EP4269692A1 - Superstructure for a traffic surface, method of manufacturing the superstructure - Google Patents

Abstract

Superstructure (100) for a traffic area, the superstructure (100) comprising a base layer (110) made of a mastic asphalt, and an intermediate layer (120) arranged on the base layer (110) made of an open-pored asphalt, the base layer (110) having an underside ( 123) of the intermediate layer (120) closes at least liquid-tight. The superstructure (100) comprises a cover layer (130) made of mastic asphalt arranged on the intermediate layer (120), the cover layer (130) closing an upper side (121) of the intermediate layer (120) at least in a liquid-tight manner. The superstructure (100) comprises at least one sealing wall (140) made of mastic asphalt arranged on at least one side surface (122a, 122b) of the intermediate layer (120), the at least one sealing wall (140) connecting the base layer (110) with the cover layer (130). connects and closes the at least one side surface (122a, 122b) at least in a liquid-tight manner, the mastic asphalt of the cover layer (130) containing graphite with a mass fraction of 1.25% to 5% of the mastic asphalt of the cover layer.

Description

Technical area

The invention relates to a superstructure for a traffic area, wherein the superstructure comprises a base layer made of a mastic asphalt, and an intermediate layer made of an open-pored asphalt arranged on the base layer, the base layer closing an underside of the intermediate layer at least in a liquid-tight manner. The invention further relates to a method for producing the superstructure.

State of the art

Asphalt is a temperature-dependent building material that achieves its optimal material properties within a temperature range from above 0 °C to around 40 °C. If the temperature deviates upwards from this interval, the material becomes increasingly viscous and deformations occur due to the traffic load, e.g. B: Ruts that weaken the overall superstructure and reduce usage time.

• Reduktion des Wohlbefindens aufgrund andauernd hoher Temperaturen (vor allem nachts durch Erschweren eines erholsamen Schlafs),
• negative gesundheitliche Konsequenzen über die andauernde Hitzebelastung des Herz-Kreislaufsystems,
• erhöhter Energiebedarf durch den gesteigerten Kühl- und Klimatisierungsbedarf.

In addition, asphalt surfaces in urban areas cause problems as a result of heating due to solar radiation, storage and subsequent release of thermal energy to the environment, whereby the asphalt surfaces increase the general temperature level and thus contribute to the urban heat island phenomenon. This results in the following problems:

• Reduction in well-being due to persistently high temperatures (especially at night by making restful sleep more difficult),
• negative health consequences due to the ongoing heat stress on the cardiovascular system,
• Increased energy requirements due to increased cooling and air conditioning requirements.

On the other hand, at low temperatures, problems arise due to cryogenic stresses within the asphalt superstructure and damage caused by freeze-thaw changes from water that has penetrated into the superstructure. Both lead to damage to the superstructure and a reduction in service life. This damage to the road structure, for example due to material discharge, leads to a reduction in comfort for road users and a reduction in traffic safety, even in non-slip seasons.

In addition to the material-related problems, frost also creates problems due to the asphalt surface becoming slippery and freezing over or snowing over. Slippery or snow-covered areas require winter maintenance to enable the areas to be used without danger. If road salt is used for winter road maintenance, problems also arise here due to the negative effects of road salt on groundwater, surrounding flora and fauna. The use of road salt can also lead to damage to vehicles and the surrounding buildings.

• die maximale Wärmeübertragungsfläche ist das Produkt der Länge des Rohrstrangs mit seiner Mantelfläche, was die maximale Wärmeübertragungsrate begrenzt,
• der Einbau von Rohren in den Oberbau und der Rückbau sind aufwändig und aufgrund des hohen Anteils an Handarbeit teuer,
• die Materialkosten des Rohrregisters führen zu hohen Gesamtkosten.

To reduce or avoid these problems, asphalt surfaces can be tempered. This temperature control takes place via the flow of fluid through the asphalt surface, which is usually carried in a pipe register. However, this results in the following disadvantages:

• the maximum heat transfer area is the product of the length of the pipe string by its lateral surface, which limits the maximum heat transfer rate,
• The installation of pipes in the superstructure and the dismantling are complex and expensive due to the high proportion of manual work,
• The material costs of the pipe register lead to high overall costs.

In order to overcome the disadvantages of the pipe register, the publications " Thermal and hydraulic analysis of multilayered asphalt pavements as active solar collectors" (P. Pascual-Muñoz, D. Castro-Fresno, P. Serrano-Bravo, A. Alonso-Estébanez, Applied Energy, Volume 111, 2013, Pages 324-332 , ISSN 0306-2619, https://doi.org/10.1016/j.apenergy.2013.05.013 ) and CN 101387097 A suggested using a porous intermediate layer instead of the pipe register to guide the fluid through the asphalt surface. This has the particular advantage of a higher heat transfer rate, since the contact area between asphalt and fluid corresponds to the inner surface of the pore volume.

However, the disadvantage of superstructures with a porous intermediate layer is that there is currently no known cost-effective method for reliably sealing the intermediate layer so that the fluid does not escape in an uncontrolled manner.

Technical task

The object of the invention is to create a temperature-controlled superstructure for a traffic area that can be manufactured, operated and dismantled cost-effectively, allows a high heat transfer rate and functions reliably over the long term without fluid loss.

Technical solution

The present invention provides a superstructure according to claim 1, which solves the technical problem. The object is also achieved by a method for producing the superstructure according to claim 10. Advantageous refinements are the subject of the dependent claims.

The invention relates to a superstructure for a traffic area. The traffic area can be, for example, a street, a cycle path, a sidewalk, a parking lot, a runway, a runway or a runway.

The superstructure includes a base layer made of mastic asphalt. The base layer, for example, has a thickness of 3 cm to 5 cm. A multi-layer design of the base layer consisting of several, for example two, layers each 3 cm to 4 cm thick is also possible.

Mastic asphalt is usually considered to be virtually vapor tight. However, it has been shown that in this application even the smallest cracks can lead to leaks. An increasing one Layer thickness reduces the likelihood that pores will extend through the entire base layer, or that cracks will communicate with each other and allow fluid to leak through them. A two-layer construction also reduces the likelihood of defects, cracks or pores in one layer extending through the entire base layer.

