EP4473161A1

EP4473161A1 - Road with reinforced roadside

Info

Publication number: EP4473161A1
Application number: EP23706442.3A
Authority: EP
Inventors: Hannes NIEDERKOFLER
Original assignee: Stratec Rt Srl
Current assignee: Stratec Rt Srl
Priority date: 2022-02-02
Filing date: 2023-01-27
Publication date: 2024-12-11
Anticipated expiration: 2043-01-27
Also published as: EP4473161C0; US20250129552A1; EP4473161B1; WO2023148592A1; CA3247939A1

Abstract

The field of application of the present invention relates to the best practices that can be adopted in the construction of roads, also taking into particular consideration the fact that not only the road surface needs adequate consolidation, as it is normally done, but also the docks. In fact, the roadside must be considered part of the "road system", and its characteristics have a great influence on the overall road safety. In particular, the "road system" according to the invention provides that, before laying the asphalt surface, a reticular mesh structure is laid over the road surface made up of material with good tensile strength, and this reticular structure is designed to cover the entire roadbed from side to side in its width, and to protrude significantly beyond the area in which it is envisaged to lay the asphalt, so that, once the asphalt has been laid, said reticular structure protrudes from the asphalted roadway so as to cover, at least in part, even the roadside. Furthermore, said reticular structure, in its edges, which, after installation, run parallel to the edge of the road, and externally to the paved site, is designed to facilitate the firm coupling of other elements of the "road system". Said reticular mesh structure 300 is retained by the overlying road surface 210, but not only. In fact, since it envelops the entire strip of the elevated ground on which the road is built, it allows the entire mass of terrain on which the entire "road system" is built to collaborate in the overall resistance. It is thus proposed a "road system" in which parts that have historically been conceived in a substantially autonomous way (ground substrate platform, paving, and safety barriers) collaborate synergistically in the creation of a safe "road system" as a whole.

Description

TITLE: ROAD WITH REINFORCED ROADSIDE

DESCRIPTION

Technical field of the Invention

In general, the field of application of the present invention concerns the best practices that can be adopted in the construction of roads, taking into particular consideration also the fact that the need of adequate consolidation, does not concern just the road bed, as normally happens, but also the docks.

In fact, the roadside must be considered part of the "road” intended as a system, and its characteristics have a great influence on road safety as a whole.

Prior Art

The so-called yielding docks are in all respects considered a dangerous factor for road traffic, so much so that special signs are provided which should warn travelers about it, when the roadside where they are traveling is not adequately stabilized, and presents risks of subsidence. Furthermore, the road quays, or the edge of the road in general, constitute the place for the installation of the safety barriers, also called "guardrails" (a term that will be mainly used in the following of this description).

These barriers are an essential element in ensuring road safety. In fact, in addition to clearly delimiting the edge of the road, they have the purpose of significantly reducing the consequences of accidents involving vehicles going off the road.

The main function of a "guardrail" is therefore to ensure the safety of a road: for this they must comply with adequate mechanical standards. These standards, which allow the barrier to be defined as "compliant", must be certified. Typically, this takes place through real tests (hereinafter also called "crash-tests"), by subjecting a "guardrail", created in a real installation context, to collisions with vehicles. It should be noted that a correct interpretation of the standard should concern not only the safety barrier as such, but also its installation: in essence, although the manufacturers of road barriers supply their barriers with certification, the barrier alone does guarantee road safety, but the whole system composed of the road and the barrier (as it is installed in the different real cases).

Common practice, based on the prior art, does not adequately consider these safety aspects, and it is not uncommon that, in the event of an accident, the subject who manages the road is responsible for the consequences of such an accident.

In fact, it is quite frequent that the "guardrails" installed along the roads do not meet the technical safety requirements according to the standard, because their installation does not reflect the certification conditions, with serious risk for the consequences of any accidents.

After all, the huge variety of installation conditions makes it very difficult to build roads in which the installation conditions of the "guardrail" are homogeneous.

In summary, it can be stated that the prior art is satisfactory from the point of view of the materials and elements that are used to make the "guardrail", intended as a product certified by authorized bodies, while the aspect that regards its installation, which often does not replicate the certification conditions of the "crash-test", still remains substantially unresolved.

In conclusion, a good number of installed "guardrails" do not meet the real safety requirements, due to installation discrepancies, and this installation discrepancy is substantially due to the large variety of mechanical characteristics that can be guaranteed by the road quays.

In fact, the stability of the installation largely depends on the compactness and the characteristics of the ground which, if not particularly compact, modifies the behavior of the road barrier in the event of a vehicle collision: in this case, in fact, the uprights, not being firmly fixed in the ground, following an impact with a vehicle, they will tend to rotate rigidly in the ground, instead of bending, this behavior reduces their deformation capacity and therefore their ability to absorb and dissipate the necessary amount of kinetic energy. Moreover, the uprights fixed to the ground normally have very different behaviors depending on the trait of road in which they are planted, with consequent different performances with respect to the safety they can guarantee.

