Method and system for preparing a road for renovation

Abstract

The invention relates to a method for preparing a road (1) for renovation, having the following steps: - measuring the surface area (4) of the road (1) using an optical measuring method, in particular using a laser scanner (8); - ascertaining the asphalt paving layer thickness (5) using a ground penetrating radar (9); - generating a 3D model of the road (1), said 3D model containing the previously measured surface area (4) and the ascertained asphalt paving layer thickness (5); - comparing the asphalt paving layer thickness (5) in the 3D model with a defined maximum value in order to determine excess asphalt paving sections (10) of the asphalt paving (2) in the 3D model; - cutting off the excess asphalt paving sections (10); - transporting away the cut-off asphalt paving sections (10a); and - through-cutting the remaining asphalt paving (20).

Description

[0001] Method and system for preparing a road for rehabilitation

[0002] The invention relates to a method for preparing a road for rehabilitation, a device for creating a 3D model of a road, and a system for preparing a road for rehabilitation.

[0003] In Europe in particular, there are high demands on roads such as expressways, motorways and even smaller side roads with regard to their structure and quality. The structure of roads can be divided into subgrade, substructure and superstructure. The subgrade is formed by the soil and can, if necessary, be consolidated using geogrids, geocells or fleece. The subgrade is typically followed by the subgrade, which is artificially created. The subgrade can serve to level out unevenness in the ground and improve the load-bearing capacity of the ground. The subgrade concludes with what is known as the subgrade. The subgrade or the subgrade of the subgrade is followed by the superstructure of the road. The superstructure can have several base layers, with a distinction being made between bound and unbound base layers.Bound base courses are stabilized by mixing a base material (e.g., aggregate) with a binding agent and then compacting it. Road base courses, in particular, must withstand changing climatic conditions (heat, frost, snow, rain, etc.) as well as the heavy mechanical stresses caused by road traffic. Binding agents that can be used include cement, base course binders, or bitumen emulsion with cement. An asphalt surface often forms the upper surface of the road, upon which traffic ultimately travels.

[0004] Due to the heavy use that roads are subject to and the high demands placed on roads in terms of traffic safety, it is necessary to rehabilitate roads at regular intervals and / or when necessary. In most cases, road rehabilitation only affects the road surface, i.e. one or more base layers. This typically involves milling away the affected base layers and replacing them either completely or partially with new material. A portion of the milled-away material can be reused. For example, a portion of the milled-through base layer can be mixed with lime or cement and used again as the base layer for the rehabilitated road. A (further) bound base layer can be applied over the reprocessed base layer. Optionally, an asphalt surface can be applied as a surface layer.Construction requirements for roads in Austria with regard to manufacturing processes, machines, building materials, layer thicknesses and testing methods are laid down, for example, in the "Guidelines and Regulations for Road Construction" (RVS), in particular in RVS 08.17.01 (title: "Base courses stabilized with binder") as well as in RVS 03.08.63 (title: "Superstructure design") and RVS 08.16.01 (title: "Requirements for asphalt layers").

[0005] Such rehabilitation measures can be costly, time-consuming, and also result in significant CO2 emissions. Furthermore, during rehabilitation, there is typically increased traffic congestion on surrounding (alternative) roads, resulting in traffic jams and the associated waiting times and detours, which further contribute to the overall rehabilitation costs. It is therefore necessary to carry out rehabilitation as quickly as possible and using as few resources as possible (such as labor hours, machine hours, and materials), without compromising the quality of the rehabilitated road and, consequently, road safety. One of the key factors for the efficient rehabilitation of a road is appropriate and accurate planning.

[0006] For example, AT 17 051 Ul describes a method for determining maintenance measures for a road. In several sections of the road, the thickness of the unbound base layer and the bound base layer is measured, and the road's surface structure is optically recorded. A load-bearing capacity value and a surface structure value are assigned to each section. From these values, a maintenance category (maintenance, repair, reinforcement, and new construction) is determined. A ground-penetrating radar (GPR) is used to measure the layer thickness.

[0007] CN 107 761 529 B shows a device for detecting and repairing road surface damage. This device comprises a camera and a geo-radar connected to a processor. The processor creates a 3D model of the road from the camera images and the geo-radar data. The 3D model shows damage (such as cracks) in the road, which can then be repaired.

[0008] CN 107 544 095 B shows the integration of ground-penetrating radar measurement data into a 3D point cloud of the road surface captured by a laser scanner. The ground-penetrating radar measurements are synchronized with GPS data. The ground-penetrating radar / GPS data and the laser scanner data are then linked in a common coordinate system.

