performed so that the nozzle 22 protrudes inside a piece. The degree of projection is precisely matched to the nature of two seals 27 and 28, which the in Fig. 4 include film layer designated 26 between them. The measure determines the possible compression of the seals 27 and 28 during the clamping of the film layer 26.
The seals 27 and 28 and the film layer 26 have openings sufficient to be pushed over a protruding as a mandrel threaded rod 23 and the protruding pipe 22.

Unlike in Fig. 3 the nozzle 22 is provided at each end with a blind hole. Both blind holes are separated by a material wall. In the film-side blind hole, the threaded rod 23 sits as a mandrel.
In the opposite, outside blind hole sits in the installation situation of the anchor.
The described material wall prevents leakage through the thread.

The seals 27 and 28 are in the embodiment of polyethylene foam with a density of 30 kg per cubic meter, in other embodiments of 18 to 40 kg per cubic meter. The purpose of the seals is to compensate for unevenness in the surfaces of the fasteners and the film and imbalances between the fasteners. The thickness of the seals is 5mm, in other embodiments 3 to 10 mm. By tightening the two fasteners experienced the seals a strong compression, so that the density of the seals comes close to the density of non-foamed polyethylene.
The thickness of the seal is reduced by bracing the two fasteners to at least 50%, preferably to at least 70% and even more preferably to at least 90%. The reduction refers to the foam volume. In this consideration, the volume of unfoamed film remains the same plastic and the same basis weight unconsidered. That is, the initial dimension relevant to the thickness reduction is reduced by the thickness of the unfoamed film.

In a further embodiment, the seals are self-adhesive on both sides. The adhesive surfaces are covered by silicone-coated paper before assembly. The paper is first peeled off the contact surface with the fastener 20. Thereafter, the seal 28 can be positioned and pressed on the fastener 20. Subsequently, the paper is withdrawn from the contact surface of the seal 28 with the film layer 26 and pressed the film layer against the seal. This results in a provisional stop of the film seal 26. For further assembly, the paper is withdrawn from the contact surface of the seal 27 with the film layer 26 and the seal 27 is positioned and pressed against the film layer 26.
Thereafter, the paper is withdrawn from the contact surface of the seal 27 with the inner fastener and the fastener 21 is pushed onto the mandrel. The fastener 21 has an opening that is slightly larger than the diameter of the threaded rod 23 but at the same time significantly less than the diameter of the nozzle 22.

After pushing the inner fastener results in the Fig. 5 illustrated situation. In the situation, no pressure is exerted on the seals. The seals have the shapes and thicknesses designated 27 'and 28'.
By means of a nut 25, the fasteners 20 and 21 are compressed so far that the seals develop a desired pressure against the film layer on the one hand and against the contact surfaces with the fasteners on the other.
This pressure also causes a clamping of the film layer. Together with the adhesive connection results in a very advantageous holding the film layer.

Fig. 6 shows a further embodiment for the fastener.

The fasteners are designated 30 and 31. The two fasteners 30 and 31 enclose a film layer 32 between them.
Unlike the embodiment according to Fig. 3 to 5 the outside fastener 31 is provided with a pot-like recess. The inside fastener 30 is like a lid in the pot-like fastener 31, so that between the curved edges a desired clamping takes place. In this case, inclined surfaces act like wedges against each other, so that with little force over appropriate ways a strong clamping, even a large-scale clamping can be achieved.
In order to avoid injury to the film, the fastener 31 is also provided with a curved edge 33.

Fig. 8 shows a possible honeycomb 43 for the in Fig. 2 illustrated wire mesh.

Fig. 7 shows a spacer 40 for the positioning of the wire mesh. The spacer 40 is pressed with another nut against the nut 25.
The spacer 40 has various arms to which the wire mesh 43 can be hooked.

Fig. 9 shows a conventional outside fastener 40 with a central continuous thread and with an adapter 42. The adapter 42 has a mandrel 41 with an external thread. Opposite the mandrel 41, the adapter 42 has an outer diameter which corresponds to the diameter of the integrally formed neck 44 on the fastener 40. The adapter 42 is screwed with its mandrel 41 in the fastener 40, that the adapter 42 closes against the nozzle 44 and the two contact surfaces are stretched against each other. Both contact surfaces are processed so that leakage is excluded. Optionally, the seal is additionally secured by a sealing ring 45.
On the outside, the adapter 42 has a threaded hole formed as a blind hole 43, with which a screw on the anchor is possible.

Fig. 10 also shows a conventional outside fastener 50 with a central continuous thread. This fastener is combined with a mandrel 51 having a collar 52 and a part 53. With the part 53, the mandrel has been screwed from the inside through the fastener and screwed into a threaded sleeve 54 described above for extension operations. In this case, the collar 52 is closing against the fastener 50 and the threaded sleeve 54 is closing against the stub 57 of the fastener.
The contact surfaces are the same as after Fig. 9 processed. Further, a seal 56 is provided between the collar 52 and the fastener 50.