The prior art proposes some solutions which aim to overcome this problem linked to installation inhomogeneities. Some, particularly interesting, envisage the use of anchors that grip the ground below the road surface. The interest derives from the fact that the soil under the road surface is normally compacted in order to avoid subsidence of the roadway due to the weight of passing vehicles. It is clear that such an inconvenience (i e., the subsidence of the roadway) must be absolutely avoided, and therefore the foundation on which the roads are built is always suitably prepared and, in particular, it is pressed so as to make it compact.

Solutions of this type are taught in patent applications n. PCT/IB2019/050262 [“Reinforcement element for fixing at the base, in ground, the uprights of roadside safety barriers”] and n. PCT/IT2020/000075 [“Road equipped with road safety barriers fixed to the ground and installation method thereof”] (by the same authors of the present patent application).

In these patent applications, a post is indicated which is connected, by means of a joint element, which works under tension, to one or more plates buried under the road surface. Indeed, in the second patent application, some expedients are envisaged which allow adjustments to be made so that the mechanical performance of the "guardrail" can be adapted to the various installation contexts. These solutions, in their generality, are conceptually quite simple, and are consistent with the view according to which a road, for the purposes of its safety, must be conceived as a single system, and not the result of a combination of independently designed subsystems (road surface, paving, “guardrails” etc.).

Another solution, which is based on the exploitation of the greater compactness of the soil under the roadway is taught in WO 2019/008525 A1 [“Device for anchoring safety road barriers poles to the ground”]. This is a solution that provides for a helical element, the cost of which is presumably very significant compared to the cost of the other elements of the "guardrail"; this element is suitable for being inserted into the ground by means of a screwing maneuver.

The anchoring system taught in WO 2019/008525 A1 presents problems similar to those of the previous solutions and, moreover, in cases where it is most needed (i.e., when the roadside is not very compact, and does not offer adequate resistance), it must penetrate a lot deep into the ground beneath the roadway, in a zone that is often occupied by underground utilities.

It is decidedly preferable that the "road system" as a whole, including the suitably installed safety barriers, does not invade the ground below the roadbed (approximately up to a depth of the order of one meter): this in order to decouple, as much as possible, the management of underground utilities (often associated with roads) from road management.

However, in the real implementation of the teachings proposed in the patent applications mentioned above, although it is possible to achieve improvements in safety, no substantial interventions are envisaged in the consolidation of the quay, which is normally treated as a given context with which it is necessary to live. In fact, the focus is on how to exploit the compacted soil of the roadbed, but the fact that the mechanical performance of the road quay could also be improved is not exploited in any way, also considering the quays, to all intents and purposes, as part of the "road system", and as such, parts of the system to be actively exploited to ensure traffic safety.

The consolidation of the roadside is an intervention to which, as mentioned, too little attention is still paid: when it is tackled, it is managed only when a new road is being built, or when overall road reconstruction works are undertaken, i.e., on occasions when even the road surface is in some way redeveloped with new pressing and compaction actions.

In many cases, however, the consolidation of the terrain along the roadside is practically not possible: this occurs when the roadway is elevated with respect to the surrounding land, and the embankment that corresponds to the roadside is too narrow. The construction of roads slightly elevated with respect to the surrounding land is a good construction practice, as it facilitates good drainage, however, in all these cases, there is the contraindication that the roadside does not offer ground with good consistency characteristics.

Narrow and relatively fragile embankments, not only pose problems in installing the "guardrails", but also give rise to the presence of a yielding quay, i.e., a feature that increases the danger of the road.

Ultimately, even though the known art proposes solutions which, although not very widespread, are certainly effective for tackling the problem of fixing the single uprights of a "guardrail" to the ground, also taking into account the different installation conditions, it can be conclude that an overall "road system" still needs, in many real and widespread cases, additional solutions aimed at improving road safety and stability. In particular, the fixing of safety barriers is perceived as a major problem, especially in cases where the roadside is not sufficiently compact and solid, and the proposed solutions are mainly oriented towards looking for anchor points under the road surface, where the ground is more compact. Only in a few cases, and in particular circumstances, roadside consolidation works take place. When this is done, they are expensive works, such as the construction of curbs which involve works of a certain complexity.

The perspective in which the present patent application is framed, as will be evident from the continuation of the present description, is in itself innovative, and consists in not considering the safety barriers as a separate element to be installed on the roadside to improve safety, but in conceiving an overall "road system", which also includes the safety barriers and the roadside itself. And the safety of this "road system" depends on all its elements, on how they are installed and built, and on how they integrate with each other.

Description of the Invention

The main purpose of the present invention, therefore, is to indicate a new road construction technique, possibly using new materials, and suitable for creating a "road system" in which the roadside is very consistent, and lends itself to accommodating the installation of safety barriers being able to count on fairly homogeneous fixing characteristics.