[0009] Furthermore, it is generally known from the state of the art that core samples can be taken along a road undergoing rehabilitation to assess the condition of the road and the subsoil. Maintenance measures can be derived from the data obtained from the core samples. However, core sampling is not non-destructive and involves a relatively high level of effort, both in terms of sampling and analysis.

[0010] For example, to improve material consumption, at least a portion of the asphalt surface of the road to be rehabilitated is typically milled and reclaimed to serve as a base course for the rehabilitated road. For this purpose, a maximum thickness of the asphalt surface that may be reclaimed may be specified.

[0011] For example, US 2001 268 503 A1 discloses a method for continuously adjusting the height of a trench cutter. The trench cutter is equipped with a geo-radar, a laser sensor, and a GPS sensor. The height of the trench cutter can be adjusted to maintain a constant distance to an underground boundary surface.

[0012] DE 10 2014 015 661 A1 discloses a milling machine control system based on soil characteristics. A milling machine is provided with a soil characteristic sensor for determining soil characteristics. The milling machine is controlled according to the measured soil characteristics.

[0013] A disadvantage of the current state of the art is that road rehabilitation, in particular, continues to require a relatively high expenditure of labor, machine hours, and materials. In particular, a significantly larger amount of material is sometimes removed and replaced than necessary, and / or a disproportionately high number of machine hours, for example, from a milling machine, are used.

[0014] It is therefore an object of the invention to at least mitigate or completely eliminate the disadvantages of the prior art. In particular, it is an object of the invention to provide a method for preparing a road for rehabilitation, a device for creating a 3D model of a road, and a system for preparing a road for rehabilitation that reduces the expenditure of labor hours, machine hours, and material compared to currently known methods and devices.

[0015] The task is solved by a procedure for preparing a road for rehabilitation with the following steps:

[0016] - Measuring a road surface by means of an optical measuring method, in particular by means of a laser scanner;

[0017] - Determining the thickness of an asphalt surface using a geo-radar;

[0018] - Creating a 3D model of the road showing the previously measured surface and the determined asphalt surface layer thickness;

[0019] - Comparing the asphalt surface layer thickness in the 3D model with a predefined maximum value in order to determine excess asphalt surface portions of the asphalt surface in the 3D model;

[0020] - Milling off the excess asphalt surface;

[0021] - Removal of the milled asphalt surface parts; and

[0022] - Milling through a remaining asphalt surface.

[0023] The problem is also solved by a device for creating a 3D model of a road comprising:

[0024] - having a measuring vehicle

[0025] - an optical measuring device, in particular a laser scanner, for measuring a surface of the road; and

[0026] - a geo-radar to determine the thickness of the asphalt surface layer of the road;

[0027] - a data processing device which is designed to create a 3D model of the road comprising the previously measured surface and the determined asphalt surface layer thickness, wherein the data processing device is further designed to compare the asphalt surface layer thickness in the 3D model with a predefined maximum value in order to determine excess asphalt surface portions of the asphalt surface in the 3D model.

[0028] Furthermore, the object is achieved by a system for preparing a road for rehabilitation, comprising the device according to the invention for creating a 3D model of the road, with an asphalt milling machine, wherein the data processing device is set up to determine at least a first area and at least a second area of ​​the road in the 3D model, wherein the at least one first area in the 3D model has no excess asphalt surface portions, wherein the at least one second area has excess asphalt surface portions, wherein the data processing device is further set up to create a milling plan for milling off the excess asphalt surface portions on the basis of the at least one second area, wherein the asphalt milling machine is set up to mill off the excess asphalt surface portions in accordance with the milling plan.The road (to be rehabilitated) may, for example, comprise or consist of a section of one or more lanes of a motorway or expressway. The road may, for example, have a width ranging from 2 meters to 50 meters and may, for example, be at least 50 meters, optionally at least 1000 meters, long. The road may, as is known from conventional roads, have curves and / or an incline. The road may, for example, have a subgrade, a substructure and a superstructure.

[0029] The road, in particular the superstructure of the road, has an asphalt surface which forms a wearing course of the road. The asphalt surface can comprise bitumen and aggregates. A concrete surface can optionally be present above the asphalt surface, which is abraded and removed, for example, before the method according to the invention is used. The asphalt surface can optionally comprise concrete, for example the asphalt surface can comprise asphalt concrete. The asphalt surface can comprise asphalt and optionally a binder such as cement. The road has a lateral extent. The asphalt surface has an asphalt surface layer thickness. The asphalt surface layer thickness is a layer thickness of the road in the vertical direction. In the case of a road inclined relative to the vertical, the layer thickness is to be understood in the correspondingly inclined direction.