The embodiment according to Fig. 11 differs from the embodiment according to Fig. 4 in that, instead of the connecting piece 22, a connecting piece 61 with a continuous threaded bore is provided.
The nozzle 61 is seated like the nozzle 22 on the designated anchor end 71. The threaded rod 60 is like the threaded rod 23 in the socket 61. Between the threaded rod 60 and the armature end 63 is a plug 62 made of plastic, nylon in the embodiment, in other embodiments of polyamide.
The plug 62 undergoes a compression between the armature end 63 and the threaded rod 60, so that the plastic deforms sealingly into the threads.

Fig. 12 shows a further embodiment with a nozzle 70 with an anchor end 71 and a threaded rod 72. Instead of a plug 62 a plurality of plugs 73 and 74 are provided.
The plug 73 has a basic length or standard length, the plug 74 has a significantly smaller special length or adjustment length. The plugs 74 serve to adapt to greater distances of the anchor end 71 from the center of the tunnel. The larger distance, however, is not so great that an extension rod is economical, as in Fig. 3 is shown.

Fig. 13 shows an embodiment with a nozzle 80, which differs from the nozzle 61 in that inside a groove 82 has been incorporated. The groove 82 has a depth which is greater than the thread depth of the thread. As a result, the surface is smooth in the groove bottom and can cause the threads no leakage.
In addition, annular grooves are incorporated in the groove bottom.
Upon compression of the plug, the plug deforms into the groove 82 and into the grooves 83.

The groove 82 and the grooves are easy to turn.

FIGS. 14 and 15 show a shotcrete construction for a tunnel in stable mountains. The mountains are designated 101. In the mountains threaded rods 102 have been introduced as an anchor. 101 holes have been drilled into the mountains and the anchors have been glued in the mountains. The anchors are placed at a distance of 1.2m in such a way that a large number of uniform attachment points are created at the circumference of the rock outcrop, and all points lie on the corner points of equal squares with an edge length of 1.2 m.

On each threaded rod 102, a sealing washer 103 has then been screwed. Then a waterproofing membrane has been laid. The laying is done in such a way that the film has been placed on the protruding anchor. The anchors 102 penetrate the film. The resulting holes are closed by means of further sealing discs 105. The sealing discs 103 and 105 clamp the film 104 between them and moreover close tightly with the anchors 102.

In Fig. 18 is a suitable film for the shotcrete construction shown. The film 110 has a thickness of 2 mm and is sprinkled with strands of material, the strands of material 111 have a thread-like structure with a thickness or diameter of 0.1 to 0.3 mm and a length of 5 to 50 mm.

The material strands 112 have a thickness of 1 to 2 mm and a length of 10 to 30 mm.
The different material strands are applied in the exemplary embodiment in separate application operations in order to heat the material strands with a larger diameter differently than the material strands with a smaller diameter.
In other embodiments, the strands of material are applied in a common application process.
The material strands are superimposed on each other, so that in part there is a hollow layer of the material strands. In this situation arise with the material strands 112 surveys up to a height of 3mm.
In part, the film surface is uncovered.
The material spread has a basis weight of 250 grams per square meter. It may also occur in other embodiments, larger or smaller basis weights. Lower basis weights may occur in particular if the film surface is additionally profiled. Thus, basis weights of, for example, 20 grams per square meter are possible.
Larger basis weights are appropriate if, depending on the type of shotcrete contract difficulties are to be overcome.

The different strands of material are sprinkled in the embodiment after heating on the surface of the previously superficially heated film 10. The superficial heating of the strands of material has taken place up to the molten liquid.
The heating is carried out by radiation by the material strands are removed by means of a rotary valve from a reservoir and fall through a heating channel down to the slow slow down past slide. The heating channel has in the exemplary embodiment a plurality of electrically operated heating wires and a temperature control.
As a result, the temperature of the heating channel can be increased until the falling material strands have the correct surface temperature.

After installation of the film 104 in the tunnel, in the exemplary embodiment, first a fast-binding cement milk is sprayed thinly onto the film. The dried cement slurry forms an advantageous primer for a subsequent application of shotcrete. The shotcrete is applied in layers, starting at the tunnel sole. The resulting shotcrete layer is designated 106.
In the exemplary embodiment, the tunnel runs horizontally, so that the shotcrete is laid in horizontal layers, which are laid übereinander from bottom to top of the film. The layers have a width which corresponds to the desired shotcrete layer thickness.
In other embodiments, a smaller width of the layers is provided, so that first a first shotcrete layer is applied to the film, which completely covers the film side. Thereafter, another shotcrete layer is applied, which completely covers the previously discussed shotcrete layer. This is repeated until the desired thickness of the shotcrete layer is reached.