The use of mastic asphalt has the advantage that a good connection can be achieved with the porous intermediate layer and the other components of the structure due to the similar material properties. A good connection means fewer points of attack for fluid leakage.

Mastic asphalt also has low thermal conductivity, which keeps heat within the layer and does not dissipate into the ground. In addition to the sealing function, the mastic asphalt also has a thermal insulation function.

The superstructure comprises an intermediate layer made of open-pored asphalt arranged on the base layer, the base layer closing an underside of the intermediate layer in an at least liquid-tight, preferably also gas-tight manner.

This allows a heat transport fluid, for example water, to flow through the intermediate layer without escaping uncontrollably from the underside of the intermediate layer. The heat transport fluid can be used to temper the superstructure by either using colder heat transport fluid relative to the superstructure to cool the superstructure, or using warmer heat transport fluid relative to the superstructure to heat the superstructure. The heat absorbed by the heat transport fluid when cooling the superstructure can be converted into usable energy, for example with a heat engine. In addition, heat extracted from the superstructure in summer can be stored in order to use the heat to heat the superstructure in winter.

The intermediate layer can vary depending on the load and the boundary conditions such as temperature, solar radiation, Wind speed and surface properties can be made in different thicknesses. The layer thickness is, for example, between 4 cm and 8 cm. An intermediate layer with a layer thickness of 6 cm demonstrated good stability and conductivity in a long-term test.

A small layer thickness allows cost-effective production. The layer thickness of 6 cm is particularly suitable for a mix of water-permeable asphalt with a maximum grain diameter of 16 mm, whereby the mixture can have a composition similar to type PA 16 T WDA, for example.

The superstructure comprises a cover layer made of mastic asphalt arranged on the intermediate layer, the cover layer closing an upper side of the intermediate layer at least in a liquid-tight manner. The cover layer thus prevents the heat transport fluid from escaping uncontrollably from the intermediate layer through the top. The top layer can be produced particularly easily and cost-effectively from mastic asphalt and can be connected to the other components of the superstructure in a mechanically stable and liquid-tight manner.

The layer thickness of the top layer should be as small as possible in order not to impede the heat exchange between the surface of the top layer and the heat transport fluid in the intermediate layer. Depending on the material used, layer thicknesses of 2.5 cm to 3.5 cm are possible. A layer thickness of 3 cm is particularly easy to produce.

The layer thickness represents a compromise between high tightness, high mechanical resistance and high rigidity on the one hand and high thermal conductivity on the other.

For heat conduction, the layer thickness should be minimal in order to enable the highest possible heat transfer rate between the top of the cover layer and the porous intermediate layer or the heat transport fluid flowing through it.

The smaller the layer thickness, the higher the probability that individual defects will lead to leaks in the top layer. Although subsequent sealing is possible, it has a negative effect on heat transfer. A greater layer thickness also allows greater mechanical resistance and load transfer. In particular, as the thickness increases, the cover layer is better able to absorb part of the shear load that would otherwise have to be absorbed by the intermediate layer. Due to its nature, the porous intermediate layer is less suitable for absorbing the loads than the top layer.

The superstructure comprises at least one sealing wall made of mastic asphalt arranged on at least one side surface, preferably on two, three or four side surfaces, of the intermediate layer, the sealing wall connecting the base layer with the cover layer and closing the at least one side surface in an at least liquid-tight, preferably also gas-tight manner.

The sealing wall thus prevents the heat transport fluid from emerging from the intermediate layer in an uncontrolled manner on the side surface or surfaces. By using mastic asphalt, the sealing wall can be manufactured particularly easily and can be connected particularly stably and tightly to the base layer and the top layer, which also consist of mastic asphalt.

The sealing wall, for example, has a thickness between 20 cm and 30 cm perpendicular to the side surface. Tests have shown that this thickness is sufficient for a reliable seal. A smaller thickness of 12 cm is also possible, but is more susceptible to material defects that can lead to leaks that require rework. A thickness of the side sealing wall of more than 12 cm therefore has the advantage that it can be carried out with greater reliability without leaks.

A large thickness of the sealing wall leads to a large contact area of the sealing wall with the cover layer. A large contact surface makes this easier Sealing at the transition between the top layer and the side sealing wall, as the probability that individual errors will lead to a leak of heat transport fluid is significantly reduced.

A large thickness of the sealing wall also has the advantage that it has a thermally insulating effect and thus prevents heat from the intermediate layer or the heat transport fluid therein from being lost through the sealing wall.

Description of execution types

The superstructure preferably additionally comprises at least one connecting part arranged at least partially in the sealing wall for the at least liquid-conducting, preferably also gas-conducting, connection of a fluid line for a heat transport fluid to the intermediate layer, an outer side of the connecting part being connected to the sealing wall in an at least liquid-tight, preferably also gas-tight manner.

With the help of the connecting part, the fluid line can be connected to the intermediate layer particularly easily and without jeopardizing the tightness of the superstructure. The fluid line can, for example, comprise a pipe made of HDPE (High Density Polyethylene), which is characterized by good processability, weathering resistance, acid resistance and corrosion resistance.

The superstructure preferably comprises at least two connecting parts so that the heat transport fluid can be simultaneously introduced into the intermediate layer through one connecting part and discharged from the intermediate layer through another connecting part. The introductory connection part can be arranged higher, the same height or lower than the outgoing connection part on the intermediate layer.

The outside of the connecting part can be connected to the sealing wall in an at least liquid-tight manner, for example by a sealing ring or a plurality of sealing rings and/or a sealing compound, which can be arranged, for example, between the sealing rings. The sealant may be designed to prevent leaks due to movement of the Avoid sealing wall relative to the connecting part. For example, a sealing ring can be arranged in front of the sealing wall and a sealing ring can be arranged behind the sealing wall along the connecting part.

The connecting part can protrude into the intermediate layer or into the distributor pipe described below in order to promote the widest possible distribution in the intermediate layer of heat transport fluid introduced into the intermediate layer through the connecting part.