[0030] The asphalt surface layer thickness can vary along the road, i.e., it can have different values ​​at different points along the road. For example, the asphalt surface layer thickness of the road to be rehabilitated can be between 1 centimeter and 100 centimeters, in particular between 2 centimeters and 50 centimeters, and optionally between 6 centimeters and 30 centimeters.

[0031] A road surface can be formed by the asphalt surface of the road. The road surface can, for example, be a two-dimensional area. The asphalt surface of the road (to be rehabilitated) can, for example, exhibit damage such as cracks or holes that are to be repaired during rehabilitation. Such damage can, for example, be recorded on the road surface. The road can, for example, exhibit ruts caused by road traffic.

[0032] In one step of the process for preparing a road for rehabilitation, the surface of the road is measured using an optical measuring method. For this purpose, an optical measuring device such as a laser scanner can be provided and used. The optical measuring device can be arranged on or in a measuring vehicle, for example. The measuring vehicle can be a car, a truck or a construction vehicle. Alternatively, the measuring vehicle can also be a drone. The measuring vehicle can, for example, drive over the road to measure the surface of the road using the optical measuring device. The measuring vehicle can, for example, take part in road traffic, so that the road does not have to be closed while the measuring vehicle is surveying and traffic is not significantly disrupted.The measuring vehicle can, for example, use a positioning system such as a global navigation satellite system (GNSS, e.g. GPS) to record a position of the measuring vehicle while it is measuring the road surface. This means that the measured surface, or individual measured points on the surface, can be linked to position data. For example, the position of individual damage to the road can be determined. To measure the road surface, for example, reference points can be recorded and their position measured precisely. The measured surface can, for example, show ruts in the road. The optical measuring device can, for example, have a total station, by means of which the road surface can be measured.

[0033] In addition, the asphalt surface layer thickness of the road is determined using a geo-radar. The geo-radar can be installed (as well as the optical measuring device) on or in the

[0034] measuring vehicle can be arranged. The asphalt pavement layer thickness can, for example, be determined at the same time as the surface is being measured. This makes it particularly easy to link the determined data on the surface and asphalt pavement layer thickness and, optionally, position data, since the relative positions of individual data points have a known and relatively simple relationship. A geo-radar (also known as "ground penetrating radar" or "ground penetrating radar" (GPR)) allows the non-destructive measurement of layer thicknesses of a subsurface (such as the asphalt surface of a road) using high-frequency electromagnetic waves. These waves are scattered and / or reflected, particularly at boundary layers. Part of the reflected signal is in turn recorded by the geo-radar.The (vertical) resolution of the geo-radar with respect to the asphalt pavement thickness can, for example, be between 0.5 centimeters and 2 centimeters. The geo-radar can, for example, record measurement points with a frequency of up to 1000 Hz (i.e., 1000 measurement points per second).

[0035] The asphalt surface layer thickness can be determined in close-meshed fashion using geo-radar. The asphalt surface layer thickness can, for example, be determined essentially continuously. The lateral distance between adjacent measuring points of the asphalt surface layer thickness can, for example, be a maximum of 1 m, in particular a maximum of 40 cm, for example a maximum of 20 cm. In particular, compared to determining the asphalt surface layer thickness of the road by taking drill cores, a significantly closer-meshed survey is possible using geo-radar. The geo-radar can have a GNSS antenna so that it can be located using GPS or Galileo, for example. The GNSS antenna of the geo-radar can be provided in addition to or instead of the location system of the measuring vehicle.

[0036] A 3D model of the road is then created, including the previously measured surface and the determined asphalt surface layer thickness. The measured surface and the determined asphalt surface layer thickness are combined with the correct position and height. Position data, recorded using GPS, for example, can optionally be used for this purpose. The 3D model of the road therefore depicts at least the surface of the road and the asphalt surface. From the 3D model of the road, for example, a length, a width and / or a total area of ​​the road can be determined. The 3D model can be displayed in a component coordinate system.

