SOUND-DAMPING SCREEN COVERED WITH GROWTH, COMPRISING PANELS COVERED WITH PLANTS AND A SUPPORT CONSTRUCTION
The invention relates to a sound-damping screen covered with plants for disposing along for instance motorways, railway lines or airports. The screen is constructed from a support construction which is lined on one or two sides with panels covered with plants.
Traffic noise is one of the most important disruptive environmental factors impacting people in residential areas in the vicinity of intensive traffic. In order to prevent the full volume of noise from traffic being able to reach a residential area to be protected, noise-limiting constructions are arranged. Plants arranged on or against these constructions mitigate their artificial nature, and make a positive contribution toward acceptance by people living in the neighbourhood and road users.
Sound-damping screens covered with growth are known in many forms and assemblies. First are the earth embankments, sometimes filled with waste products such as old tyres filled with compost and the like (DE 3734411 Al; DE 4443478 Al) . When little space is available for an earth embankment, or a relatively high embankment is required, use is then made of planted, stacked constructions of for instance concrete (EP 0452744 Al; EP 1312718 A2) or recycled plastics (DE 4212093 Al) . In the case of even greater height-width ratios vertical walls are employed, against which greenery is placed. The core of such a wall often consists of one or more layers of sound-absorbing plates (NL 8801579; WO 99/22075) . The efficiency of installation can be increased by giving the vertical wall a modular construction (WO 02/48463) .
Despite the many options there occur problems in existing green sound-limiting constructions which are mainly associated with the vitality of the plants and/or the frequently high management costs. Vitality of the plants greatly depends on the amount of precipitation.
In dry periods a shortage of moisture will soon occur, while excess water can result in acidification of the substrate in which planting takes place. Stacked constructions in particular are highly susceptible to this. The maintenance of planted screens often entails high costs for replacement of the plants, pruning and clearing. Research under extreme conditions has demonstrated that said drawbacks will occur to much lesser extent if screens were planted with varieties of sedum. A condition here is that the screen is not placed vertically but at least 1OD out of the vertical. In the case of screens with growth on two sides two walls are necessary which are placed against each other with an enclosed apex angle of at least 2OD. In order to create an environment suitable for sedum under these practically vertical conditions, modifications are necessary -in the construction of the planted screen, and these are provided by this invention.
The object of the invention is to now realize a practically vertical sound-damping screen to be covered with plants on one or two sides, on which screen optimal growth conditions are possible for, among others, sedum varieties . The screen must provide efficient protection from normally occurring traffic noise and be constructed from elements which can be manufactured industrially and are easy to transport. This at minimal cost for the purpose of a) cultivating the plant material, b) the construction and installation of the screen structure, and c) maintenance of plants and screen.
This object is achieved, in contrast to the method in existing green vertical sound-damping screens, by no longer arranging the plants on site but by making use of cultivation and planting-out at nurseries under the optimum conditions for the variety of plant and in a substrate specific to this plant. The consequence of this choice is that proper logistics have to be developed for cultivation, harvesting, transport, arranging on the screen, maintenance and replacement of plants. For the cultivation of pot plants product
carriers such as for instance plastic cases are in use. Placing of these existing product carriers as a kind of panel on the sound-damping screen results in insufficiently optimal growth conditions for the plants . The product carriers are after all developed for cultivation and transport of pot plants, and no account has been taken of growth conditions under permanent, practically vertical placing on a sound-damping screen. There is therefore a need for a plastic product carrier which is developed specially for green sound-damping screens and which has properties which result in optimum conditions at all process stages and in the installed situation. The invention provides for this need with a product carrier in the form of an assembled plastic tray which is arranged as panel on a support construction in the sound-damping screen. The panel is constructed from at least two parts: a first part filled with a substrate which provides optimum culture conditions for the plants and which is designed such that erosion of the substrate after fitting on the screen is prevented, and a second part which can be connected to the first part, and thus forms a product carrier for transport from the nursery, and which, once fitted as panel on the screen, regulates the moisture provision to the plants by temporary storage and slow release of the precipitation collected by the screen.
The invention will now be elucidated with reference to the accompanying drawings. In the drawings :
Fig. 1 shows the first part of the product carrier. Fig. 2 shows the first part of the product carrier in the first stage of cultivation.
Fig. 3 shows the second part of the product carrier.
Fig. 4 shows a corner support connecting both parts of the product carrier.
Fig. 5 shows a number of stacked product carriers ready for transport to the building location.
Fig. 6 shows the product carrier placed at the angle of inclination of the screen. Fig. 7 shows a first exemplary embodiment of the support construction.
Fig. 8 shows a stack of concrete elements. Fig. 9 shows fixing of the panels to the support construction of Fig. 7.
Fig. 10 shows a second exemplary embodiment of the support construction.
Fig. 11 shows further subdivision of the first part of the product carrier.