After creating the shotcrete layer, the anchors still protrude from the concrete layer. Another shotcrete layer 109 has been applied to the shotcrete layer 106. The further shotcrete layer 109 is made of lightweight concrete and serves as in the exemplary embodiment Fig. 1 and 2 as fire protection. The further shotcrete layer 109 adheres to the shotcrete layer 106. In addition, the protruding from the shotcrete layer 106 ends of the anchor should cause an additional connection with another shotcrete layer 109.

Fig. 16 shows a shotcrete construction for another tunnel in stable mountains 115. To the shotcrete removal includes a film 117 as in the expansion after Fig. 14, 15 and 18 and a shotcrete layer 116.
Unlike the embodiment according to FIGS. 14 and 15 However, the anchors are made very short and attached to the protruding anchor ends so-called rondels. The rondels are plastic discs, with where the film 117 is welded in the embodiment. In other embodiments, a bonding takes place.
In this construction no perforation of the film takes place.
In addition, the anchor ends are so short that the rondelles have contact with the mountain outbreak as far as possible. This is achieved in the embodiment in that the rondels are already mounted on the anchors when the anchors are placed in the holes. The anchors are then pushed into the boreholes until the rondels abut the rock outcrop. In the drill holes is a mounting mortar / cement, which encloses the anchors and sets after hardening in the wells. Advantageously, when applying the shotcrete to the film 117 at a variety of other locations, a contact between the film and the mountain outbreak instead, because the injection causes a buckling of the film in the direction of mountain outbreak.
The contact facilitates the molding, because the film can not vibrate there and the shotcrete can not throw off there.

The contact between the mountain eruption and the expansion also has the great advantage that erupting stones invest only slightly in the expansion, while falling down at a spaced expansion and meet with considerable momentum on the expansion.

Such contact can also be with the anchors and fasteners of the previous embodiments, in which the mountain-side fastener is mounted on its anchor, that he has contact with the mountain outbreak.

Fig. 16 also shows another shotcrete layer 121 on the inside of the expansion. It is a fire protection as in the previous embodiments.

Fig. 17 shows yet another embodiment of an expansion, in which also a contact between expansion and mountain outbreak is made. In this case, first a shotcrete layer 119 to Sealing / consolidation applied to the mountain eruption. Subsequently, a nonwoven layer 120 is applied to the shotcrete layer 119. This is done with simultaneous nailing of rondels 118. The nailing is easy as long as the shotcrete layer is not yet cured. But even then a nailing with appropriately hardened and stable nails is possible. In addition, the rondels can also shoot.
On the mounted rondels a film 117a is welded, as in the embodiment according to Fig. 16 explained. In addition, the same shotcrete layer 116a is as in FIG Fig. 16 intended. The same applies to the inside further shotcrete layer 122 made of lightweight concrete.

Fig. 19 shows a tunnel construction with a film seal 151 of PE with a thickness of 1.5 mm, a 35 mm thick PE foam layer 152 as a thermal insulation, a 60 mm thick EPS shotcrete layer 154 and a cleanliness layer 153 in the form of a flame-retardant paint. The shotcrete layer has a density of 900 kg per cubic meter.
The shotcrete layer is fiber-reinforced in the area 155. The reinforcement is glass fibers in an amount of 2 kg per cubic meter shotcrete.
The expansion is held by schematically illustrated anchor 150.

Fig. 20 shows a tunnel construction with a film seal 141 made of PE with a thickness of 1.5 mm, a 70 mm thick EPS shotcrete layer with a density as in the embodiment according to Fig. 19 and with a reinforcement of structural steel mesh 144. This expansion is also held with anchors 140 shown schematically.
On the inside of the tunnel of the shotcrete layer 142, a clean layer 143 is provided.

In fire protection tests, the fire protection layer according to the invention behaves as follows:
The fire load is in Fig. 21 shown. The fire load has been measured at 8 points, which have heated uniformly within a few minutes to 1100 degrees Celsius. The curve is labeled 160.

The Fig. 22 shows the temperature at 6 measuring points within the shotcrete layer Fig. 20 , The measuring points are arranged at different distances from the burning area. The most remote from the fire surface measuring point shows over a period of 2 hours no significant increase in temperature. This is designated 161.