[0037] In a further step, the asphalt pavement layer thickness in the 3D model is compared with a predefined maximum value in order to determine and, in particular, to locate excess asphalt pavement portions in the 3D model. The predefined maximum value can, for example, be specified by a regulation or standard or can be derived from it. For example, it is known from RVS 08.17.01 that if the asphalt content (Ra) is a maximum of 50% (in relation to the base layer of roads after their rehabilitation), test specimens for the base layer must be produced using the Proctor method (see section 8.1.10 “Producing test specimens”). If the RA content is over 50%, test specimens must be produced using cyclic static compaction. In Austria, it is common practice to provide for less than 50% asphalt content (Ra) in the base layer of the rehabilitated road.This avoids the comparatively more costly test method based on cyclic static compaction. Furthermore, RA material requires a higher amount of binder. For quantities higher than 33 kg / m, 2In addition, two work steps (instead of just one) are typically required to mix the binder with the milled asphalt, as sufficient mixing cannot be guaranteed with just one work step. For this reason, an RA proportion of less than 50% is typically used. A typical thickness of a base course (after road rehabilitation) is, for example, 30 cm. In order to achieve an RA proportion that does not exceed 50% (but is still close to 50%), even taking into account any tolerances or uncertainties, a maximum asphalt surface layer thickness of 14 centimeters (= 30 cm * 0.5 - 1 cm) of the road to be rehabilitated is typically reprocessed and used as the starting material for the base course for the rehabilitated road. In particular with regard to the rehabilitation of roads in Austria, the predefined maximum value can be, for example, 14 centimeters.For example, at airports or locations with very high traffic volumes, a thicker base layer may be required. For example, the base layer thickness may be 50 cm. Typically, a maximum asphalt surface layer thickness of 24 centimeters (= 50 cm * 0.5 - 1 cm) is resurfaced on the road to be rehabilitated. The predefined maximum value in this case may be 24 centimeters, for example.

[0038] Excess asphalt pavement is present at positions or in sections where the asphalt pavement has a thickness exceeding the predefined limit. Excess asphalt pavement is that which exceeds the predefined maximum value. For example, the predefined maximum value may be 14 centimeters. For example, the asphalt pavement in one section may have a thickness of 20 centimeters. In this case, the top 6 centimeters (= 20 centimeters minus 14 centimeters) of the relevant section of the asphalt pavement are the excess asphalt pavement. The thickness of the excess asphalt pavement is generally location-dependent.

[0039] A data processing device is provided for creating the 3D model of the road comprising the previously measured surface and the determined asphalt surface layer thickness. The data processing device is further configured to compare the asphalt surface layer thickness in the 3D model with a predefined maximum value in order to determine the excess asphalt surface portion of the asphalt surface in the 3D model. The data processing device can be a computer, for example. The data processing device can have a computer-readable storage medium for storing the predefined maximum value, the asphalt surface layer thickness, the measured surface and the 3D model. The data processing device is configured to receive data from the optical measuring device and the geo-radar.For example, the data processing device can be connected to the measuring vehicle in order to receive data from the optical measuring device and the geo-radar with the aid of the measuring vehicle. For this purpose, the measuring vehicle can be configured to receive data from the optical measuring device and the geo-radar and forward it to the data processing device. Alternatively, the data processing device can be part of the measuring vehicle, for example.

[0040] In a further step, the previously determined excess asphalt surface portions are milled off. For example, an asphalt milling machine can be used for this purpose.

[0041] In a next step, the milled-off (excess) asphalt surface portions are removed. After the excess material, i.e. the milled-off excess asphalt surface portions, has been removed, the remaining asphalt surface is milled through. In this step, an unbound base course can also be milled through at the same time if this is necessary or desirable during the rehabilitation. The remaining asphalt surface can correspond to the asphalt surface of the road to be rehabilitated without the excess asphalt surface portions. If an asphalt milling machine is used to mill off the excess asphalt surface portions, it may be necessary to mill off somewhat more material than just the excess asphalt surface portions, for example due to the width of the asphalt milling machine. The remaining asphalt surface ultimately has a layer thickness that does not exceed the predefined maximum value.

[0042] The method according to the invention thus enables efficient planning and preparation of a road for rehabilitation. By means of the 3D model, which on the one hand has optical measurement data on the surface and location-dependent information on the asphalt surface layer thickness, it is possible to reduce the use of resources such as machine hours (particularly asphalt milling machines), working hours and also construction materials. This is achieved in particular by comparing the asphalt surface layer thickness in the 3D model with the predefined maximum value (i.e. determining the excess asphalt surface portions), milling off the excess asphalt surface portions, removing the milled-off asphalt surface portions and milling through the remaining asphalt surface.