In particular, it is very important to obtain a roadside with good characteristics of consistency and safety especially in roads with a raised seat with respect to the surrounding land, and above all when the so-called "bank" is quite narrow. That is, how quickly the land along the roadside degrades from the edge of the paved part of the road.

Other purposes of the present invention consist in indicating a new technique for constructing roads which, while using materials already offered by the known art, or materials with modifications that are easy to implement with respect to what already exists, allow to create a safe "road system", conceived in an innovative way, in which the roadway itself, as well as the quays (i.e. the roadside), as well as the safety barriers and signs, they are all conceived as a whole, so as to create a "road system ” characterized by the best possible security. In particular, this construction technique of a "road system" (understood in the sense indicated above) must present particular safety requirements in roads with raised seats with respect to the surrounding terrain.

Furthermore, this technique must also be able to be implemented on all occasions in which an intervention to renovate the road surface of existing roads takes place.

Finally, a further purpose of the present invention consists in indicating a "road system" in which a possible certification, based on actual tests ("crash test") in a test environment, is a realistic certification; and the outcome of the tests is effectively representative of the performance in real conditions, in cases of accident in which one or more vehicles go off the road

These objectives can be achieved by a "road system" including a roadbed, an asphalted road surface above, a roadside not covered with asphalt and at least one portion of safety barrier installed on said roadside; being said "road system" characterized in that it also comprises a reticular mesh structure made up of material with good tensile strength, and suitable for being interposed under said asphalted road surface and above the road substrate, as well as above said roadside, and being this reticular mesh structure designed to cover the road substrate from side to side in its width, and to protrude beyond the area in which the asphalted road surface is to be laid; that is, with the asphalt laid, said reticular structure protrudes from the asphalted roadway so as to invade, at least in part, also the roadside.

Furthermore, said reticular structure in the areas which, after installation, emerge above said roadside, has road-edge coupling points which are arranged in a row, at alternating distances or parallel to the asphalted edge of the roadway, and in its immediate vicinity, as said road-edge coupling points are designed to facilitate the firm attachment of other elements of the "road system".

Brief Description of the Drawings

The main advantage of the present invention consists in the fact that any "road system" created according to the teachings of the present invention satisfies all the main requirements for which it was conceived, designed and certified Moreover, this invention also has further advantages, which will become more evident from the following description, from some examples of practical embodiments, which illustrate further details, from the attached claims which form an integral part of the present description, and from the attached figures in which: Figures 1 a and 1b show the main elements of a road safety barrier (a "guardrail") according to the prior art; Figures 2a and 2b show a "guardrail" according to the prior art, fixed to the base by infixion of the uprights into the ground, shown in two different installation cases; Figure 3 shows a synthetic overall view of a raised roadway, built according to the current practice; Figures 4a and 4b show a synthetic overall view of a raised roadway built according to the invention.

Detailed Description

Figure 1 a shows a portion of a typical road safety barrier (also called "guardrail"), indicated as a whole with the number 100. This barrier is seen from inside the road and, in general, it is made up of the elements listed below:

• substantially vertical elements, normally called uprights, which support the barrier itself, and indicated (always, and also in the following figures) with the number 110;

• a horizontal containment metal strip, indicated with the number 130 also called horizontal blockout bar;

• an eventual upper beam, indicated with the number 140.

The uprights 110, in a typical and widespread installation method, are fixed to the base by driving them into the ground. The number 200 indicates the ground where the "guardrail" is installed, in the cases considered by the present invention.

Said horizontal blockout bar 130 is only partially shown in the figure since it is a very long element which, in addition to carrying out the function of containment of the vehicles, connects a sequence of uprights 110 to each other, also giving them greater resistance. In fact, if one or more uprights 110 were to be torn apart by the effect of a violent impact from a vehicle, said horizontal blockout bar 130 would remain connected to the other uprights 110, in any case containing, albeit to a lesser extent, the exit of the vehicle. Since it is an element of non-predefined length, said horizontal blockout bar 130 is necessarily composed of a sequence of segments connected to each other. Numbers 131 and 132 in Figure 1a show two segments of the horizontal blockout bar 130 connected to each other by bolting, as occurs in the vast majority of cases. In the case of Figure 1a, this bolting is performed with four bolts indicated with the number 133; however, other connection methods are also possible; what matters is that the connection between the segments is very solid, so that the horizontal blockout bar 130 behaves substantially as a single and continuous body, able to guarantee the appropriate certified mechanical performance.

Figure 1b represents the same "guardrail" 100 shown in Figure 1a, but it is seen in a section orthogonal to the direction of the road, wherein the numbers indicate the same elements as in Figure 1a.

Figure 1b also allows the view of a spacer element between the upright 110 and the horizontal blockout bar 130. Said spacer element is indicated with the number 120, it has the main function of connecting the horizontal blockout bar 130 with the upright 110, and plays an important role in determining the performance of the guardrail as a whole.

