EP0178345A1 - Surfacing for bridges with prestressed, reinforced or composite concrete decks - Google Patents

Abstract

1. Asphalt based surfacing for bridges with decks of concrete, consisting of the actual surface coating (a) of mastic asphalt or asphalt concrete, an asphalt based protective layer (b), similarly predominantly of mastic asphalt, and a subsequent sealing coating (g) which forms the transition to the concrete surface (e), and which is made up of a bituminous sealing course, characterized by the fact that the sealing course (g) is developed as a sheet which displays a coating (j) of metal, in particular of aluminium of stainless steel, or a polymer plastic which remains stable beyond the liquefaction temperature of bitumen, which is perforated or punched, whereby the perforation of holes (1) amount to between 1 and 25 %, in particular between 5 and 10 % of the total surface of the coating, the individual holes (1) are arranged primarily in a random orientation, and the holes (1) have a mean diameter of 0.01 to 1 mm, in particular 0.1 to 0.5 mm.

Description

The invention relates to a bituminous covering for bridges with superstructures made of concrete, in particular prestressed and reinforced concrete, consisting of the actual surface layer (layer exposed to traffic) made of poured asphalt or asphalt concrete with a thickness of 35 mm, a protective layer made of poured asphalt from under the surface layer also ^y 35 mm thick and a sealing layer of about 4.5 mm thick, the z. B. can consist of a welding track with a carrier insert, the bitumen content in the welding track can be between 60 and 100 wt .-%.

Road surfaces for concrete bridges of the type mentioned above are known and have long been used in practice.

In addition to the actual top layer of cast asphalt or asphalt concrete, which is directly exposed to traffic, the so-called sealing layer is of particular importance for such bridge coverings, because it mediates the transition between the thermally and mechanically flexible top layer and the rigid concrete superstructure of the bridges.

Basically, the concrete of the bridge superstructure is provided with a seal, which usually has an additional separating layer. This has the task of absorbing or preventing the swelling and bulging when the volume increases, due to moisture evaporating from the concrete, by expanding air and other gases when the temperature rises.

A glass fleece, which is applied directly to the concrete surface, generally serves as the separating layer. This separation layer is then followed by a layer of asphalt mastic of the thickness mentioned above. For a given bitumen content, additions of fillers are common, so that one from sufficient strength against the heat of the mastic asphalt as a protective layer and the mastic asphalt or asphalt concrete as a final top layer is guaranteed.

In the course of the development of coverings for concrete bridges, it has proven advantageous to use so-called metal corrugated strips, for example made of aluminum or copper or stainless steel, in addition to, or instead of, the asphalt mastic. First, a primer, for example on a bituminous basis, is applied to the cleaned and dry concrete surface with about 0.25 to 0.40 kg / m ² bitumen solution. This is followed by a separating layer made of perforated glass fleece bitumen membrane, the purpose of which is, among other things, to relieve the pressure of vapors and gases. The metal corrugated tapes are then glued to this, in particular in the pouring and rolling process using an adhesive, for example made of bitumen filled with slate flour or fibrous materials. The subsequent protective layer consists of pure mastic asphalt. In a further development, prefabricated bituminous welding sheets are used instead of the casting and rolling process or adhesive process, the surfaces of which are metal and plastic laminated. In these cases, the perforated glass fleece bitumen membrane is dispensed with and the sealing membrane is flamed onto the bitumen welding membrane on the concrete surface provided with plastic and / or bituminized primer.

The occurrence of bloating and thus the formation of overpressure areas, caused by moisture and air, hydrocarbons etc. enclosed and evaporable in the concrete, cannot always be prevented even with the best possible application of the hot seal (sealing, protective and cover layer).

The with temperatures of over 200 ⁰ Q on the metal base made of corrugated tape, for example with calotte corrugation bituminous protective layer leads - often spontaneously, but often also over measurable periods - to a considerable expansion of the volatile or evaporable components contained in the concrete, which subsequently exert considerable pressure loads on the closed metal foil. In the case of corrugated metal foils, the pressure can be distributed in the direction of the corrugation, but pressure relief is not possible.