[0043] Optionally, the following step can be provided before milling off the excess asphalt surface portions:

[0044] - Determining at least a first region and at least a second region of the road in the 3D model, wherein the at least one first region in the 3D model has no excess asphalt surface portions, wherein the at least one second region has excess asphalt surface portions. The road can be divided into regions with and regions without excess asphalt surface portions. The road can have at least a first region without excess asphalt surface portions and at least one second region with excess asphalt surface portions. In addition to sections of the road with excess asphalt surface portions, the at least one second region can also have sections of the road without excess asphalt surface portions. In contrast, the at least one first region can have no excess asphalt surface portions.This distinction allows at least a first area to be identified that is not affected by the steps of milling off the excess asphalt surface and removing the milled asphalt surface. These steps are therefore only necessary in at least one second area. However, milling through the remaining asphalt surface is planned in both at least one first area and at least one second area.

[0045] Optionally, the following additional step can be provided before milling off the excess asphalt surface:

[0046] - Creating a milling plan for milling off the excess asphalt surface portions based on the at least one second area; wherein the milling of the excess asphalt surface portions is carried out in accordance with the created milling plan. The milling plan can specify a timing of the milling. For example, an asphalt milling machine can be controlled to mill off the excess asphalt surface portions in accordance with the milling plan. The milling plan can also improve the planning of the removal of the (milled off) excess asphalt surface portions. The milling plan can, for example, only take into account the at least one second area, since the at least one first area does not have any excess asphalt surface portions anyway. The milling plan is created on the basis of the at least one area.The milling plan can, in particular, reduce the number of machine hours required by the asphalt milling machine, since the asphalt milling machine does not necessarily have to work on at least the first section while milling off the excess asphalt surface. Asphalt milling machines are typically large, heavy, and sluggish machines that also have high energy requirements. Reducing the machine hours required by asphalt milling machines or similar equipment can therefore significantly reduce the overall duration and resource consumption of road rehabilitation.

[0047] The system for preparing a road for rehabilitation comprises the device according to the invention for creating a 3D model of the road and an asphalt milling machine. The data processing device is set up to determine the at least one first region and the at least one second region of the road in the 3D model. The at least one first region in the 3D model has no excess asphalt surface portions, wherein the at least one second region has excess asphalt surface portions. The data processing device is further set up to create a milling plan for milling off the excess asphalt surface portions on the basis of the at least one second region. The asphalt milling machine is set up to mill off the excess asphalt surface portions in accordance with the milling plan.

[0048] The system for preparing a road for rehabilitation can, for example, have means for transporting away the milled-off portions of the asphalt surface, wherein the asphalt milling machine is further configured to mill through any remaining asphalt surface. The means for transporting away the milled-off portions of the asphalt surface can, for example, have at least one excavator and / or at least one dump truck. The asphalt milling machine is configured to mill through the remaining asphalt surface (after the milled-off portions of the asphalt surface have been transported away). For this purpose, a milling plan can, for example, be created based on the 3D model. The milling plan can specify a time sequence for the milling. The milling plan relates to at least one first and at least one second area of ​​the road. The asphalt milling machine can be controlled in accordance with the milling plan.The milling plan can show a thickness of the remaining asphalt surface that is to be milled through by the asphalt milling machine.

[0049] For example, the method according to the invention may comprise the following further step:

[0050] - Calculating the volume of excess asphalt pavement using the 3D model. Knowing the volume of excess asphalt pavement can further improve rehabilitation planning and lead to more efficient and faster road rehabilitation. For example, the use of resources for removing milled asphalt pavement can be better planned.

[0051] Optionally, the following further step can be provided:

[0052] - Taking at least one core sample from the road to determine at least one reference point for the asphalt pavement layer thickness; the 3D model having the at least one reference point. Taking core samples is a very accurate method for determining layer thicknesses, such as the asphalt pavement layer thickness, but is not non-destructive, typically requires at least one section of road to be closed, and the analysis is also relatively complex. In comparison, the use of geo-radar and an optical measuring method represents a much simpler and cheaper alternative. The accuracy of the 3D model can, however, be improved by taking at least one core sample to reference the asphalt pavement layer thickness at at least one reference point.Optionally, several core samples can be taken, arranged, for example, equidistantly or regularly along the road.