The superstructure preferably additionally comprises a distribution pipe arranged in the intermediate layer and connected to the connecting part in an at least liquid-conducting, preferably also gas-conducting manner, for distributing heat transport fluid introduced into the intermediate layer through the connecting part in the intermediate layer.

The distribution pipe can also be used as a collecting pipe for collecting the heat transport fluid for discharge from the intermediate layer through the connection part.

The distribution pipe promotes the large-area distribution of the heat transport fluid in the intermediate layer or the large-area collection of the heat transport fluid from the intermediate layer with a limited number of connecting parts and thus with a limited number of risk areas for leaks in the sealing wall.

The distribution pipe can, for example, comprise a profile rail that is closed on one side with a perforated plate. The profile rail and/or the perforated plate can be made of stainless steel or plastic, for example.

In order to avoid damage to the superstructure due to excessive pressure of the heat transport fluid, a fluid line through which the heat transport fluid is supplied to the superstructure, preferably a control fluid column, a pressure valve and/or a pressure reducer, for controlling and/or regulating the pressure of the heat transport fluid in the fluid line. The control fluid column is preferably designed as a riser pipe with an overflow for the heat transport fluid, the overflow the overflowing heat transport fluid preferably returns to a reservoir for the heat transport fluid. The maximum pressure in the fluid line is preferably adjustable via the height of the overflow above the fluid line in a range between 1 mbar and 100 mbar (1 cm to 100 cm of water column). However, a pressure of 100 mbar should only be used for short-term flushing of the superstructure. During operation of the superstructure, the pressure should be kept as low as possible without negatively affecting the temperature exchange between the heat transport fluid and the superstructure or leading to a discontinuous flow within the intermediate layer. Depending on the area of the intermediate layer and the flow rate of the heat transport fluid through the intermediate layer, the pressure during operation can be, for example, around 10 mbar.

The mastic asphalt of the base layer and/or the sealing wall preferably contains basalt, slag and/or other porous minerals as aggregate. The basalt, slag or porous mineral may form part of the aggregate of the mastic asphalt or all of the aggregate of the mastic asphalt. Basalt, slag and porous minerals are characterized by low thermal conductivity, so that heat losses from the intermediate layer are minimized through the base layer and/or the sealing wall.

The slag can include, for example, blast furnace slag, steelworks slag, slag from copper production and/or foundry cupola slag.

Since industrially produced aggregates based on slag are not as cost-effective as natural aggregates, they should preferably be used if no or insufficient natural aggregates with low thermal conductivity are available, or if the buildings adjacent to the superstructure or the soil in question are highly thermally conductive is.

The mastic asphalt of the base layer and/or the sealing wall preferably has a maximum grain diameter of 2 mm to 24 mm, preferably from 4 mm to 12 mm, particularly preferably from 5 mm to 11 mm. The mastic asphalt of the base layer has, for example, a maximum grain diameter of 8 mm or 11 mm. The mastic asphalt of the sealing wall has, for example, a maximum grain diameter of 5 mm.

The likelihood of cracks or continuous pores increases as the diameter of the largest grain of the mastic asphalt mixture increases, so the smallest possible largest grain is advantageous. On the other hand, the sealing wall and especially the base layer must be stable enough to absorb the load on the remaining superstructure plus the traffic running over it and to be able to transfer it to the layer below, for which the largest possible grain size is advantageous. The maximum grain diameters mentioned have proven to be a suitable compromise between a low tendency for defects and high stability for practical applications.

The open-pored asphalt of the intermediate layer preferably has a maximum grain diameter of 4 mm to 32 mm, preferably 8 mm to 24 mm, particularly preferably 16 mm.

As the diameter of the largest grain increases, the minimum necessary layer thickness increases and thus the mass of the superstructure and the costs for producing the superstructure also increase.

A large diameter of the largest grain has a positive effect on the pore structure. The number of connected pores, which have a positive influence on hydraulic conductivity, increases. Better hydraulic conductivity reduces the risk of build-up, which can damage the overall structure and ultimately lead to leaks. At the same time, with greater hydraulic conductivity, the amount of water circulated in the layer per unit of time can be increased, which can lead to better cooling and heating performance.

Mix of water-permeable asphalt with a maximum grain diameter of 16 mm, for example type PA 16 T A mixture similar to WDA, as an open-pored asphalt for the intermediate layer, results in the best compromise between conductivity for the heat transport fluid, mechanical resistance and layer thickness for practical applications. A version is also possible with water-permeable asphalt similar to type PA 8 D WDA (8 mm maximum grain diameter) or PA 22 T WDA (22 mm maximum grain diameter) if boundary conditions do not allow the use of a mixture similar to type WDA 16. A possible example is using the superstructure in an open parking garage. Due to the static construction of the building, the superstructure must not exceed a specified mass.

The open-pored asphalt of the intermediate layer preferably contains cellulose fibers with a mass fraction of 0.04% to 4%, preferably 0.1% to 0.5%, particularly preferably 0.4%, of the open-pored asphalt. The cellulose fibers prevent the binder from running off in order to allow the asphalt aggregate to adhere well to the binder.

The open-pored asphalt of the intermediate layer preferably contains carbon fibers with a mass fraction of 0.01% to 1%, preferably 0.05% to 0.2%, particularly preferably 0.1%, of the open-pored asphalt, the carbon fibers preferably being one Fiber length of 1 mm to 20 mm, particularly preferably from 3 mm to 10 mm, and / or have a tensile strength of 5 GPa to 6 GPa. An average fiber length of the carbon fibers is preferably 3 mm to 10 mm, particularly preferably 5 mm.

The carbon fibers are preferably recycled carbon fibers in order to minimize the costs and resource consumption of producing the superstructure.

In tests, an intermediate layer made of open-pored asphalt with a maximum grain diameter of 16 mm and a mass fraction of 0.1% carbon fibers and 0.4% cellulose fibers has proven to be a practical solution.

Modifying the open-pored asphalt with carbon fibers leads to reduced water sensitivity based on the hydrophobic properties of the carbon fibers. The carbon fibers also improve the cohesion of the porous intermediate layer, making it more resistant to shear loads and pore pressures.