Finally - and this is also of crucial importance for the strength and durability of the entire covering structure - when the heat is transferred from the hot mastic asphalt to the relatively cold concrete, the expansion of volatilizing gases and vapors loosens the layer structure. This process is in most cases declining after cooling, but the defects that have occurred, e.g. Cracking and blistering, as well as a lack of layers in the protective and sealing layer, sometimes also in the top layer, are so serious that they can only be remedied by the often complete removal of the bridge covering and renewed application.

In this context, reference is made to the German utility model 83 36 945.7, which is to be regarded as a technological background.

In the course of studies on the practical avoidance of the effects and disadvantages dealt with above when using metal foils, in particular metal corrugated tape for the construction of bituminous coverings on concrete, in particular for the construction of the sealing of coverings on bridges made of prestressed, reinforced or composite concrete, there has now been Surprisingly, it was shown that by simply perforating or perforating the metal foil, at the moment of application of the hot Mastic asphalt to form the top and protective layers on the sealing layer-concrete system creates a quick pressure equalization, which reduces the risk of; Formation of overpressure areas by volatile components evaporating from the concrete or expanding air under the metal foil is completely avoided.

Associated with this, the metal foil itself is not subject to any mechanical stress due to excess pressure, so that the risk of reducing the. Layer composite, cracks, bubbles, etc. is fixed. The sealing effect of the sealing and protective layer forming the seal is thus also fully retained.

The invention thus relates to a bituminous covering for superstructures made of concrete, in particular prestressed and reinforced concrete, consisting of the actual top layer of cast asphalt or asphalt concrete, the bituminous protective layer and a sealing layer forming the transition to the concrete with metal foil, characterized in that the metal foil is a Perforation or perforation, which is between 1 and 25%, in particular between 5 and 10% of the total surface of the metal foil, the individual, predominantly statistically distributed perforations having a diameter of 0.01 to 1 mm, in particular, especially 0.1 up to 0.5 mm.

In the context of the invention, the term metal foil is understood to mean both smooth and structured foils, plates, strips, etc., as will be shown later.

Aluminum and stainless steel are particularly suitable as the metal or material for the film, although copper and similar non-ferrous and light metals are also suitable.

In the context of the invention, the term structured encompasses those configurations which have elevations protruding from the plane. Examples of this are corrugations, corrugations, nubs of any geometric habit (squares, rectangles, cones, hemispheres, paramids, etc.).

The thickness of the metal foil, in the place of which plates or strips can also be used, is between 0.05 and 1 mm, in particular between 0.10 and 0.3 mm (wall thickness). It has been shown that instead of metals, thermally stable up to the temperature of the hot mastic asphalt (for top and protective layer) stable high polymers, such as hard PVC, post-chlorinated PVC, polyethylene, polytherephthalic acid esters, polyacrylates, etc., as well as corresponding copolymers with two and more types of monomers are quite suitable. Occasionally, however, certain deviations from the wall thickness of the ranges specified above are necessary in order to ensure sufficient compressive strength for a given coefficient of thermal expansion. In general, the wall thicknesses of polymers and copolymers are up to 100% larger than that of aluminum or stainless steel.

The size of the free, that is to say volatile constituents of the concrete, which is formed after the perforation or perforation in the film forming the sealing layer, be it from metal or from a polymer or copolymer material, is generally about 1 to 25% of the total area the film that faces the protective layer. Below approximately 1%, the pressure compensation behavior of the film is considerably restricted and can only be used to a limited extent, while above approximately 25% the mechanical stability of the film is endangered. Especially when using metals such as aluminum or stainless steel, the upper areas of the free area quite acceptable, while the lower limit values are more important for plastics. However, it is generally pointed out that this criterion results from area-wide tests, so that there is no absolute restriction on material and perforation area. In general, open areas between about 5 and 10% of the total surface area of the film are preferred.

The size of each hole, i.e. their diameter, ranges between 0.01 and 1 mm and is directed among other things also according to the mechanical strength of the film material. In the case of perforations in the lower size range, the number of perforations per unit area is generally greater than in comparison with perforations of large diameter or opening cross section.

The arrangement of the perforation or perforation is generally and preferably statistical, i.e. there is an even distribution over the entire surface facing the protective layer.