Another feature, which can be appreciated from the view of Figure 1 b, is the profile of the horizontal blockout bar 130. This profile is the result of a long evolutionary process and has the advantage of guaranteeing an excellent compromise between mechanical performance and costs, reason why said horizontal blockout bar 130 is a very consolidated element, wherein its operating principles have not been the subject of many innovations in recent times.

It has already been stated that the mechanical performances of road safety barriers according to the known art are satisfactory when these can operate in nominal conditions, because only in such conditions all the parts of the "guardrail system" (meaning all its component parts briefly summarized with the help of figures 1) work according to the design specifications when an accident occurs, and the barrier is subjected to strong impacts. The nominal conditions are those which correspond to the test conditions during the so-called "crash-test". There are various ways in which the performance of a "guardrail" can be tested: ranging from laboratory tests to real tests in which a real vehicle simulates an accident and hits the "guardrail". The real-life tests are certainly the most significant ones, as they clearly show whether the "guardrail" performs its function of containing a vehicle that is going off the road and stops its movement at a point which minimizes the dangerous consequences of the simulated accident. This containment function always requires the complete dissipation of the kinetic energy of the vehicle involved in the accident, and this dissipation can occur in many ways: through the plastic deformation of the "guardrail", or through the breakage of parts of the same. In some cases, it is required that the "guardrail" does not detach from the ground where it is installed, while in other cases, some uprights can also detach from the ground and the containment takes place due to the effect of the resistance of the horizontal blackout bar which remains hooked to a plurality of uprights, some of which, when stressed by an impact of a mass with a reduced momentum, do not detach from the ground.

Ultimately, the optimal "guardrail" is the one that performs its function in the best possible way, and its behavior depends not only on the "guardrail" as such, but also on the type of road and the characteristics of the ground on which it is fixed.

Finally, in Figure 1b, above the ground 200, the road surface is also shown, indicated with the number 210, which typically consists of a layer of asphalt with a thickness of the order of ten centimeters.

Figure 2a illustrates the behavior of a "guardrail" infixed on the ground on the embankment of a road where the roadway is raised above the surrounding terrain. This type of raised road is very typical and, in the vast majority of real cases, the uprights 110 of a "guardrail" are simply driven into the ground 200 without paying particular attention to the characteristics of the ground 200 Therefore, when the "guardrail" is hit by an impact force, indicated in Figure 2a with the number 400, the embankment is often too yielding, typically it is not sufficient compact to hold vertical the upright 110, which does not deform, and rotates as indicated in Figure 2 (in which the rotated position of the post 110 is shown with a dotted line).

Figure 2b instead shows a detail of a road equipped with a safety barrier in which there are some reinforcing elements with the function of firmly keeping the fastening to the ground of the upright 110.

Compared to Figure 2a, in which the characteristics of the ground 200 were not substantially relevant (since they were not adequately taken into account for the installation of the "guardrail"), the ground is instead depicted in greater detail. In fact, the number 201 indicates a zone where the terrain has different characteristics with respect to the generic land 200. In fact, the roadway on which a road is normally built (practically always) undergoes a stabilization treatment by means of compaction (by pressing) of the soil on which the road surface is then laid. In fact, a so-called "roadbed" is always created, the depth of which is of the order of a meter (generally the "roadbed" is designed according to the geological characteristics of the soil 200 on which the road is built). Said "roadbed" 201 is essential, and serves to prevent subsidence phenomena of the road when it is loaded with the weight generated by vehicular traffic. Being a treated ground, said "road bed" 201 it has known characteristics of compactness, in general very good, because, as mentioned, it is a ground that must not deform under the weight of vehicles passing on the road. Said "roadbed" 201 is obviously found under the road surface, always indicated with the number 210; certainly, a part of terrain treated as the "road bed" also extends towards the roadside, but its characteristics along the edges are certainly not controlled like those below the road surface, and, in any case, they are affected by the characteristics of the surrounding terrain 200.

The "roadbed" 201 therefore represents the ideal ground for anchoring the uprights 110 for the installation of safety barriers. Anchors of this type are known, for example from patent application no. PCT/IT2020/000075 - “Road equipped with road safety barriers fixed to the ground and installation method thereof” (by the same authors of this patent application and already mentioned above).

The system taught in the cited patent application is summarized in figure 2b and has a particular composition as it includes at least three distinct and interconnected subsystems: a system of vertical plates, indicated with the number 153, a connecting rod, indicated with the number 152, and a junction element, indicated with the number 151. Said system of vertical plates 153 is arranged to be driven vertically into the road surface 201 , where the terrain is more compact, in an area below the road surface 210, possibly not too close to the edge of the road, and in any case in an area where 201 “roadbed” holding performance is reliable.

Said connecting rod 152 is an element that works in tension being connected to said system of vertical plates 153 on one side and to an upright 110 on the other, even if, as will be clarified below, the connection with the upright 110 is indirect. The function of said connecting rod 152 is to hold the upright 110 to which it is connected in the installed position, when the latter is urged by an impact force, always indicated with the number 400, and coming from the road.