Modifying the open-pored asphalt with a mass fraction of more than 0.1% carbon fibers leads to a slight improvement in the splitting tensile strength, but also increases water sensitivity and costs. Therefore, a mass fraction of 0.1% carbon fibers is particularly preferred.

A possible mechanism of action of the carbon fibers is that the carbon fibers mix with the cellulose fibers and distribute well when a small amount is added. This makes the carbon fibers water-repellent and the bitumen detaches from the aggregate to a lesser extent, so that damage is reduced or eliminated. Due to their stiffness, adding too much carbon fiber causes the rock framework to be pushed apart, so that the stability of the rock framework is reduced. However, once a certain amount is added, the carbon fibers can act like interlocking reinforcement. Mass fractions of carbon fibers between 0% and 5% in increments of 0.1 percentage points and with a total mass fraction of carbon fibers and cellulose fibers together of 0.5% were tested. The best variant across all studies was modified with a mass fraction of 0.1% carbon fibers.

The mastic asphalt of the cover layer preferably contains an aggregate suitable for road construction with high thermal conductivity, for example quartzite or greywacke, as aggregate, whereby the aggregate with high thermal conductivity can form part of the aggregate or the entire aggregate of the mastic asphalt of the cover layer. An aggregate with high thermal conductivity causes a high heat transfer rate between the Surface of the cover layer and the intermediate layer or the heat transport fluid therein.

The mastic asphalt of the cover layer preferably has a maximum grain diameter of 2 mm to 32 mm, preferably 4 mm to 16 mm, particularly preferably 8 mm.

Mastic asphalt with all of the maximum grain diameters mentioned, in particular 5 mm, 8 mm or 11 mm, can be used for the top layer. However, with smaller maximum grain diameters, more stiffening modifications must be made, or they should only be used on areas subject to less loading. For larger maximum grain diameters, the problem arises that the cover layer may be insufficiently tight. However, surface layers with a large maximum grain diameter can also be used for heavily trafficked traffic areas. A good compromise is an average maximum grain diameter of, for example, 8 mm with a modification of the mastic asphalt, for example with graphite.

The mastic asphalt of the cover layer can contain a high proportion of crushed sand in relation to the proportion of natural sand, for example a ratio of crushed sand proportion to natural sand proportion of 1.1: 1 or higher, in order to further improve the mechanical resilience.

The mastic asphalt of the top layer can contain waxes, for example fatty acid amides with a mass fraction of 0.1% to 0.9%, in particular 0.3%, to improve processability in order to produce a mastic asphalt designed with high rigidity (e.g. when modified with graphite and high crushed sand content).

The mastic asphalt of the cover layer preferably contains graphite with a mass fraction of 1% to 10%, preferably from 1.25% to 5%, particularly preferably 2.5%, of the mastic asphalt. Graphite improves the thermal conductivity of the top layer, enabling a high rate of heat transfer between the surface of the top layer and the intermediate layer or heat transport fluid therein.

In addition to improving thermal conductivity, the addition of graphite also has the effect that the graphite increases the rigidity and resistance to deformation of the top layer. This means that less stress is passed on to the porous intermediate layer. Since the top layer is better suited to absorbing loads and is easier to repair if damaged than the intermediate layer, this is an advantage. The addition of graphite also reduces the oxidation of the binder in the installed state of the surface layer and thus improves the aging properties of the asphalt binder, especially in relation to aging as a result of UV radiation.

The thermal conductivity of the top layer cannot be improved indefinitely by any amount of graphite by mass. Graphite has a high specific surface area and therefore requires a high level of binder. In order to obtain a stable surface layer, the mastic asphalt must contain more binder as the proportion of graphite increases. However, the bitumen used as a binder is a poor thermal conductor and therefore partially offsets the increase in thermal conductivity caused by graphite.

Above a maximum sensible mass fraction, a further increase in the mass fraction of graphite does not result in an increase in thermal conductivity and has a negative effect on the processability and structure of the mastic asphalt.

The mass fraction of graphite in the mastic asphalt of the top layer should therefore preferably be between 1.25% and 5.0%. A mass fraction of. 2.5% has proven particularly advantageous in tests. This significantly improves the thermal conductivity.

Conventional mastic asphalt can also be used for the top layer without modification to provide more thermal conductivity. However, this reduces the efficiency of the entire system.

The base layer preferably comprises a sealing layer arranged on an upper side and/or an underside of the base layer, wherein the sealing layer covers the upper side and/or the underside of the base layer at least liquid-tight, preferably also gas-tight, the sealing layer preferably comprising one or more mastic asphalt layers, a bitumen-impregnated fleece and/or a single- or multi-layer bitumen welding membrane. The mastic asphalt layers can, for example, have a thickness of 3 cm to 4 cm each.

The additional sealing layer provides additional protection against loss of heat transport fluid from the intermediate layer through the base layer. Unmodified mastic asphalt and bitumen weld membranes also have low thermal conductivity, which retains heat in the intermediate layer or heat transfer fluid within it and minimizes heat loss into the ground. In addition to the sealing function, the sealing layer also has a thermal insulation function.

The bitumen welding membrane also has the advantage that it can be produced with a lateral overhang over the base layer. Once the additional layers have been completed, this side overhang can be folded onto them to provide further lateral insulation and sealing.

The sealing layer is preferably arranged on the underside of the base layer in order not to impair a connection of the base layer with the intermediate layer and/or the sealing wall.

The base layer is preferably arranged on an asphalt base layer, for example with a bitumen mass content of 4% to 5%, preferably 4.2% to 4.8%, particularly preferably 4.5%.

The asphalt base layer preferably consists of a conventional asphalt day layer AC 22 T S in accordance with ZTV Asphalt-StB ("Additional Technical Contract Conditions and Guidelines for the Construction of Asphalt Pavements").

Compared to a conventional asphalt base layer, the asphalt base layer preferably contains a stronger, polymer-modified bitumen 25/55-55 A, 10/40-65 A or even 40/100-65 A in order to absorb any small tension that may occur without strong deflection can. The choice of binder depends on the strength achieved and the expected load on the entire superstructure and subsoil.