[0053] By way of example, the invention is described according to the following generalized embodiments 1 to 5:

[0054] 1 . Procedure for preparing a road for rehabilitation with the following steps :

[0055] - Providing a 3D model of the road comprising a measured surface and an asphalt surface layer thickness of the road;

[0056] - Comparing the asphalt surface layer thickness in the 3D model with a predefined maximum value in order to determine excess asphalt surface portions of the asphalt surface in the 3D model;

[0057] - Milling off the excess asphalt surface;

[0058] - Removal of the milled asphalt surface parts; and

[0059] - Milling through a remaining asphalt surface.

[0060] 2. Method according to embodiment 1, characterized by the further step before milling off the excess asphalt surface portions:

[0061] - Determining at least one first region and at least one second region of the road in the 3D model, wherein the at least one first region in the 3D model has no excess asphalt surface portions, wherein the at least one second region has excess asphalt surface portions.

[0062] 3 . Method according to embodiment 2 , characterized by the further step before milling off the excess asphalt surface portions :

[0063] - Creating a milling plan for milling off the excess asphalt surface portions based on the at least one second area; wherein the milling of the excess asphalt surface portions is carried out according to the created milling plan. 4. Method according to one of embodiments 1 to 3, characterized by the further step:

[0064] - Calculate the volume of the excess asphalt surface using the 3D model.

[0065] 5 . Method according to one of the embodiments 1 to 4 , characterized by the further step :

[0066] - taking at least one core sample from the road (1) to determine at least one reference point of the asphalt surface layer thickness; wherein the 3D model has the at least one reference point.

[0067] In the following, the invention is described in more detail with reference to drawings, to which, however, it is not intended to be limited.

[0068] Fig. 1A shows schematically a perspective view of a road with a first area and a second area

[0069] Fig 1B-D each show a schematic cross-section of the road with location-dependent asphalt surface layer thickness and excess asphalt surface portions

[0070] Fig. 2A shows a schematic cross section through the road from Fig. 1 with a schematic measuring vehicle

[0071] Fig. 2B shows schematically another cross-section of the road from Fig. 1

[0072] Fig. 3 shows a schematic representation of an asphalt milling machine and a dump truck during milling or removal of excess asphalt surface parts of the road

[0073] Fig. 1A schematically shows a perspective view of a road 1, in this case a highway. The road 1 has a width of 12.5 m and a length of 150 m. The road 1 has an asphalt surface 2 (see Figures 1B-D) arranged on an unbound base course (not shown). An upper side 3 of the asphalt surface 2 forms a surface 4 of the road 1. The surface 3 of the schematically shown road is rectangular in this example and has an area of ​​1875 m 2 (= 12.5 m by 150 m). This corresponds approximately to the maximum area that should lie between two core samples using a conventional testing method. The asphalt surface 2 has an asphalt surface layer thickness 5 (see Fig. 1B) that varies depending on the location along the road 1. Using a conventional testing method based on taking core samples, the asphalt surface layer thickness in the area shown would only be known at one point.

[0074] In this exemplary embodiment, an unbound base layer 21 is arranged beneath the asphalt surface 2. A lower boundary 22 of the unbound base layer 21 is marked by a dashed line. The unbound base layer 21 is located between the asphalt surface 2 and the lower boundary 22. The values ​​given along the road 1 relate to the asphalt surface layer thickness 5 at the respective position. In this exemplary embodiment, the asphalt surface layer thickness 5 varies in a range from a minimum of 7 cm to a maximum of 30 cm. The road 1 has a central reservation 6 which runs centrally along the road 1 and separates two lanes 7 parallel to the direction of travel. Three section lines BB, CC and DD are marked normal to the central reservation 6, along which the cross-sections from Figures 1B, IC and ID run.

[0075] To prepare Street 1 for rehabilitation, the following steps will be carried out:

[0076] - measuring the surface 4 of the road 1 by means of an optical measuring method, in this example by means of a laser scanner 8 (see Fig. 2A);

[0077] - Determining the asphalt surface layer thickness 5 using a geo-radar 9 (see Fig. 2A);

[0078] - Creating a 3D model of the road 1 comprising the previously measured surface 4 and the determined asphalt surface layer thickness 5 ;

[0079] - Comparing the asphalt surface layer thickness 5 in the 3D model with a predefined maximum value in order to determine excess asphalt surface portions 10 of the asphalt surface in the 3D model;

[0080] - Milling off the excess asphalt surface portions 10 ;

[0081] - removal of the milled asphalt surface portions 10a (see Fig. 3); and

[0082] - Milling through a remaining asphalt surface 20 (see Fig. 1B and IC).

