FR2960568A1 - Mold for realizing concrete flooring to make concrete slabs or platforms for public transport, has hollow studs formed of biodegradable polymeric material such that studs are degraded when studs are in contact with water - Google Patents

Abstract

The mold (M) has a flat base (1) arranged with hollow studs (2), where open bases of the hollow studs are inter-connected to the flat base. The hollow studs comprise closed upper ends (20). The hollow studs are formed of biodegradable polymeric material, so that the hollow studs are degraded when the hollow studs are in contact with water. The flat base is made of molded recycled cellulose. Thickness of the upper ends is lower than thickness of side walls of the studs that are connected with each other. Independent claims are also included for the following: (1) a device for realizing a concrete flooring (2) a method for realizing a concrete flooring.

Description

The invention concerns a technical field of the invention.

The invention relates to a formwork mold for the realization of paving hollow concrete. It also relates to a method for producing concrete pavement using such a mold.

The invention relates to the general technical field of construction or floor coverings. It relates more particularly to devices for making concrete pavements on movable ground pads for light or heavy traffic or public transport platforms (trains, trams, etc.). State of the art Known modules of plastic material to assemble, whose reservations can be chosen filled with paving stones, plants or even gravel to form porous media particularly for the realization of vehicle parking areas or green spaces punctually can be driven by intervention vehicles (fire brigade, gas, etc.). This type of embodiment is however unstable and sensitive, in the long term, punching or repeated passages of the wheels of vehicles. 2960568 -2

On the other hand there are non-contiguous decorative paving systems for which the space between the concrete projections can be filled with turf. These paving systems are generally intended for the realization of green spaces and are not circulable. Also known from US Pat. No. 3,802,790 (BLACKBURN) is a formwork mold having a planar base on which are hollow metal, fiber or plastic studs and whose open base is interconnected to said flat base. The pads have their upper end closed. The molds can be placed on a soil containing seeds. The upper ends of the pads are directed upwards, so that the seeds can grow in the interior volume of said pads. Concrete is poured on the mold so as to fill the spaces between the pads, while leaving free their upper end. After germination, the upper ends of the pads are removed either by natural disintegration, by drilling or cutting, or by chemical dissolution or by burning. Grass can grow freely and out of the blocks to form a concrete slab interspersed with plant areas.

In practice, the removal of the upper ends of the pads described in the BLACKBURN patent has many disadvantages. Indeed, a natural disintegration of the constituent material of the pads can take several weeks, or even several months, which can significantly delay the end of a project. Drilling, cutting or burning requires the use of suitable machines which can be expensive and potentially dangerous to handle. A chemical dissolution is likely to cause irreversible damage to the seeds contained in the interior volume of the studs, not to mention the risks of soil pollution. 2960568 -3

In view of this state of affairs, the main objective of the invention is to propose a mold of the type described in the BLACKBURN patent, but which is easier to use and more efficient.

Another object of the invention is to provide a form mold of simple design, inexpensive and whose use is beneficial for seeds and reported soil in which they are installed and which facilitates the recycling of concrete at the end of life of the work realized with this process.

10 Disclosure of the invention. The solution proposed by the invention is a formwork mold for producing concrete pavement, comprising a flat base on which hollow studs whose open base is interconnected with said flat base are disposed, said studs having their upper end closed. . This mold is remarkable in that at least the pads are made of a biodegradable polymer material capable of degrading when in contact with water. The removal of the upper ends of the pads is therefore extremely rapid, without having to use specific tools. Indeed, just pass a simple jet of water under pressure on the upper end of the pads to release their internal volume.

In a preferred manner, the pads and optionally the planar base are made of molded recycled cellulose. This material has many advantages, including that of constituting a reserve of assimilable organic matter for the plants possibly set up in the interior volumes of the pads. It is also a material that is easily degradable by simple contact with water, for example in a natural manner as a result of bad weather. 2960568 -4

To facilitate the removal of the upper ends of the pads, their thickness may be smaller than the thickness of the side walls of said pads and / or may include smaller break zones.

The studs are advantageously interconnected by grooves allowing the passage of conduits for the establishment of a sprinkler system or irrigation and / or for the passage of sleeves containing electrical cables.

Drainage orifices may be made on the flat base so as to allow the evacuation of water collected by the mold before pouring the concrete.

The side walls of the studs and / or the flat base may comprise projecting elements on which are able to rest reinforcing elements arranged between said studs. This reinforces the pavement when pouring concrete.

Another aspect of the invention relates to a formwork device for the realization of concrete pavement, formed of several molds according to the invention, said molds being juxtaposed next to each other. Preferably, grooves opening into the inner volume of the pads are formed at the base of said pads. These grooves are configured to form connecting members for juxtaposing molds side-by-side. After pouring the concrete, a monolithic assembly similar to a real concrete slab is obtained and in which the distribution of loads in the pavement due to the loads is improved.