Due to the thicker structure compared to a conventional superstructure and the filling with heat transport fluid, the asphalt base layer must dissipate a greater load than with a conventional superstructure. The asphalt base course AC 22 T S can be used for all higher load classes according to ZTV Asphalt-StB, so that it can also permanently withstand the loads caused by the superstructure according to the invention.

An alternative to this would be the asphalt base layer AC 32 T S according to ZTV Asphalt-StB, which, however, has a larger pore volume and more connected pores due to the higher maximum grain diameter, which increases the risk of leaks.

The asphalt base course AC 22 T S is preferred because it can be used for all load classes. It also has the fewest pores compared to other asphalt base course designs in this load class, and the above-mentioned increased bitumen content further closes these pores.

The asphalt base layer is preferably constructed in such a way that, in addition to the base layer, it forms a further barrier for the heat transport fluid, which prevents the heat transport fluid from exiting the superstructure. In addition, the increased bitumen content of the asphalt base layer acts as a further thermal insulation layer to retain heat in the superstructure.

The asphalt base layer preferably contains at least a portion, in particular completely, of a less thermally conductive aggregate, such as. B. basalt, slag or another porous mineral.

The invention relates to a method for producing the superstructure according to the invention.

The process includes applying the base layer of the superstructure. The application is carried out, for example, as a mastic asphalt layer MA 8 S with road construction bitumen of grade 20/30 in accordance with ZTV Asphalt-StB with a thickness of 4 cm by hand or by machine. Before applying the base layer, the edge area can be placed using steel rails and aligned to the desired thickness of the base layer. The mastic asphalt of the base layer is preferably applied by hand or mechanically using a mastic asphalt plank at an installation temperature of 210 °C to 220 °C.

Before the base layer is applied, the asphalt base layer of the superstructure can be installed and compacted, in particular by machine. Here, the asphalt base layer, for example made of rolled asphalt, is installed mechanically with a paver and compacted with a suitable roller.

To improve the strength of the substrate, the substrate is preferably solidified before the asphalt base layer is applied, depending on its nature, in particular the moisture content, for example with a lime-cement mixture, in particular in a concentration between 20 kg/m ² to 40 kg/m ² . The solidification counteracts the formation of cracks in the base layer or in the sealing layer as a result of deflection of these layers due to an insufficiently solid substrate.

The solidification preferably results in a value of the compressive strength of the substrate of at least 4 N/mm ² being achieved.

The solidification is preferably carried out in such a way that no cracks arise in the substrate, which could penetrate into the base layer or into the sealing layer as reflection cracks.

An unbound base layer is preferably applied to the subsoil solidified in this way before the asphalt base layer is applied. For the elasticity moduli of the unbound base layer, the information given in the guidelines for the standardization of the superstructure of traffic areas (RStO) for load class 32 is preferably not fallen short of.

The method includes attaching the sealing wall to the base layer.

Before attaching the sealing wall made of mastic asphalt, a double-walled formwork made of wood is preferably made all around. When installing, for example, the mastic asphalt MA 5 S is applied in layers with road construction bitumen grade 20/30 according to ZTV Asphalt-StB at an installation temperature of 210 °C to 220 °C and tumbled by hand with a wooden grater in order to avoid cavities between the layers.

A distribution pipe can be attached to the base layer, which can be designed, for example, as a profile rail made of stainless steel with perforated stainless steel plate, as a profile rail made of plastic (e.g. thermoplastic) with perforated stainless steel plate or as a profile rail made of plastic with perforated plastic plate. After the base layer has been applied, but before it has cooled, iron is laid out, for example, at the intended position of the distribution pipe. Due to the weight of the iron, the base layer is lowered by a few millimeters, creating a recess into which the distributor pipe can be partially inserted. After the base layer has cooled, the irons are removed.

In the recess, the surface of the base layer can be removed by grinding or other methods for a better bond with the distribution pipe. The sides of the distribution pipe that will be in contact with mastic asphalt are preferably roughened. A primer is preferably applied to the contact surface of the base layer in the recess, as well as to the contact surface of the distributor pipe: a mastic asphalt primer for the mastic asphalt sealing layer and either a plastic or steel primer for the distributor pipe. In the next step, the distribution pipe is glued to the base layer, preferably via the primer using a liquid plastic.

The method includes introducing the intermediate layer of the superstructure onto the base layer, so that the at least one side surface of the intermediate layer is sealed by the sealing wall. The intermediate layer is created, for example, by hand or by machine using an asphalt paver at a temperature of the asphalt of the intermediate layer of 140 ° C to 175 ° C, preferably from 160 ° C to 170 ° C, and rolled with a roller statically and only with one pass over the surface.

If the subsurface has a strong slope, the compensation of which is not possible or sensible for technical or cost reasons, conductive materials and/or separating materials are preferably introduced into the intermediate layer, which conduct the heat transport fluid within the intermediate layer.

To introduce the conductive materials and/or separating materials, after installing the intermediate layer, a joint with a depth of, for example, 6 cm or the depth of the intermediate layer and/or a width of, for example, 10 mm to 15 mm is produced, preferably with a cutting cutter.

In a first embodiment, after the joint has been produced, the two end faces of the intermediate layer exposed by the separating cut are closed, for example with liquid plastic (e.g. polymethyl methacrylate) without a carrier insert, in order to avoid spreading into the intermediate layer. In the second step, a fast-reactive mortar, for example the fast-reactive mortar Repro 3K based on polymethyl methacrylate, is filled flush with the surface. After the filled mortar has hardened (depending on the addition of a catalyst and the air temperature), the top layer can be installed on top.

In a second embodiment, an asphalt mastic, for example an asphalt mastic 0/2, is introduced into the joint after the joint has been produced. After the asphalt mastic has cooled, the top layer can be installed. If necessary, it is also advantageous here in advance to close the end faces of the intermediate layer adjacent to the joint, for example with a bitumen hot coat, in order to prevent the asphalt mastic from spreading into the intermediate layer.