[0083] The maximum value in this exemplary embodiment is 14 cm. Accordingly, areas of the road 1 with an asphalt surface layer thickness of 5 up to a maximum of 14 cm do not have any excess asphalt surface portions 10. Areas of the road with an asphalt surface layer thickness of more than 14 cm, in comparison, have excess asphalt surface portions 10, which are shown hatched. The cross sections BB and CC from Figures 1B and 1C run through the second area 12 of the road 1 and show excess asphalt surface portions. The cross section DD from Figure 1D, on the other hand, only runs through the first area 11 of the road 1 and does not show any excess asphalt surface portions 10. The asphalt surface 20 remaining (after the excess asphalt surface portions 10 have been milled off and removed) corresponds to the asphalt surface 2 without the excess asphalt surface portions 10, i.e.for example the part of the asphalt surface 2 which is shown without hatching in Figures 1B to 1D.

[0084] In this exemplary embodiment, the following further step is carried out before milling off the excess asphalt surface portions 10:

[0085] - Determining at least one first region 11 and at least one second region 12 of the road 1 in the 3D model, wherein the at least one first region 11 (region without hatching) in the 3D model has no excess asphalt surface portions 10, wherein the at least one second region 12 (shown hatched) has excess asphalt surface portions 10. In this exemplary embodiment, the road 1 has exactly one first region 11 and exactly one second region 12. Alternatively, the road can also have several first regions 11 and / or second regions 12. In addition, the following further step is carried out before milling off the excess asphalt surface portions 10:

[0086] - Creating a milling plan for milling off the excess asphalt surface portions 10 based on the at least one second region 12; wherein the milling of the excess asphalt surface portions 10 is carried out in accordance with the created milling plan.

[0087] In addition, a volume of the excess asphalt surface portions 10 is calculated using the 3D model in order to further improve the planning of the rehabilitation by precisely estimating the amount of material to be removed.

[0088] Parallel to the central reservation 6 , two further section lines E - E and FF are marked , along which the cross sections from Figures 2A and 2B run .

[0089] Fig. 2A shows a cross-section through road 1 along section line EE (see Fig. 1A). On the road, a device for creating the 3D model of road 1 is schematically shown, comprising:

[0090] - having a measuring vehicle 13

[0091] - an optical measuring device 14 , in this example a laser scanner 8 , for measuring the surface 4 of the road 1 ; and

[0092] - a geo-radar 9 for determining the asphalt surface layer thickness 5 of the road 10 ;

[0093] - a data processing device (not shown since in this example it is arranged within the measuring vehicle) which is set up to create a 3D model of the road 1 comprising the previously measured surface 4 and the determined asphalt surface layer thickness 5. The data processing device is further set up to compare the asphalt surface layer thickness 5 in the 3D model with the predefined maximum value in order to determine excess asphalt surface portions 10 of the asphalt surface 2 in the 3D model. In this exemplary embodiment, the measuring vehicle 13 has a car 19. The geo-radar 9 is attached to the car 19 and has a substantially constant distance to the surface 4 of the road 1 while the measuring vehicle 13 is moved over the road 1. Furthermore, the laser scanner 8 is attached to the car 19 in order to measure the surface 4 of the road 1.In this exemplary embodiment, the laser scanner 8 is an RD-MI scanner from Topcon Deutschland Positioning GmbH. The measuring vehicle 13 records a position of the measuring vehicle 13 while measuring the surface 4 of the road 1 using a global navigation satellite system (GNSS, in this example GPS). Optionally, alternatively or additionally, the geo-radar 9 can also be equipped with a GNSS antenna in order to be located using a satellite system. The measuring vehicle 13 travels over the road 1 at up to 80 km / h in order to measure the surface 4 of the road 1 and to determine the asphalt surface layer thickness 5.

[0094] Fig. 3 shows a perspective view of an asphalt milling machine during the milling of excess asphalt surface portions 10 from a road 1. The asphalt milling machine 15 has a rotating milling drum (not shown) equipped with milling tools (so-called chisels). In this example, the asphalt milling machine 15 is a 3D-controlled asphalt milling machine that can be controlled without a driver according to the milling plan or can operate autonomously.

[0095] A system for preparing the road 1 for rehabilitation has the device for creating a 3D model of the road (see Fig. 2A) and additionally the asphalt milling machine 15. The data processing device is set up to determine at least a first area 11 and at least a second area 12 of the road 1 in the 3D model, wherein the at least one first area 11 in the 3D model has no excess asphalt surface portions 10, wherein the at least one second area 12 has excess asphalt surface portions 10. The data processing device is further set up to create a milling plan for milling off the excess asphalt surface portions 10 on the basis of the at least one second area 12, wherein the asphalt milling machine 15 is set up to mill off the excess asphalt surface portions 10 in accordance with the milling plan.