Yet another aspect of the invention relates to a method for making concrete pavement, comprising the following steps:

- Have on a suitable support one or more juxtaposed molds according to the invention, the upper ends of the pads being directed upwards, - pour concrete on the mold or molds so as to fill the spaces between the pads, while leaving free the upper ends of said pads, - degrade the upper ends of the pads by putting them in contact with pressurized water so as to release the inner volumes of said pads, - fill the inner volumes of the pads with a filling material.

Before casting the concrete on the mold or molds, one can use a protective plate configured to cover the upper ends of the pads while leaving the gaps between said pads. The use of such a protection plate not only protects the upper ends of the pads but also facilitate the filling of the spaces between said pads.

Description of the figures.

Other advantages and characteristics of the invention will appear better on reading the description of a preferred embodiment which follows, with reference to the accompanying drawings, made by way of indicative and non-limiting examples and in which: FIG. 1 is a view from below of a mold according to the invention; FIG. 2 is a sectional view along AA of the mold of FIG. 1; FIG. 3 shows schematically the juxtaposition of two molds according to FIG. FIGS. 4a to 4f schematize the various stages for the manufacture of a concrete slab with filling spaces with a material, 2960568 -6

- Figure 5 is a sectional view of a protection plate for covering the upper ends of the pads.

Embodiments of the invention Referring to Figures 1 and 2, the mold M comprises a planar base 1 on which are arranged hollow studs 2 or cells. These have a conical shape flared towards their base. However, a cylindrical shape could be provided. Their section can be circular, oval, lobed, square, rectangular, polygonal, etc. The studs 2 have substantially the same shape and the same dimensions and are evenly or not distributed on the base 2. One can for example make a flat rectangular base 1 of about 80 cm x 60 cm and supporting three parallel rows of four studs 2 15 regularly spaced. In practice, the pads 2 have a depth ranging from 5 cm to 50 cm, preferably a depth of about 15 cm. The internal diameter of a stud 2 can reach about 15 cm to 30 cm at the base and about 10 cm to 25 cm at the upper end 20. After pouring the concrete, the full / empty ratio is The order of 1. The base of the studs 2 is open and interconnects with the flat base 1 while their upper end 20 is closed. This gives a mold whose shape could be similar to half a box of eggs. The upper ends 20 are intended to be removed in order to leave free the inner volumes 200 of the pads 2 as is explained in more detail in the following description. The thickness of the upper ends 20 may therefore be smaller than the side walls of the studs 2 and / or have areas of ruptures of lesser thickness.

According to the invention, at least the studs 2 are made of a biodegradable polymer material capable of degrading when it is in contact with the material 2960568 -7

of water. The flat base 1 may be made of another material but it is preferred to use a material identical to that of the pads 2. By "biodegradable" is meant, for example, polymers that satisfy the tests specified in the standard EN 13432: 2000. The material used is preferably a natural polymer or biopolymer of the family of polysaccharides such as cellulose, starch, lignin or chitosan. Another family of polymers that can be advantageously used are proteins derived from oleaginous plants, protein crops, cereal bran or animal tissues such as collagen and gelatin. To enhance the mechanical properties of the molds, it is also possible to use synthetic polymers combining biopolymers and traditional polymers of petrochemical origin, such as polyethylene. The biopolymers (about 90% to 99%) constitute the matrix of the assembly, with the traditional polymers (about 1% to 10%) being dispersed within the structure. Pro-degradants, or catalysts, can be added to the polymers to accelerate the breakage of the carbon chains in the presence of water. Conversely, the hydrophobicity of the cellulose can be enhanced by introducing into the cellulose pulp, a neutral and non-toxic environmental sizing agent, in order to obtain adequate mechanical and physical properties.

It is preferred to use molded recycled cellulose which is a by-product of recycling newspapers, papers and / or cartons. The mold is obtained by treatment and shaping recycled cellulose, pressed between two templates. Such a mold has sufficient rigidity to withstand the phases of setting up and pouring the concrete until it is set. The mold has sufficient physical stability to withstand a limited amount of precipitation without degradation. For this reason, drainage holes 10 are 2960568 -8

advantageously made on the flat base 1 so as to allow the evacuation of water collected by the mold before pouring concrete. Recycled cellulose, apart from its low cost and low weight, has the advantage of being degraded after a few months by natural biological processes, once the concrete has completely hardened. In fact, at the end of the life of the structure, the recycling of concrete is facilitated. Cellulose mainly constitutes a reserve of assimilable organic matter for the plants possibly placed in the internal volume of the pads after removal of their upper end 20. Finally, it is a material easily degradable by a simple contact with water, for example in a natural way as a result of bad weather. To quickly remove the upper ends 20 of the pads 2, simply pass a simple jet of water under pressure. Depending on the thicknesses of the upper ends 20 can be used a simple hose 15 spraying generating a pressure of a few bars (for small thicknesses of about 1 mm) or preferably a booster type Karcher® generating a high pressure of several tens of bars (for greater speed or for higher thicknesses, for example about 5 mm).