The joint between an upright 110 and a connecting rod 152, as already anticipated, is not a direct joint: it is implemented through said joint element 151 , whose functions are more than one: in fact, in addition to guaranteeing the joint between an upright 110 and a connecting rod 152, allows the use of extremely simple uprights, such as those typically used in implementations according to the prior art, which can be installed by infixion, using a pile driving machine, and which do not require particular configurations to hook up to said connecting rod 152

Furthermore, and these are perhaps the most important characteristics: said junction element 151 is a rather small element, which is located near the base of the uprights 110, in an area not covered by the road surface, therefore it is an element on which maintenance operations are easy, and it is an element that can be sized to break when stressed by predetermined forces.

In particular, said joining element 151 must break before said connecting rod 152 breaks and before said system of vertical plates 153 moves due to the effect of a particularly high impact force 400 which, acting on the upright 110 towards the outside of the road could drag the whole system of vertical plates 153.

In short, it is possible to concentrate on said junction element 151 , all the adjustments on the mechanical performance that are intended to be obtained with regard to the behavior of a "guardrail" in the event of a collision. The mechanical performances of the anchoring systems such as the one shown in Figure 2b are substantially due to the particular compactness of the soil of which the "roadbed" 201 is made up, which is located below the road surface 210, while other characteristics of the " road system", as a whole, are not exploited. Furthermore, any yielding of the roadsides continues to depend only on the consistency of the ground 200, which is often not very compact.

Figure 3 shows a section of a raised road, as there are many in real cases. These types of roads are characterized by the fact that the roadway is placed on a strip of raised ground: normally this is ground brought specifically to create this raised strip, and it is indicated in Figure 3 with the number 200, to indicate, as in the previous figures, that it is more or less compact soil whose mechanical characteristics are not, however, accurately controlled.

As happens in almost all other roads (that is, even those that are not built on a raised site), however, before carrying out the laying of asphalt, the ground is prepared so that it does not undergo deformations, too easily, when subjected to the load of the passage of vehicles, and to prevent excessively accentuated subsidence phenomena from occurring.

Therefore, a substrate is prepared, using appropriate materials, and, above all, the roadway is compacted subjecting it to pressing treatments with particular machinery, also called "stone crushers", very heavy, which through repeated passages press and compact the soil.

Thanks to these treatments, a “roadbed” is formed, indicated with the number 201 whose characteristics can be considered known with a good approximation.

Only in cases where the raised site is significantly wider than the width of the paved road it is possible to treat the soil to make it compact even along the roadside, outside the area to be paved. Figure 3 shows a typical case in which the asphalt surface, always indicated with the number 210, occupies almost the entire width of the raised section, and the roadside quay is relatively narrow. In these cases, which are often referred to as narrow embankment, the roadside ground is generally not suitable for the installation of safety barriers by driving the uprights. Furthermore, if loaded with significant weights, the roadside quay can even yield and even collapse.

Ultimately, the situation synthetically represented in Figure 3 is a typical situation, and the highlighted contraindications represent real possible cases of safety risk. Other typical situations, in which one finds himself in the presence of roads with narrow embankments, concern the cases of roads built on mountain layouts, in which at least one side of the road faces the sloping side of a hill, or in roads which flank watercourses such as, for example, ditches or canals.

In short, the cases of roads which have a narrow embankment and which, therefore, do not have a site on which to install the safety barriers with the necessary reliability are far from rare, and they are cases particularly subject to the risk of having a yielding quay, at least in some stretches.

Figure 4a shows, in a very schematic and essential way, a technique for preparing the road surface according to the teachings of the present invention.

Figure 4a shows the stretch of road already presented in Figure 3, in which the asphalt surface has not yet been laid. Therefore, we see the strip of raised ground, indicated with the number 200, already treated with the preparatory operations for the subsequent paving for asphalting; for which the part of land that constitutes the road substrate (or “roadbed”), again indicated with the same number, 201 , has controlled (and generally quite good) mechanical characteristics.

The present invention provides that before completing the laying of the pavement, i.e., the laying of the asphalt surface, the strip of raised ground is covered by a reticular mesh structure, indicated with the number 300.

Said reticular mesh structure 300 can be positioned directly on the compacted ground of the “roadbed”, or, since the road surface is generally made up of several layers of different composition, the reticular mesh structure 300 can also be laid over the first layers of casting of the road surface, or over the layers that are found at greater depth.

In any case, an important mechanical characteristic of said reticular mesh structure 300 consists in offering a good tensile strength.

The fact of reinforcing the roadbed with some sort of armor, although not a frequent practice, is nonetheless a known practice. The use of inextensible meshes or sheaths, to be laid under the road surface, allows the road surface to be consolidated, counteracting the formation of cracks or deformations. There are therefore already products designed specifically to further reinforce the roadway against deformations having horizontal components.