The geometrical shape of the perforations can be of any type, although a circular habit is preferred for reasons of simple manufacture (drilling or punching). However, other shapes such as squares, rectangles, polygons, slots, etc. are also suitable. The simplest form of the perforated film can occasionally also be formed by a fabric, the mesh size of which determines the free area which allows volatile components to pass out of the concrete.

In addition to the pressure equalization behavior already discussed at the outset when applying the hot bituminous layers to the sealing layer, the perforations or perforations in the film have a further, not inconsiderable advantage, which consists in the fact that in Area of the perforations, hot bitumen from the overlying protective layer can penetrate into the film and / or from the welding path into the overlying protective layer and, after cooling, leads to a highly stable anchoring between the protective layer on the one hand and concrete on the other hand, the film itself being fixed in its position, so that there is continuous stabilization of the entire covering.

From this effect of the perforation or perforation of the film, the great importance of the latter is further reinforced. First, the perforations in the metal or polymer film are open, which means that when the hot mastic asphalt is applied, the volatile substances contained in the concrete can escape without hindrance.

If the mastic asphalt has cooled, the perforation is closed - by bitumen flowing in - to the anchorage described above.

A further advantage, particularly with regard to the stability and the cohesion of the covering, are the fragments remaining when punching out or pressing out the perforations from the film material and still connected to the film surface, the ends of which, like a grater, after application of the mastic asphalt Protective layer protrude into the mastic asphalt (protective layer). Such upward fragments at the edge of the perforations not only lead to a directed passage of the volatile components from the concrete through the perforations, they also form an additional anchoring of the foil, which in this case is made in particular of metal, in the protective layer.

The invention is explained in more detail below with reference to FIGS. 1-6.

• Fig. 1a und 1b den Aufbau bitumenhaltiger Beläge mit Überbauten aus Beton, wie sie nach bisher üblicher Weise erstellt wurden.
• Fig. 2a und 2b den Aufbau derartiger Beläge gemäß der Erfindung.
• Fig. 3 einige beispielhafte Möglichkeiten der Folienlochung und des Folienaufbaus gemäß der Erfindung.
• Fig. 4 und 5 die verankernde Wirkung der erfindungsgemäßen Perforierung der Folie.
• Fig. 6 die Perforierung bzw. Lochung in Riffel- und Noppenbahnen.

Show it:

• 1a and 1b, the construction of bituminous coverings with superstructures made of concrete, as they were created in the usual way.
• 2a and 2b the structure of such coverings according to the invention.
• 3 shows some exemplary possibilities of film perforation and film construction according to the invention.
• 4 and 5 the anchoring effect of the perforation of the film according to the invention.
• Fig. 6 shows the perforation or perforation in corrugated and knobbed sheets.

According to FIG. 1 a, the hitherto customary construction of a bituminous covering for superstructures made of concrete initially consists of the cover layer (a) made of poured asphalt or asphalt concrete, followed by the protective layer (b), preferably also made of guasphalt, which can also also serve as a seal, the sealing layer, preferably made of asphalt mastic (c), a separating layer (d) made of raw glass fleece and then the concrete (e) of the bridge board. This version does not use a foil-containing (metal or plastic) sealing layer.

Different with the structure according to Figure 1b. Here too, the top and protective layers (a, b) correspond to the known structure. This is followed by a bitumen welding sheet (f) with laminated aluminum foil, the welding sheet (f) possibly being glued over the entire surface of the concrete of the bridge panel (e) using a primer. In this context, it should be recalled that, especially in the construction according to FIG. 1b, it is not possible for volatile components in the concrete to escape when the hot mastic asphalt is applied, since the aluminum foil provides a perfect seal. This also applies if the aluminum foil is structured, So for example as a corrugated or No ^pp en film is formed. A passage of pressure-increasing gases and vapors through the welding path remains blocked.

FIG. 2a shows a first embodiment of the covering structure according to the invention. Cover and protective layer (a, b) are again largely identical to the corresponding layers according to FIGS. 1a and 1b.

