The invention relates to a noise barrier, more exactly to a noise protection wall, comprising ba- sically vertical support elements fixed to the ground, wall elements inserted between the sup- port elements, where the wall elements comprising a support layer providing mechanical strength and a noise dampening layer connected to it.

The growth of road traffic, not least the increasing mass and performance of vehicles, which increase traffic noise, at the same time the tightening of environmental protection require- ments and regulations make it necessary in more and more places to install noise protection walls, primarily near populated areas, along the roads to reduce the noise caused by traffic.

CH 671054 A5 discloses a wall panel for a noise protection wall. As a main supporting compo- nent of the wall panel, there is a reinforced concrete support plate that forms a back wall, on the front side of which, i.e., the side of the roadway facing traffic, layers of lightweight con- crete that are not self-supporting are arranged on top of each other, where the outermost layer has a toothed design to ensure good noise absorption.

DE3727947 C2 describes a basically similar noise-damping and noise-dampening building ele- ment, in which cover plates provided with noise-dampening recesses and projections are ar- ranged on an ordinary support plate made of concrete. According to the document, these cover plates can be made of rock wool, glass wool, foamed plastic or similar materials, whose sound-absorbing and noise-reducing properties are well known, but their production and use cannot be considered environmentally friendly.

US7,220,077 B2 describes a safety noise protection system that can be installed along a traffic route, essentially including fence boards and posts supporting them, constructed from materi- als traditionally used for noise reduction. Although the structure of this solution can contribute to noise reduction and to the reduction of injuries in the event of possible traffic accidents, its structure is complex and expensive, and its production is material- and labour-consuming.

US8,307,950 B1 proposes a solution for an active noise reduction element of a noise protec- tion wall. The document describes a monolithic sound-absorbing concrete structural element produced by casting, into which, among other things, wood particles enhancing sound-absorb- ing properties and granulated rubber particles are introduced during production. Also, in this case the noise protection wall basically comprises ordinary concrete wall elements.

To the best of my knowledge, among the many wall elements produced in different ways that can be used for noise protection, there is no wall element that, in addition to having good noise-damping and sound-absorbing properties, can be produced more advantageously, more usefully, and less harmful to the environment than before, considering that more and more noise protection walls are needed.

The invention is based on the realization that the state-of-the-art glass foam produced with known technologies from glass waste, which is becoming a growing problem worldwide with- out proper recycling, could, due to its structure and physical properties, be advantageously used in a wall element of noise protection walls with appropriate mechanical design.

The objective has been solved with a noise barrier according to claim 1 , which can be used for noise protection walls and is produced in an environmentally f riendly way. Some of the noise barrier designs that are considered advantageous are listed in dependent claims.

One embodiment of the invention is described exemplarily with reference to accompanying drawings corresponding to the embodiment. The exemplary description does not constitute any limitation on the embodiments. Components marked with the same reference numeral in the accompanying drawings represent similar components. Unless otherwise specified, the ac- companying drawings do not constitute any scale limitation.

Fig. 1 is a perspective view of a possible embodiment of a wall element in the state of being installed in a noise barrier according to the invention.

Figure 2 shows a horizontal section of the wall element according to Figure 1 .

Figure 3 shows in the vertical section of a noise barrier the fastening of a wall element to the support posts.

Figure 4 shows the detail IV of Figure 2 in an enlarged view.

Figure 5 shows the detail V of Figure 2 in an enlarged view.

A noise barrier 1 shown schematically in Figure 1 as a preferred example is normally assembled of wall elements 3 arranged between vertical support posts 2 fixed into the ground, and of plinth elements 4 supporting them. The assembly functioning as a blade wall is statically di- mensioned as a simply-supported beam. In the horizontal cross-section along a line A-A shown in Figure 2, it can be seen that a wall element 3 is composed of a support layer 5 correspond- ing to the support plates of the known solutions and, in this example, a single noise-dampen- ing layer 6, which, when assembled, is slid into the two previously installed support posts 2 of “I” cross-section in the installation position from above , and the wall elements 3 are held by these support posts 2 against twisting and tipping. The noise-dampening layer 6 is arranged on the outer side of the wall element 3, facing the road, and in the embodiment presented it has a vertically wavy design. In the vertical cross-section along a line B-B shown in Figure 3, it can be seen that the wall element 3, and its primarily load-bearing support layer 5, rests on the plinth element 4 that supports the wall element 3 from below. In Figure 2, sleeves 7 necessary for wedging the supporting layers 5 of the wall elements 3 in their final position to the support posts 2 from the back, lifting plugs 8 inserted into the supporting elements 5 to facilitate the movement and lifting of the wall elements 3, as well as a grounding wire 9 being in galvanic connection with a reinforcing insert of the supporting layers 5 are symbolically indicated. The vertical edges of the support layer 5 are rounded to facilitate sliding into the support posts 2. Fig. 3 also shows a seal 10 arranged between the wall element 3 and the plinth element 4, fur- ther in the wall element 3 at the junction of the support layer 5 and the noise-dampening layer 6, formed advantageously and also in the present example by a rubber band.