What does not exist is a similar product that has the additional characteristics that are necessary to consolidate the overall so-called "road system", including roadside quays and safety barriers. In Figure 4a, two important characteristics of the reticular mesh structure 300 according to the invention can be appreciated: the first characteristic is that said reticular mesh structure 300 must extend beyond the surface which will be asphalted, the second characteristic consists in the fact that it must be prepared to hook other elements, such as elements to be fixed along the roadside, or other pieces of meshed structure, to also cover more external areas of the embankment.

In Figure 4a, these coupling points are indicated with the numbers 310 or 320: in fact, there are distinct coupling points which must be present; some roadside hooking points must surface near the asphalted edge of the road, indicated with the number 310, while further edgemesh hooking points, indicated with the number 320, are positioned on the outermost edges of said reticular mesh structure 300.

Said roadside hooking points 310 are designed to hook elements of the "road system" which must be installed in the immediate vicinity of the asphalted roadway, and in particular the uprights of the "guardrails". The roadside coupling points 310, once installed, emerge above the roadside, and are arranged in a row, parallel to the paved roadway (as shown in the figure), or at alternating distances from the paved edge, but always substantially in row (albeit a so-called “zig-zag” row). Said additional edge-mesh hooking points 320, when present (for example because the meshed network structure 300 protrudes far beyond the asphalted area, and abundantly covers the roadside) are arranged to hook additional ground cover elements to it, in order to extend the covered ground area outside the paved road. Or, said further edge-mesh hooking points 320 are arranged to apply elements for fixing said reticular mesh structure 300 to the ground, such as for example ground fixing pegs. Obviously, the presence of said additional attachment points on the edge of the mesh 320, external to the row of attachment points 310, occurs in cases in which said reticular mesh structure 300 protrudes well beyond the asphalted area so as to significantly cover the edge of the street.

Figure 4b shows the same stretch of road presented in Figure 4a, in which, however, the asphalt surface 210 has already been laid. Furthermore, in Figure 4b it can be seen that alongside the asphalted area (i.e., covered with the asphalt surface 210) there is an area which corresponds to the so-called roadside, and which is indicated with the number 220.

Said roadside 220, in a very large number of cases, is not covered by any pavement, and the consistency of the soil of which it is made up does not have homogeneous characteristics along the entire road layout.

From the representation of Figure 4b, the advantageous technical effects, which can be offered by a reticular mesh structure 300 according to the teachings of the present invention, are evident. In addition to the technical effects of better cohesion and resistance of the road surface which are known effects and, as such, not relevant for the purposes of a request for patent protection, it is evident that every object fixed on the roadside, being also able to hook to said hooking points 310, at the edge of the road, become very difficult to move laterally as it is held by the entire reticular mesh structure which, as mentioned, has good tensile strength.

Said reticular mesh structure 300 is, in turn, retained by the overlying road surface 210, but not only. In fact, since it wraps around the entire strip of raised land on which the entire "road system" is built (or clings to it if the reticular structure is not so wide as to significantly wrap around this strip of raised land) , said reticular mesh structure 300 allows the whole mass of land on which the "road system" is built to collaborate with the overall cohesive strength of the entire "road system", eventually transmitting the stress up to the opposite side of the road where the structure can be anchored to the elements that are on that side.

The characteristics indicated with the aid of Figures 4a and 4b are essential for the purpose of defining the present invention, which however lends itself to a large number of implementation variants. A feature which increases the effectiveness of the invention is that the reticular mesh structure 300 which must cover the strip of land on which the "road system" according to the invention is built is very large, so that in the event of mechanical stress the tension is discharged over a large area of the structure itself.

In general, the laying of the reticular mesh structure 300 can take place by laying large pieces of this structure one after the other, covering stretches of road even of several kilometers, and consecutive pieces can be sewn together so as to obtain the continuity of the structure itself.

In particular, it is recommended that the mesh structure is transversely continuous, i.e., that it crosses the road from edge to edge, protruding beyond the area covered by asphalt, possibly so as to abundantly cover the roadside as well; while the continuity of this reticular structure in the direction of the length of the road, while certainly useful, is in any case less important.

These reticular structures do not need to be rigid, therefore they lend themselves to being supplied in the form of rolls, and therefore also in very large sizes; Furthermore, continuity even on long stretches of road can be obtained by joining, or sewing together, the various patches laid on the surface to be covered

Even the laying of the reticular mesh structure 300 can take place according to some variants. In fact, the paving of roads, on which there is no need to dwell here, generally provides for the laying of some layers of materials with different characteristics, and the reticular mesh structure 300 can be laid at various levels. The important thing is that, when the asphalt is completed, the mesh structure 300 protrudes from both sides and is well below the upper external surface of the asphalt.