In a third embodiment, after the joint has been produced, a layer of a stable, elastic two-component sealant is placed on the base layer, For example, the two-component sealant Sika Tank PK-25ST based on polysulfide, for example with a width of 10 mm, is introduced into the joint. In a second step, for example, a Plexiglas pane with a width of, for example, 8 mm to 10 mm is used, which is preferably also glued in the upper part of the intermediate layer with a layer of a stable, elastic two-component sealant. After the two-component sealant has hardened, the top layer is installed.

In a fourth embodiment, after the joint has been produced, a foam strip (e.g. foam rubber) or an impregnated and pre-compressed sealing tape (e.g. a sealing tape used when installing windows) is installed in the joint. After the foam strip or sealing tape has expanded, the top layer can be installed.

In all four configurations, the deformation over the joint under the expected traffic load is preferably checked for suitability in the form of a track formation test or an equivalent road construction study before large-scale installation.

The method includes applying the top layer of the superstructure at least to the intermediate layer. The top layer of mastic asphalt is applied, for example, in the same way as the base layer of mastic asphalt is applied.

During transport to the construction site, the temperature of the mastic asphalt for the top layer is preferably kept at 200 °C in the digester vehicle in order to avoid embrittlement of the mastic asphalt. For example, half an hour before installation, the mastic asphalt is heated to the installation temperature of, for example, 225 °C. The elevated temperature is chosen to achieve better processability of the mastic asphalt if it contains graphite.

A spreading material to increase the roughness is preferably applied to the still hot surface of the top layer at an early stage and with a Roller statically pressed in. Unbound spreading material is preferably removed after the top layer has cooled.

The sealing wall is preferably attached to an upper side of the base layer. The cover layer is preferably applied to an upper side of the sealing wall. By attaching or applying it to the top of the base layer or the sealing wall, a particularly stable and tight connection of the sealing wall to the base layer or the cover layer is achieved.

The method preferably additionally includes applying and preferably pressing a bituminized chippings, preferably with a diameter of 0.1 mm to 0.6 mm, particularly preferably 0.3 mm, onto the top of the not yet cooled base layer before applying the Sealing wall on the top and/or on the top of the not yet cooled sealing wall before applying the cover layer to the top. The pressing is done, for example, with a roller.

The grit creates a rough surface with which the sealing wall or cover layer applied to it bonds particularly stably and tightly.

The top layer is preferably applied at a temperature of the mastic asphalt of the top layer of 220 ° C to 230 ° C, preferably 225 ° C. The temperatures mentioned lead to a particularly tight connection between the cover layer and the sealing wall. The top layer is preferably applied at a higher temperature than the base layer is applied and the sealing wall is attached, so that the mastic asphalt of the top layer can be processed well despite modification with graphite.

Applying the top layer preferably includes rolling the top layer with grit. The grit ensures that the surface of the surface layer is sufficiently rough for safe use of the traffic area. In addition, rolling will remove any existing ones Capillary pores that could lead to leaks are pushed out of the top layer.

The application of the base layer and/or the attachment of the sealing wall preferably takes place at a temperature of the mastic asphalt of the base layer and/or the sealing wall of 200 ° C to 230 ° C, preferably of 210 ° C to 220 ° C. The temperatures mentioned lead to a particularly tight connection between the base layer and the sealing wall.

The method preferably additionally includes creating, preferably drilling, an opening through the sealing wall and preferably introducing a connecting part into the opening, so that the connecting part is set up for at least liquid-conducting, preferably also gas-conducting, connection of a fluid line to the intermediate layer.

Drilling through the sealing wall is carried out, for example, using a masonry drill with an outside diameter of, for example, 0.5 inches to 1.5 inches.

For example, drilling is carried out with a 4-stage drill attachment in order to obtain a clean wall and not allow for a non-circular drill run, which could lead to an uneven hole, which in turn could make sealing difficult.

After drilling through the sealing wall, a cavity is preferably then drilled into the intermediate layer using a 4-stage drill.

If the intermediate layer contains a distribution pipe, access is preferably drilled into the distribution pipe through the opening in the sealing wall and preferably a cavity is drilled into the intermediate layer through the distribution pipe. Depending on the material of the distribution pipe, which can consist of a profile rail and a perforated plate, different drills can be used, for example an iron drill to drill through a distribution pipe, a profile rail or a perforated plate made of stainless steel, or a 4-stage drill to go through a Distributor pipe, a profile rail or a perforated plate made of plastic and drill into the porous intermediate layer.

The method preferably additionally comprises an at least liquid-tight, preferably also gas-tight, connection of an outside of the connecting part to the sealing wall.

The method preferably additionally includes an at least liquid-conducting, preferably also gas-conducting, connection of the fluid line to the connecting part. The opening through the sealing wall is preferably sucked out and/or the entire intermediate layer is preferably flushed, in particular in both directions, before the fluid line is connected to the connecting part in order to avoid contamination, deposits or blockages in the system of fluid line connecting part and intermediate layer. If necessary, the suctioning and/or rinsing can be carried out after the superstructure has been completed, for example in order to remove contaminants that have entered the opening and/or the intermediate layer as a result of repairs or conversion work on the superstructure.

Brief description of the drawings

• Figur 1 zeigt einen schematischen Querschnitt durch einen erfindungsgemäßen Oberbau.
• Figur 2 zeigt einen schematischen Querschnitt durch einen erfindungsgemäßen Oberbau und seine Versorgung mit dem Wärmetransportfluid.
• Figur 3 zeigt einen vergrößerten Ausschnitt aus Figur 2 im Bereich der Kontroll-Fluidsäule.
• Figur 4 zeigt den Ausschnitt aus Figur 3 mit einer alternativen Ausgestaltung der Versorgung des Oberbaus mit dem Wärmetransportfluid.

Further advantages, aims and properties of the invention are explained with reference to the following description and the accompanying drawings, in which objects according to the invention are shown as examples.

• Figure 1 shows a schematic cross section through a superstructure according to the invention.
• Figure 2 shows a schematic cross section through a superstructure according to the invention and its supply with the heat transport fluid.
• Figure 3 shows an enlarged section Figure 2 in the area of the control fluid column.
• Figure 4 shows the section Figure 3 with an alternative design for supplying the superstructure with the heat transport fluid.