However, the sealing layer or welding track (g) is provided with a film covering which has a statistically distributed perforation (j). In the simplest case, this is an unstructured film, plate or tape, e.g. made of aluminum, stainless steel or plastic, the statistical hole distribution of e.g. Embossing, punching or drilling was obtained. The sealing layer or welding track (g) lies on the concrete (e) with the application of a primer (h) made of bituminous adhesive or a plastic adhesive over the entire surface.

FIG. 2b shows the structure according to the invention of a covering with structured film (j) and additional separating layer (k) made of raw glass fleece. The film (j), in the special case made of aluminum or stainless steel, is constructed in the manner of a corrugation or knot, in which the perforations are provided exclusively in the elevations or knot surfaces.

It should be noted here that FIGS. 1a, 1b, 2a and 2b only show the covering structure schematically, that is to say that both material from the protective layer (b) and from the raw glass fleece (k) intervene in the existing empty spaces above or below layers .

The simplest form of the perforated or perforated film is shown in FIG. 3a. This is a flat, non-structured surface (j) with statistically distributed perforations, mainly of the same diameter.

As Figure 3b shows, the perforation can also have other geometric shapes and e.g. be conical (1).

It has already been said at the beginning that it is particularly advantageous if the material fragments which arise when printing out or punching out the perforations from the foil material (this applies preferably to metallic foils) are retained at the edge of the respective perforation, since this creates an additional anchoring process. This is shown schematically in FIG. 3c. The fragments (3) from the bores (1) point upwards and thereby engage in the material of the protective layer (b) - see FIGS. 2a and 2b - with the formation of anchoring zones. The same effect is achieved in maintaining the ridges down.

A structured, perforated film according to the invention is shown in FIG. 3d. This is a corrugated or knobbed sheet, the uppermost surface areas of which have the perforation (1) according to the invention. However, the perforation is not limited to the flat or horizontal areas (3) of the knobs, it can also be carried out - alone or in addition - in the inclined surfaces as long as they are in the space above the film (j), i.e. in the direction of the protective layer (b) - see FIG. 2b - opens out. It is understood that dimpled sheets of this type are not bound to the geometry of FIG. 3d. The upstanding knobs (3) can be larger or smaller than the remaining floor areas. Knobs of different sizes can also alternate with one another distributed over the film surface.

The anchoring effect of the perforations is particularly apparent from FIGS. 4 and 5. When the hot mastic asphalt is applied to the sealing layer, which is designed, for example, as a welding track (g) with metal foil (j) and raw glass fleece (k), which is primed (h) with the concrete (e) liquid bitumen (4) from the protective layer (b) enters the perforations (1) of the film (j) and fills the perforations (4 '). However, the bitumen can also penetrate into the fleece (k) or another suitable carrier insert (4 "), so that a continuous anchoring between the protective layer (b) and concrete (e) after the bitumen (4, 4 ', 4 ") given is. Since the cooling process of the bitumen takes place with a time delay, the evaporating volatile constituents in the concrete are given sufficient opportunity to escape before the bitumen solidifies.

This anchoring process is intensified if, as shown schematically in FIG. 5, the fragments discussed above in connection with FIG. 3c are retained at the edge of the perforation. These material fragments (2) form an upward and / or downward exit for the volatile constituents in the concrete and ensure additional, particularly firm anchoring of the film and thus of the entire sealing layer.

Finally, FIG. 6 shows a particularly advantageous embodiment of the corrugated or nubbed sheets according to the invention as part of the sealing layer, in particular if this is designed as a welding sheet.

Any geometric shapes can be formed, which are based on parallel to FIG. 6b of parallel corrugations or, according to FIG. 6a, are made up of knobs arranged offset to one another. Here, too, the perforations (1) are not bound to the uppermost (flat or horizontal) surfaces. They can also be provided in the side surfaces (3, 3a, 3b) and e.g. be designed as slots.

The anchoring process of the liquid bitumen penetrating through the perforations (1) can also be seen from FIG. This not only fills the gaps (7) - partly as mastic asphalt from the protective layer (b) - it also penetrates into the possibly lower hollow areas (6) of the dimpled sheet (j) and thus conveys the overall effect, such as it was dealt with above with reference to FIGS. 4 and 5. Of course, mutual effects occur in films with bituminous welding sheets.