In the example shown, the support posts are HEA/ HEEA galvanized steel beams chosen accord- ing to the dimensions of the noise barrier 1 and the wall element 3. For the size of the 3 wall elements, its length is determined by the distance between the two support posts 2 with a necessary abbreviation of 1 -3 cm for the installation, and its height depends on the desired noise reduction and mechanical limits, for example expected wind load.

The plinth elements 4 and the support layer 5 made of reinforced concrete are produced using known and suitable technology according to the dimensions to be produced. The height of the plinth elements 4 can be no more than 1 m in the case of a 5 m high noise barrier, depending on the current terrain conditions.

The material of the 6 noise-dampening layers comprises expanded glass foam, in the embodi- ment shown a product “ PORAVER” produced by Dennert Poraver GmbH, Germany. The noise- dampening layer 6 is prepared using a following recipe:

Concrete: 250 kg/ m ³ PORAVER: 205 kg/ m ³ Water: 113 l/ m ³

Air-pore forming agent “Ska LPSA” : 1 .5 kg/m ³ , 0.5% of concrete quantity.

In Figure 4 the exemplary design and dimensions of the support layer 5 and the noise-dampen- ing layer 6 can be shown in more detail. A thickness h _t of the support layer 5 is 100 mm, a total thickness h _z of the noise-dampening layer 6 is 140 mm, of which a thickness h _z1 of a back layer of the noise-dampening layer 6 being in connection with the support layer 5 is 55 mm and the thickness of a corrugated layer h _z2 integrated with it is 85 mm. The waves of the corrugated layer are rounded on the outside with a radius R _h and on the inside with a radius Rv, a length t _h of a straight section connecting the roundings and forming an angle a=74° to the plane of the support Iayer 5 is 50.7 mm, so the symmetrically formed wave crest -valley-wave crest dis- tances t _a , t _b are 62.5 mm.

In the detail of Figure 5, an exemplary placement and fixing of the wall elements 3 in the sup- port posts 2 can be shown in more detail. The wall element 3, or more precisely an outermost region of the support layer 5, is clamped to a steel plate extension of the support post 2 of “I” cross-section by a hex head screw 11 screwed into a sleeve 7of a threaded wedge. An other end of the grounding wire 9 grounding the wall element 3, which, when used, must be con- nected to a proper element of the noise barrier 1 serving as grounding, for example to the sup- port post 2, is connected to the wall element 3 with a screw 13 that can be screwed into a threaded grounding sleeve 12 formed in the support layer 5 and galvanically connected to its reinforcement, as usual in the field, via spring or toothed washers 14. Fixing the wall elements 3 after their inserting in the corresponding support posts 3 will be made by unscrewing the screws 11 of the size M 10-M 12, previously fully screwed into the sleeves 7, and tightening said screws 11 with a spanner on the back side of the support layer 5.

Depending on the production technology, the wall element 3 can be produced in one or two stages, in the former case the supporting layer 5 made of steel concrete and serving as the background supporting structure is applied to the fresh noise-dampening layer 6 made of glass foam before its solidification, or in the latter case the supporting layer 5 made of steel con- crete and serving as the background supporting structure is applied to the noise-dampening layer 6 made of glass foam after it has solidified. As a third option, e.g., during renovation or replacement, the noise-dampening layer 6 can be installed on the support layer 5 by gluing and fixing with dowels.

The production process typically takes place in a production hall equipped with cranes, lying on shaking tables. Steps of an exemplary production, known to a person skilled in the art are:

- pre-production of iron fittings;

- cleaning the steel template, placing it and fixing it with magnets on the shaking table;

- spraying formwork with mold release oil;

- the formwork system is designed in such away that it forms the negative (wave insert) of the noise-shielding surface;

- inserting the reinforcing armature in a steel template, using suitable plastic spacers; - fastening of fittings in the template: sleeves 7 of lifting dowels 8 and wedging screws 11 ;

- concrete casting in one or two mentioned phases, depending on whether the noise-dampen- ing layer 6 with the steel concrete 5 support layer is carried out in one or two separate work phases, this depends on the production technology, the equipment and design of the produc- tion hall;

- compacting the concrete with the help of a rod vibrator and/or a shaking table;

- screeding the upper concrete surface - according to the installation position, this will be the backside surface - smoothing by hand, or preparing a hand-swept surface according to cus- tomer’s request;

- after a suitable solidification time, formwork and factory storage of the elements;

- storage of elements on site in transport boxes, or stacked one on top of the other, until deliv- ery;

- cleaning the formwork then repeating the above processes.

Among the advantages of the noise barrier according to the invention excellent noise-dumping and noise-dampening properties, high efficiency in air sound insulation can be mentioned. The noise barrier is visually attractive, pleasing to the eye, has a harmonious appearance, unique size and shape, it can be up to 20-25% lighter in its category as the state-of-the-art concrete noise barriers, is weatherproof and maintenance-free and can be installed quickly.

List of reference signs:

1 noise barrier

2 support post

3 wall element

4 plinth element

5 support layer

6 noise-dampening layer

7 sleeve

8 lifting dowel

9 ground wire

10 seal

11 screw

12 grounding sleeve 13 screw

14 washer h _t thickness h _z thickness h _z1 thickness h _z2 thickness

_R h, R _v (rounding) radius t _h length t _a distance t _b distance α angle