Claims (24)

Fire protection for buildings, a) for tunnels or the like, preferably for tunnels in stable mountains, b) with a seal against water, in particular in the form of a film, c) where anchors are used, cc) in particular anchors which are introduced into the mountains and hold the further tunnel construction, ccc) or where fasteners are used, which are introduced into a mountain-side shotcrete layer and hold the further tunnel construction, e) wherein a shotcrete layer is provided on the inside of the tunnel, f) characterized by a lightweight concrete as shotcrete and fire protection, which consists at least in part of Kunststoffschaümpartikeln and holds a fire load of at least 1000 degrees Celsius for at least 90 minutes, or g) for buildings with risk of fire parts such as beams and columns and spritzweise applied fire protection h) characterized by a shotcrete fire protection, which consists at least in part of plastic foam particles and a fire load of at least 1000 degrees Celsius for at least 30 minutes, preferably at least for 60 minutes, stops. Fire protection according to claim 1, characterized in that the shotcrete has a density of 300 to 2000 kg per cubic meter, preferably 350 to 1200 kg per cubic meter, even more preferably 400 to 1100 kg per cubic meter. Fire protection according to claim 1 or 2, characterized by a thickness of 10 to 250 mm of the inside lightweight concrete layer, preferably a thickness of 40 to 150, more preferably 50 to 130 mm, in particular a thickness of at least 60mm for use in tunnels. Fire protection according to one of claims 1 to 3, characterized by EPS particles with a bonding agent on the surface Fire protection according to Claim 4, characterized in that the EPS particles are coated wholly or partly with an adhesive on the outside, to which mineral particles adhere. Fire protection according to claim 5, characterized in that the adhesive is wholly or partly a plastic adhesive and / or the mineral particles are fine-grained. Fire protection according to one of claims 1 to 6, characterized by a multi-layer shotcrete layer, with different EPS particle content in different layers and / or by different concrete properties in different layers and / or by different particle properties in different layers. Fire protection according to claim 7, characterized in that the volume weight of the shotcrete layer to the mountain-side edge and outer surface and / or the tunnel inner side edge and outer surface is higher than in the shotcrete layer center. Fire protection according to claim 7 or 8, characterized by an inside shotcrete layer as a cleanliness layer, which is free of EPS particles and / or a clean layer of an at least flame retardant paint and / or an at least flame retardant textile and / or from an at least flame retardant web and / or at least flame retardant plates. Fire protection according to one of claims 7 to 9, characterized in that the shotcrete layer on the mountain side edge or outside and / or on the tunnel inside edge or outside has a higher strength. Fire protection according to one of claims 7 to 10, characterized in that the edge region of higher strength has a thickness of 5 to 30 mm, preferably a thickness of up to 25 mm. Fire protection according to one of claims 1 to 11, characterized in that the shotcrete is provided with a reinforcement. Fire protection according to claim 12, characterized by a reinforcement with fibers and / or threads and / or cords and / or wires and / or fabrics and / or mats, in particular made of tree slats or mesh fabrics, preferably with a fiber weight of 1kg per Cubic meter, even more preferably with a fiber weight of 1.5 kg per cubic meter. Fire protection according to claim 12 or 13, characterized in that the reinforcement consists of plastic and / or glass and / or steel and / or carbon Fire protection according to claim 13 or 14, characterized in that the plastic fibers are made of polypropylene and / or glass fibers are alkali-resistant and / or the Stah1 is stainless and / or provided with hooks. Fire protection according to one of claims 12 to 15, characterized in that the mats and fabrics have a basis weight of 10 to 500 grams per square meter, preferably 50 to 200 grams per square meter, more preferably 80 to 150 grams per square meter. Fire protection according to one of claims 12 to 16, characterized by the simultaneous use of different reinforcing forms and / or different reinforcing materials and / or differently treated reinforcing materials Fire protection according to one of claims 7 to 17, characterized by a fire-side layer of the shotcrete having in relation to the center of the shotcrete at least twice the strength, preferably 4 times the strength and most preferably at least 8 times the strength. Fire protection according to one of claims 12 to 18, characterized in that the reinforcing mesh and / or mats also serve as retention during the application of the shotcrete. Fire protection according to one of claims 1 to 19, characterized in that the anchors protrude into the shotcrete layer. Fire protection according to one of claims 1 to 19, characterized by an adhesion promoter on the struts and columns of the building construction for the application of the shotcrete and by fastening means for reinforcing agents and / or for the retention of sprayed concrete. Fire protection according to one of claims 1 to 21, characterized by a shotcrete application to exposed lines and plastic parts in rooms of building construction. Fire protection according to one of claims 1 to 22, characterized by the use of EPS as admixture proportion for the lightweight concrete. Fire protection according to Claim 23, characterized in that the EPS has a particle size of 0.5 to 7 mm, preferably 1 to 6 mm and / or the foam particles have a density of 10 to 50 kg per cubic meter, preferably 20 to 40 kg per Own cubic meters.

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