Fig.1

Figure 1 shows a schematic cross section through a superstructure 100 according to the invention.

The superstructure 100 shown comprises a base layer 110, for example with a thickness of 3 cm to 5 cm, made of mastic asphalt, for example with a maximum grain diameter of 8 mm or 11 mm and with basalt as aggregate.

The superstructure 100 shown comprises an intermediate layer 120 arranged on the base layer 110, for example with a thickness of 6 cm, made of an open-pored asphalt, the base layer 110 closing an underside 123 of the intermediate layer 120 at least in a liquid-tight manner. The open-pored asphalt, for example, has a maximum grain diameter of 16 mm and contains a mass fraction of 0.1% carbon fibers and 0.4% cellulose fibers. For example, the carbon fibers have a fiber length of 3 mm to 10 mm with an average fiber length of 5 mm and a tensile strength of 5 GPa to 6 GPa.

The superstructure 100 shown comprises a cover layer 130 arranged on the intermediate layer 120, for example with a thickness of 3 cm, made of mastic asphalt, the cover layer 130 closing an upper side 121 of the intermediate layer 120 at least in a liquid-tight manner. The mastic asphalt of the cover layer 130 contains, for example, quartzite as aggregate and a mass fraction of 2.5% graphite.

The superstructure 100 shown comprises at least one sealing wall 140 arranged on at least one side surface 122a, 122b, in the drawing on a left side surface 122a and on a right side surface 122b, of the intermediate layer 120, for example with a width of 20 cm to 30 cm, made of one Mastic asphalt, wherein the sealing wall 140 connects the base layer 110 with the cover layer 130 and closes the at least one side surface 122 at least in a liquid-tight manner. The mastic asphalt of the sealing wall 140 contains, for example, basalt with a maximum grain diameter of 5 mm as aggregate.

The superstructure 100 shown comprises at least one connecting part 145 arranged at least partially in the at least one sealing wall 140 for at least liquid-conducting connection of a fluid line 150 for a heat transport fluid to the intermediate layer 120, an outer side 146 of the connecting part 145 being connected to the at least one sealing wall 140 in an at least liquid-tight manner .

In Figure 1 Two connection parts 145 are shown, one of which can serve, for example, as an inlet for the heat transport fluid into the intermediate layer and the other as an outlet for the heat transport fluid from the intermediate layer.

The base layer 110 shown comprises a sealing layer 115 arranged on an underside 113 of the base layer 110, the sealing layer 115 at least sealing the underside 113 of the base layer 110 in a liquid-tight manner, the sealing layer 115 comprising, for example, a bitumen welding membrane.

The base layer 110 shown is arranged on an asphalt base layer 160, for example with a bitumen mass content of 4.5%. The asphalt base layer 160 can be a conventional asphalt base layer AC 22 T S according to ZTV Asphalt-StB. The asphalt base layer 160 contains, for example, basalt as aggregate.

Fig.2

Figure 2 shows a schematic cross section through a superstructure 100 according to the invention and its supply with the heat transport fluid.

The superstructure 100 shown can, for example, be as in Figure 1 shown, although for the sake of clarity not all features of the superstructure 100 are shown and labeled.

Some dimensions are in Figure 2 for example, measured in meters.

The intermediate layer 120 of the superstructure 100 is connected to the connecting parts 145 of the superstructure by fluid lines 150 supplied with the heat transport fluid (represented by arrows), for example water. The connecting part 145, through which the heat transport fluid is introduced into the intermediate layer 120 (in Figure 2 right), for example as in Figure 2 shown be arranged higher than the connecting part 145, through which the heat transport fluid is removed from the intermediate layer 120 (in Figure 2 Left).

The heat transport fluid is pumped, for example, with a pump 180 from a reservoir 170 through a fluid line 150 into the intermediate layer 130 and returned through a further fluid line 150 from the intermediate layer 130 into the reservoir 170.

The fluid line 150 leading to the intermediate layer 130 can be a flow measuring device and/or a pressure gauge 152 for measuring the flow of the heat transport fluid into the intermediate layer 130 and/or for measuring the pressure of the heat transport fluid in the fluid line 150 and/or a valve 151, in particular a flow control valve Have regulation of the flow.

The fluid line 150 leading to the intermediate layer 130 may have a control fluid column 190 for controlling the pressure in the fluid line 150 and/or a pressure control valve 202 for adjusting the pressure in the fluid line 150.

The control fluid column 190 preferably includes an overflow 192 through which the heat transport fluid flows into the reservoir 170 when a maximum pressure is exceeded. To set the maximum pressure, the overflow 192 is preferably adjustable in height above the fluid line 150 (indicated by dashed lines).

The pressure control valve 202 preferably includes a relief drain 201, via which excess heat transport fluid is returned to the reservoir 170.

Fig.3

Figure 3 shows an enlarged section Figure 2 in the area of the control fluid column 190.

The control fluid column 190 may include a length-adjustable riser 191 for the heat transport fluid from the fluid line 150 to adjust the height of the overflow 192 above the fluid line 150.

Fig.4

Figure 4 shows the section Figure 3 with an alternative embodiment of the supply of the superstructure 100 with the heat transport fluid. In this embodiment, instead of the pressure control valve 202 with relief drain 201, a pressure reducer 200 is provided for adjusting the pressure in the fluid line 150. <b>List of reference symbols</b> 100 superstructure 150 Fluid line 110 Base layer 151 Valve 113 Bottom of the base layer 152 Flow meter and/or pressure gauge 115 sealing layer 160 Asphalt base course 120 Interlayer 170 reservoir 121 Top of the intermediate layer 180 pump 122a, 122b Side surface of the intermediate layer 190 Control fluid column 123 Bottom of the intermediate layer 191 Riser pipe 130 top layer 192 overflow 140 sealing wall 200 Pressure reducer 141 Top of the sealing wall 201 Relief process 145 Connection part 202 Pressure control valve 146 Outside of the connecting part

Claims (15)