Fig. 1 shows the first part of the product carrier. The part designated as a whole with 1 is a container in which a partitioning is arranged on a grid-like bottom 4 by placing ribs 5 on this bottom. The closed sides 6 make it possible to fill this part of the product carrier with a substrate 7 suitable for cultivation of the plants . Ribs 5 provides the container with a compartmentalization which locks the plants in position and, after placing on the sound-damping screen, prevents the substrate and parts of the plants being washed away. Through the partly open bottom the roots of the plants can anchor themselves to the grid-like bottom 4 and are able to continue growing into the second part 2 of the product carrier to be placed under the first part 1. The first stage of the culture can take place in a horticulture greenhouse. Sewing or taking of cuttings can take place here in a good working environment, and optimum growth conditions can be set.
Fig. 2 shows the first part 1 of the product carrier in the first stage of the cultivation under glass. Once the crop is sufficiently rooted, the cultivation can be continued in the open air. Because growth conditions in the outside air are less readily controllable, at this stage of the culture the amount of substrate available for continued root growth can be increased by coupling the first part of the product carrier to the second part. This coupling can also be postponed until a later stage of the culture, or even until the moment of fitting on the screen.
Fig. 3 shows the second part 2 of the product carrier. This part also has the form of a container. The bottom 8 is however for the most part closed. A partitioning is arranged on this bottom by placing ribs 9. Each bottom compartment is provided with a drainage
opening 10. In the shown exemplary embodiment of part 2, ribs 9 provide a compartmentalization of the bottom into a hundred compartments, while the compartmentalization in the first part has four hundred compartments. Four compartments filled with plants are placed above each compartment in part 2 when this latter is joined together with part 1. The compartments of part 2 are filled with a substrate 11 having a large water buffering capacity. Examples of substrates suitable for this purpose are Grodan® rockwool or Bims® lava, which can absorb 50-60% by volume of water.
Fig. 4 shows a corner support designated as a whole with 3 which is fastened by means of snap elements 12 onto part 2 of the product carrier. The ribs 13 arranged on the corner supports clamp the parts 1 and 2 of the product carrier onto each other. With a view to the coupling of parts 1 and 2 it is possible in the second stage of the cultivation to opt to allow continued growth of the plant roots into substrate 11 with which part 2 is filled. In respect of ready handling, the total weight of product carrier, moist substrates and plants must remain below 25 kg per product carrier. Main dimensions of the product carrier are therefore set in this exemplary embodiment at 60 x 60 cm, this however without precluding other suitable main dimensions .
At the end of the cultivation the product carriers are made ready for transport. Fig. 5 shows that the product carriers are stackable on corner supports 3 which couple parts 1 and 2 of the product carrier. There is enough space between the stacked product carriers that the crop is damaged as little as possible during stacking and transport.
In Fig. 6 the product carrier is drawn in the position occupied after mounting on the support construction of the sound-damping screen. The function of parts 1 and 2 of the product carrier becomes apparent in this practically vertical position. Part 1 has the arrangement with small compartments so as to hold fast the plants and substrate 7 under extreme weather conditions such as heavy rainfall and storm. Part 2 regulates the moisture management. As much moisture as
possible is held in the water-buffering substrate 11, while excess moisture can still flow away via the drainage openings 10 in the bottom 8 of part 2.
The product carrier constructed from parts 1 and 2 and 3 is mounted as a panel in a support construction and forms together with this construction a sound- damping screen. Two possible exemplary embodiments of a support construction are given.
Fig. 7 shows a stacked concrete support construction consisting of U-shaped gutter elements 14, 15, 16, 17. Elements 14 are placed as first layer on a tamped sand bed at a mutual distance equal to the base width of the U-shaped gutter. The second layer consists of less wide elements 15. When the support construction is at the desired height, it can be covered with a semicircular concrete element 18.
In Fig. 8 can be seen how elements 14-17 are positioned relative to each other. At the corners 19 on the base the elements 15 form a connection with the top side 20 of the vertical walls of elements 14.
Displacement in the gutter direction is prevented in that protrusions 21 on element 15 drop into a groove 22 in element 14.
Fig. 9 shows fastening of the planted panels to the concrete support construction of Fig. 7. Fastening to the concrete support construction takes place at the corners 23 of parts 2 of the panels. A fixing plate 24 clamps the corners of four adjoining panels to the support construction using a bolt 24. A plastic plug is accommodated in the relevant concrete element for the purpose of fastening the bolt.
A second exemplary embodiment, a support construction of steel 26, is shown in Fig. 10. The steel construction can be fixed to concrete crossbeams or to a cast concrete foundation 27. Because use is not made for the steel construction of moulds specific to the construction, more possibilities for variation are available per project with this support construction. A support construction of steel will thus require a less wide base compared to a concrete support construction.
In the case of damage to the sound-damping screen covered with growth according to the invention or during partial replacement of plants that have died off, part 1 of the product carrier can be removed and replaced by a carrier cultivated with new plant material. For replacement of the plants on compartments which are smaller than the dimensions of one panel, it is advisable to not manufacture part 1 integrally but to subdivide it into for instance three or six sub-elements which together cover one part 2. Fig. 11 shows a subdivision into three sub-elements 28.