In preferred embodiments, the structure can be located below the part of the road surface which is removed by milling (i.e., below the topmost layer of asphalt), when the road is resurfaced for maintenance purposes. In this way the structure remains intact even during various resurfaces. Only when the roadway is excavated deeply, either to access utilities or for a very general resurfacing of the road, the mesh structure is removed, and then, it has to be replaced or restored. In other embodiments, the mesh structure may actually consist of two, or more, mesh structures laid at different levels of depth. The materials used to make said reticular mesh structure 300 can also be different, and can give rise to different embodiments. In an interesting implementation form, the reticular mesh structure can be obtained by modifying one of the various existing products, currently used to make the road surface more cohesive and to limit the deformations of the road surface.

In fact, as already mentioned above, in the present description, various products exist and are commercially available: they range from metal structure meshes to polyester or glass fiber meshes with polymer coatings; the latter products have the not negligible advantage of being disposable in an undifferentiated way with respect to the road surface, simplifying the operations of milling and removal of asphalt during the resurfacing that must periodically be done on the roads. In any case, all the materials used by the products currently offered to strengthen the road surface, improving its cohesion, always have a good tensile strength and blend optimally with the road surface itself: therefore, they are certainly excellent candidates to provide a starting point for the implementation of the present invention too.

The forms of implementation made with metal meshes, or with combinations of different materials, both synthetic and natural, are also interesting

In general, it is strongly recommended to choose materials compatible with the composition of the asphalt, so that said reticular mesh structure 300 merges with the road surface 210, avoiding that the structure itself acts as a separating element between the surface and the roadbed, or between different layers of the road surface. Ultimately, it is reiterated that it is preferable that the introduction of said reticular mesh structure 300 does not modify the adhesion characteristics of the road surface with respect to the conditions that would occur in the absence of this reticular mesh structure 300.

Also with regard to the attachment points 310 or 320 it is possible to implement the invention according to innumerable variations.

If the reticular mesh structure, for example, is quite dense, the weave of the structure itself can directly provide attachment points; however, it is useful to provide specially prepared points to withstand even very strong and impulsive tractions, unloading them in an optimal way on the greatest possible number of fibers making up the reticular structure. Therefore, it is possible to exercise ingenuity to conceive innumerable textures of the structure in order to make the greatest number of fibers converge on the attachment points.

It should be noted that the geometry of the weave of said reticular mesh structure 300 is not an object of the present invention. What matters, as already mentioned, is that it is a structure suitable for working in tension, and that the reticular texture does not clearly separate the lower layers of soil (on which the structure rests) from the upper layers of flooring, so that the its interposition between various layers of the road does not significantly alter the cohesion between these layers, compared to roads built without the presence of this reticular mesh structure 300. Lastly, let us not forget that one of the most important functions of this reticular structure is to provide firm hooks suitable for reinforcing the installation of the "guardrail" uprights on the ground.

It is also of interest to highlight the fact that, in interesting embodiments, the reticular mesh structure 300 is expected to extend well beyond the area where the "guardrails" are normally fixed, or where poles are positioned to support signs or other devices. This prerogative is particularly interesting in the case of raised roads, because by covering the external and typically very sloping wall of the embankments, possibly up to their base, the containment of the soil, which, over time, could erode or collapse is thus facilitated. Ultimately, a number of different interventions aimed at consolidating the embankments in general may result to be facilitated.

Concluding Remarks

In general, as seen from the previous description, the "road system", built according to the teachings of the present invention lends itself to numerous implementation variants.

The description provided already highlights many of these variants In fact, the possible shapes for realizing the hooking points 310 and 320 are innumerable, just as structures with very various geometries and textures can be implemented; and even the size and the partition of the pieces with which the structure is made and laid can be conceived in many ways.

In fact, the inventive activity, in the case of the present invention, has been lavished to conceive a technique for creating a "road system" in which parts that have historically been conceived in a substantially autonomous way collaborate synergistically in the creation of a safe "road system". You are not mistaken if you say that the techniques for preparing the soil of road surfaces represent technologies studied in their own right, just like asphalt and guardrails. The element proposed in the present invention, and indicated as a reticular mesh structure300, connects all these techniques (preparation of the base, asphalting and roadside installations), and, in addition, it also focuses a lot of attention on the roadsides, often implicitly neglected in the construction of roads, but which are still part of the "road system" and also have a great importance in terms of safety.

This reticular mesh structure 300 physically connects all the other elements of the road (in the sense that it is in contact with everyone), but above all, it transfers the technical effects of each part of the "road system" also to all the other elements, creating a synergistic and improving collaboration with respect to the functionality of each individual element: more regular and cohesive road surfaces, and a roadway which offers its great physical contribution, in terms of mass and density, not only to supporting loads on the road, but also to the tightness of the safety barriers and to the consistency of the roadside

The reticular mesh structure 300 indicated in the present invention can be made starting from existing products originally designed only to reinforce the cohesion and resistance of the road surfaces, and making some modifications: in particular by providing a dimension that makes it protrude on the sides of the road, and providing it with reinforced attachment points, suitable for firmly attaching other generic elements of the "road system". Among these further elements of the "road system", for example, we mention the uprights of the guardrails, or poles to support signs or other technological systems (cameras, sensors, etc.), or still other generic elements of the "road system" understood in the widest sense, the presence of which, near roadsides, may be generally advisable.