Superstructure (100) for a traffic area, comprising the superstructure (100). a. a base layer (110) made of mastic asphalt, and b. an intermediate layer (120) arranged on the base layer (110) made of an open-pored asphalt, the base layer (110) closing an underside (123) of the intermediate layer (120) at least in a liquid-tight manner, and c. a cover layer (130) made of mastic asphalt arranged on the intermediate layer (120), the cover layer (130) closing an upper side (121) of the intermediate layer (120) at least in a liquid-tight manner, and d. at least one sealing wall (140) made of mastic asphalt arranged on at least one side surface (122a, 122b) of the intermediate layer (120), wherein the at least one sealing wall (140) connects the base layer (110) to the cover layer (130) and the at least one side surface (122a, 122b) at least sealed in a liquid-tight manner,
characterized in that e. the mastic asphalt of the top layer (130) contains graphite with a mass fraction of 1.25% to 5% of the mastic asphalt of the top layer (130). Superstructure (100) according to claim 1,
characterized in that
the superstructure (100) additionally comprises at least one connecting part (145) arranged at least partially in the at least one sealing wall (140) for at least liquid-conducting connection of a fluid line (150) for a heat transport fluid to the intermediate layer (120), wherein an outer side (146) of the Connecting part (145) is connected at least in a liquid-tight manner to the at least one sealing wall (140). Superstructure (100) according to claim 2,
characterized in that
the superstructure (100) is additionally arranged in the intermediate layer (120) and at least conducts liquid to the connecting part (145) connected distribution pipe for distributing heat transport fluid introduced into the intermediate layer (120) through the connecting part (145) in the intermediate layer (120). Superstructure (100) according to one of claims 1 to 3,
characterized in that
the mastic asphalt of the base layer (110) and/or the at least one sealing wall (140) a. Contains basalt and/or slag as aggregate and/or b. has a maximum grain diameter of 2 mm to 24 mm, preferably from 4 mm to 12 mm, particularly preferably from 5 mm to 11 mm. Superstructure (100) according to one of claims 1 to 4,
characterized in that
the open-pored asphalt of the intermediate layer (120) a. has a maximum grain diameter of 4 mm to 32 mm, preferably 8 mm to 24 mm, particularly preferably 16 mm, and/or b. Cellulose fibers with a mass fraction of 0.04% to 4%, preferably 0.1% to 0.5%, particularly preferably 0.4%, of the open-pored asphalt. Superstructure (100) according to one of claims 1 to 5,
characterized in that
the open-pored asphalt of the intermediate layer (120) contains carbon fibers with a mass fraction of 0.01% to 1%, preferably 0.05% to 0.2%, particularly preferably 0.1%, of the open-pored asphalt, the carbon fibers preferably have a fiber length of 1 mm to 20 mm, particularly preferably 3 mm to 10 mm, and/or a tensile strength of 5 GPa to 6 GPa. Superstructure (100) according to one of claims 1 to 6,
characterized in that
the mastic asphalt of the top layer (130) a. contains an aggregate with high thermal conductivity, preferably quartzite or greywacke, as aggregate, b. has a maximum grain diameter of 2 mm to 32 mm, preferably 4 mm to 16 mm, particularly preferably 8 mm, and/or c. Contains graphite with a mass fraction of 2.5% of the mastic asphalt of the top layer (130). Superstructure (100) according to one of claims 1 to 7,
characterized in that
the base layer (110) comprises a sealing layer (115) arranged on an upper side and/or an underside (113) of the base layer (110), the sealing layer (115) covering the upper side and/or the underside (113) of the base layer (110 ) closes at least in a liquid-tight manner, the sealing layer (115) preferably comprising one or more mastic asphalt layers, a bitumen-soaked fleece and/or a bitumen welding membrane. Superstructure (100) according to one of claims 1 to 8,
characterized in that
the base layer (110) is arranged on an asphalt base layer (160) with a bitumen mass content of 4% to 5%, preferably 4.2% to 4.8%, particularly preferably 4.5%. Method for producing the superstructure (100) according to one of claims 1 to 9, the method comprising the following steps: a. Applying the base layer (110) of the superstructure (100), b. Attaching the at least one sealing wall (140) to the base layer (110), c. Introducing the intermediate layer (120) of the superstructure (100) onto the base layer (110), so that the at least one side surface (122a, 122b) of the intermediate layer (120) is sealed by the at least one sealing wall (140), and d. Applying the cover layer (130) of the superstructure (100) at least to the intermediate layer (120). Method according to claim 10,
characterized in that a. the at least one sealing wall (140) is attached to an upper side of the base layer (110) and/or b. the cover layer (130) is applied to an upper side of the at least one sealing wall (140). Method according to claim 10 or 11,
characterized in that
the method additionally comprises applying and preferably pressing on a bituminized chippings, preferably with a diameter of 0.1 mm to 0.6 mm, particularly preferably of 0.3 mm a. on the top side (111) of the not yet cooled base layer (110) before attaching the at least one sealing wall (140) to the top side (111) and/or b. on the top side (141) of the not yet cooled at least one sealing wall (140) before applying the cover layer (130) to the top side (141). Method according to one of claims 10 to 12,
characterized in that
the application of the top layer (130) a. at a temperature of the mastic asphalt of the cover layer (130) of 220 ° C to 230 ° C, preferably of 225 ° C, and / or b. includes rolling off the top layer with chippings. Method according to one of claims 10 to 13,
characterized in that
the application of the base layer (110) and/or the attachment of the at least one sealing wall (140) at a temperature of the mastic asphalt of the base layer (110) and/or the at least one sealing wall (140) of 200 ° C to 230 ° C, preferably from 210 °C to 220 °C. Method according to one of claims 10 to 14,
characterized in that
the procedure additionally includes the following steps: a. Creating, preferably drilling, an opening through the at least one sealing wall (140), b. Introducing a connecting part (145) into the opening, so that the connecting part (145) is set up for at least liquid-conducting connection of a fluid line (150) to the intermediate layer (120), c. at least liquid-tight connection of an outer side (146) of the connecting part (145) to the at least one sealing wall (140) and d. at least liquid-conducting connection of the fluid line (150) to the connecting part (145).

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