[0096] The system for preparing the road 1 for rehabilitation further comprises means for transporting away 16 the milled-off asphalt surface portions 10a, wherein the asphalt milling machine 15 is further configured to mill through the remaining asphalt surface 20. The material of the (milled-through) remaining asphalt surface 20 thus prepared is then mixed with a binding agent such as lime or cement, in this example cement, and in turn used as a base course for the rehabilitation road. The means for transporting away 16 the milled-off asphalt surface portions 10a comprise a dump loader 17 in this exemplary embodiment. In this exemplary embodiment, the asphalt milling machine 15 is configured to convey the milled-off asphalt surface portions 10a directly into the dump loader. For this purpose, the asphalt milling machine 15 has a conveyor device 18.Alternatively, the asphalt milling machine 15 can be configured to unload milled or milled-through asphalt surface portions 10a directly onto the remaining road.

[0097] Fig. 2B shows (similar to Fig. 2A) a sectional view of the road from Fig. 1 along a section line FF.

Claims

Claims 1. Procedure for preparing a road (1) for rehabilitation comprising the following steps: - measuring a surface (4) of the road (1) by means of an optical measuring method, in particular by means of a laser scanner (8); - Determining an asphalt surface layer thickness (5) by means of a geo-radar (9); - Creating a 3D model of the road (1) comprising the previously measured surface (4) and the determined asphalt surface layer thickness (5); - comparing the asphalt surface layer thickness (5) in the 3D model with a predefined maximum value in order to determine excess asphalt surface portions (10) of the asphalt surface (2) in the 3D model; - milling off the excess asphalt surface parts (10); - removal of the milled asphalt surface parts (10a); and - Milling through a remaining asphalt surface (20) .

2. Method according to claim 1, characterized by the further step before milling off the excess asphalt surface portions (10): - Determining at least one first region (11) and at least one second region (12) of the road (1) in the 3D model, wherein the at least one first region (11) in the 3D model has no excess asphalt surface portions (10), wherein the at least one second region (12) has excess asphalt surface portions.

3. Method according to claim 2, characterized by the further step before milling off the excess asphalt surface portions (10): - Creating a milling plan for milling off the excess asphalt surface portions (10) on the basis of the at least one second region (12); wherein the milling off of the excess asphalt surface portions (10) is carried out in accordance with the created milling plan.

4. Method according to one of claims 1 to 3, characterized by the further step: - Calculating a volume of the excess asphalt surface portions (10) using the 3D model.

5. Method according to one of claims 1 to 4, characterized by the further step: - Taking at least one core sample from the road (1) to determine at least one reference point of the asphalt surface layer thickness (5); wherein the 3D model has the at least one reference point.

6. Device for creating a 3D model of a road (1) comprising: - having a measuring vehicle (13) - an optical measuring device (14), in particular a laser scanner (8), for measuring a surface (4) of the road (1); and - a geo-radar (9) for determining an asphalt surface layer thickness (5) of the road (1); - a data processing device which is designed to create a 3D model of the road (1) comprising the previously measured surface (4) and the determined asphalt surface layer thickness (5), wherein the data processing device is further designed to compare the asphalt surface layer thickness (5) in the 3D model with a predefined maximum value in order to determine excess asphalt surface portions (10) of the asphalt surface (2) in the 3D model.

7. System for preparing a road (1) for rehabilitation, comprising the device for creating a 3D model of the road (1) according to claim 6, with an asphalt milling machine, wherein the data processing device is designed to determine at least a first area (11) and at least a second area (12) of the road (1) in the 3D model, wherein the at least one first area (11) in the 3D model has no excess asphalt surface portions (10), wherein the at least one second area (12) has excess asphalt surface portions Portions (10), wherein the data processing device is further configured to create a milling plan for milling off the excess asphalt surface portions (10) on the basis of the at least one second region (12), wherein the asphalt milling machine (15) is configured to mill off the excess asphalt surface portions (10) in accordance with the milling plan.

8. System for preparing a road (1) for rehabilitation according to claim 7, comprising means for transporting away (16) the milled asphalt surface portions (10a), wherein the asphalt milling machine (15) is further configured to remove a remaining to mill through the asphalt surface (20).

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