The fact of using products already designed to reinforce road surfaces allows you to benefit from all the studies already conducted for the purpose and, above all, allows you to be sure that the product will not have an undesirable impact on the overall cohesion of the road surface and on its adhesion to the roadbed. Moreover, the reticular structure (which generally provides fairly large meshes) allows that the direct contact between the roadbed and the surface take place in an adequate manner, and that the adhesion of the road surface on the underlying layers is substantially similar to that which would take place in the absence of reticular structure.

Ultimately, the "road system" according to the invention is substantially characterized by its construction technique which provides that, before the completion of the laying of said asphalted road surface, above the roadbed, as well as above said roadsides, it is laid a reticular mesh structure made of material with good tensile strength. The teachings of the invention, in fact, find their natural application in the construction of new roads, or in the case of fairly radical renovation works; in which the entire road pavement is renewed.

Other very interesting variants of the invention can be conceived in the context of the modernization of the systems serving the road network.

In fact, the presence of a reticular structure underlying the road surface can also be exploited for other non-structural or mechanical purposes. For example, if the material of which the mesh structure 300 is built were electrically conductive, and with a significant electrical resistance, it could also be used to circulate currents and to heat the asphalt, avoiding freezing, which is, for various reasons, a contraindicated phenomenon. Perhaps by exploiting the energy that can be obtained on site from other plants (e.g., geothermal).

Or, if the material has some properties sensitive to pressure or vibrations, it might be possible to devise monitoring systems of certain interest, both for traffic and road conditions. Or again, this reticular structure could be exploited to integrate other sensors and other technological devices that require connection.

This line of applications obviously pertains to problems different from those faced in the present invention, however these problems could be faced by introducing implementation variants that concern the reticular mesh structure 300, which instead represents the heart of the present invention.

All these innumerable variants can be implemented by the man skilled in the art without thereby departing from the scope of the invention as emerges from the present description and the attached claims, and in addition to being able to offer further advantages with respect to those already mentioned, these variants can give rise to the development of different installation methods. Other areas of improvement, in fact, may therefore concern the presence of additional accessory elements, or expedients, which favor installation efficiency.

The invention is therefore susceptible to further evolutionary efforts, capable of improving both the performance of the described system and the installation and/or maintenance procedures. Such developments, if not included in the present description, may be the subject of further patent applications associated with the present invention.

Claims

1. A "road system" including a road substrate (200, 201), the asphalted road surface (210), a roadside (220) not covered by asphalt, and at least one portion of safety barrier (100) installed on said roadside (220); said "road system" being characterized in that it also includes a reticular mesh structure (300) made up of material with good tensile strength, and suitable to be interposed under said asphalted road surface (210), and above the road substrate (200, 201), as well as above said roadside (220), and being this reticular mesh structure (300) designed to cover the road substrate from side to side in its width, and to protrude beyond the area in which the asphalted road surface is to be laid (210); furthermore, said reticular mesh structure (300), in the areas which, after installation, emerge above said roadside (220), has road-edge coupling points (310) which are arranged in a row, at alternating distances or parallel to the asphalted edge of the roadway, and in its immediate vicinity, as said road-edge coupling points (310) are designed to facilitate the firm attachment of other elements of the "road system".

2. "Road system" according to claim 1 , wherein at least some of said road-edge coupling points (310) make a coupling with some uprights 110 of said safety barrier (100), this being installed on said roadside (220) by driving the uprights in the ground.

3. "Road system" according to claim 1, wherein said reticular mesh structure (300) covers also abundantly said roadside (220), projecting significantly beyond the area covered by said road surface (210), and it has additional mesh-edge attachment points (320) positioned on the outermost edges of said reticular mesh structure (300), and said further mesh-edge attachment points (320) are designed to add further ground covering elements attached to them , in order to further extend the covered terrain area, well outside the paved road. "Road system" according to claim 1, wherein said reticular mesh structure (300) covers abundantly also said roadside (220), projecting significantly beyond the area covered by said road surface (210), and it has additional mesh-edge attachment points (320) positioned on the outermost edges of said reticular mesh structure (300), and said further mesh-edge attachment points (320) are designed to apply ground fixing elements of said reticular mesh structure (300). "Road system" according to claim 1 , in which said reticular mesh structure (300) is not rigid, so as it can also be supplied in the form of rolls. "Road system" according to claim 1 , wherein said reticular mesh structure (300) is laid under the part of the road surface (210) which is removed by milling when the road is resurfaced for maintenance purposes. "Road system" according to claim 1 , wherein said reticular mesh structure (300) is made up of more than one reticular mesh, said reticular meshes being laid at different depth levels.