In conclusion, it should be noted that the use of the covering structure according to the invention for concrete (bridges) made of perforated or perforated metal or plastic film in the area of the sealing layer (asphalt mastic plus (if necessary) glass fleece and film) in a long-term test as absolutely reliable and all over a long period previously known disadvantages of such coverings has been remedied. The damage spots in the road surface that have been repeatedly observed up to now, caused by burst steam or gas bubbles, especially shortly after the application of the bituminous cover and protective layers, no longer occur. A rise in pressure in the area of the seal is no longer observed. The surface is absolutely firm.

For practical use it is also important that factory-made systems made of bituminous welding membrane and perforated foil, in particular metal foil, i.e. the entire sealing layer (e.g. according to (g), Fig. 2a and 2b or (g) Fig. 4 and 5) on site to the concrete surface pretreated with a bituminous adhesive or a plastic adhesive (see (h), Figures 4 and 5) can be applied in the so-called flame process. Individual sheets of perforated film and seal according to the invention Material, for example based on bitumen or a mixture of other binders, is solidified by overlapping and welding on the adhesive coating (h) and thus on the surface of the concrete (e).

Claims (12)

1. Bituminous covering for superstructures made of concrete, in particular prestressed and reinforced concrete, consisting of the actual top layer of poured asphalt or asphalt concrete, a bituminous protective layer, mainly also of poured asphalt, and a subsequent sealing layer forming the transition to the concrete surface, characterized in that the sealing layer consists of a bituminous sealing sheet, possibly reinforced by a carrier insert, which has a smooth or structured layer, designed as a film, plate or sheet, which is perforated or perforated, the perforation or perforation being between 1 and 25%, in particular is between 5 and 10% of the total surface of the insert, the individual holes are arranged predominantly in a statistically distributed manner and the holes have an average diameter of 0.01 to 1 mm, in particular 0.1 to 0.5 mm. 2. Bituminous covering according to claim 1, characterized in that the support is made of metal, in particular aluminum or stainless steel. 3. Bituminous covering according to claim 1, characterized in that the support is made of a polymer polymer which is stable up to the liquefaction temperature of bitumen. 4. Bituminous covering according to claims 1-3, characterized in that the support is a wire mesh. 5. Bituminous covering according to claims 1-3, characterized in that the holes are circular, conical, square, polygonal or slit-shaped. 6. Bituminous covering according to claims 1-3, characterized in that the holes are conical with a taper upwards. 7. bituminous covering according to claims 1 - 3 and 5 - 6,
characterized in that structured inserts have upstanding knobs, corrugations or corrugations. 8. bituminous covering according to claims 1 - 2 and 7,
characterized in that the fragments of material which have arisen during the production of the holes by punching out, pressing out, etc. and are adhering to the edge of the holes are preserved. 9. Bituminous covering according to claim 8, characterized in that the perforations are provided on the outermost surface of the structures or on the sides of the structures or both on the outermost surface and on the sides of the structures in structured inserts. 10. Bituminous covering according to one of claims 1-9,
characterized in that the sealing layer is designed as a weld web with reinforcement by raw glass fleece or another carrier insert, such as glass mesh or polyester fleece etc. 11. Process for the formation of a bituminous covering for bridges with a superstructure made of concrete, in particular prestressed and reinforced concrete, the concrete surface being covered with a top layer of cast asphalt or asphalt concrete exposed to traffic and a protective layer, preferably also made of cast asphalt, and between the protective layer and the concrete surface , if necessary with the help of a primer of bituminous adhesive or a plastic adhesive, a sealing layer is spread out,
characterized in that the sealing layer consists of a bituminous material reinforced by a carrier insert, on the surface of which repels the concrete a metal or polymeric plastic layer is laid, which is perforated or perforated, w8: ei the resulting free surface between 1 and 25% of the total insert and the protective and cover layer is built up on this perforated or perforated insert. 12. The method according to claim 11, characterized in that the sealing layer is prefabricated in the factory from a bitumen welding sheet and perforated or perforated pad and is applied on site to the concrete surface pretreated with a bituminous adhesive or a plastic adhesive in the flame process and individual sheets of the sealing layer are overlapped with one another and welding.

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