The thickness of the studs 2 is chosen as a function of the biodegradable polymer material used, so as to have sufficient rigidity to withstand the phases of setting up and pouring the concrete until it is set. For example, with recycled cellulose, the thickness of the pads 2 is between 1 mm and 5 mm. For this last thickness, the mechanical strength of the pads is such that they can withstand the passage of pedestrians before pouring concrete. However, care will be taken to use devices to best distribute these constraints, for example boards or a provisional floor plan.

With reference to FIGS. 1, 2 and 4b, the studs 2 are interconnected by grooves 22 allowing the passage of conduits 220 and in particular ducts, sheaths, tubings, and preferably pipes and the like 2960568 -9

pipes for the implementation of a sprinkler system integrated in the pavement and allowing the emergence of a nozzle or retractable spray nozzle within a pad. This sprinkler system makes it possible, for example, to irrigate the plants whose roots grow in the interior volumes 200. A suction or irrigation system may also be provided for evacuating the trickling water on the concrete pavement and collected. in the interior volumes 200. And even in the absence of conduits 220, the grooves 22 provide efficient and homogeneous drainage of the pads 2. In practice, the grooves 22 are formed at the base of the pads 2 and are molded in the flat base 1, 10 projecting about 25 mm from the upper face of the latter and open into the inner volumes 200.

Referring to Figure 1, to strengthen the concrete floor, can be integrated between the pads 2 reinforcing elements 3 (shown in dashed lines), the welded wire mesh type whose meshes respect the frame formed by the pads 2 , steels for longrins, expansion joints, etc. The reinforcement 3 aims to take over or minimize the tensile forces and shear forces of concrete. To ensure ideal positioning of these reinforcing elements 3, the side walls of the studs and / or the flat base 1 20 may comprise projecting elements on which are able to rest said reinforcing elements. In practice, the projecting elements are formed by the grooves 22. However, other dedicated elements independent of the grooves 22 could be provided, for example of the type of concrete reinforcing wedges. Depending on the surface of the pavement to be made, several molds can be easily juxtaposed next to one another. In order to ensure easy assembly of the molds, the grooves 22 are configured to form connecting members for juxtaposing side-by-side molds. Referring to Figure 3, it is sufficient to fit the grooves 22a located on the sides of a first mold M1 in the adjacent grooves 22b located 2960568 -10-

on the sides of a second mold M2, the arcuate shape of said grooves allowing this interlocking. The juxtaposition of the molds and the straightness of the alignments is then guaranteed by this original clipping system.

The various steps for making the concrete pavement will now be described in more detail with reference to Figures 4a to 4f. The initial step (Figure 4a) is to arrange on a suitable support S, one or more molds M juxtaposed. The support S is preferably flat and consists, in practice, of the earth. It is prepared by a terracing of the ground to be paved. The molds M are positioned on the support S so that the upper ends 20 of the pads 2 are directed upwards. The interior volumes 200 are opposite the support S. If the embodiment comprises the integration of a sprinkler or irrigation system, the ducts 220 are conveyed into the grooves 22 and placed in the interior volumes 200 ( Figure 4b). It is also possible to set up during this step the reinforcing elements 3 between the pads 2. It may be advantageous to use a protection plate P configured so as to cover the upper ends 20 of the pads 2 while leaving free the spaces between said pads. In practice, a sheet of some 20 millimeters thick is used, in one or more parts depending on the dimensions of the mold. With particular reference to FIG. 5, this plate P comprises perforations A which release the spaces between the studs 2. These perforations A facilitate the filling of the spaces between the studs 2 while protecting their upper end 20. The casting concrete B on the molds M (Figure 4c) is made to fill the spaces between the pads 2, while leaving free the upper ends 20 of said pads. The casting is carried out so as to ensure a good coating of the possible reinforcement elements 3 and 30 conduits 220. The concrete B is set up in a known manner, in the case of the concrete.

state of the art. At the end of this step, if the plate P has been used, it can be removed. In the transitional phase of construction (Figure 4d), as soon as the hardened concrete B has reached the mechanical strengths in bending and / or traction prescribed, the pavement 5 is movable. The filling of the pads 2 can be performed later. In fact, a monolithic system is obtained, analogous to a real concrete slab. The upper ends 20 of the pads 2 are then degraded by putting them in contact with water under pressure, so as to release the internal volume 200 of said pads (FIG. 4e). Depending on the nature of the material used for making the molds, a simple passage to the water jet, possibly combined with a mechanical punching or scraping action, is sufficient to remove the upper ends 20. For more efficiency and rapidity, the surface of the pavement is cleaned by means of a water booster 15 of the Karcher® type. The inner volumes 200 are then filled with a desired filling material R (FIG. 4f). It may be granular material such as gravel, resin concrete, topsoil (eg from excavation), seed or turf, any other porous or draining media, or a combination thereof. .

Claims (12)

REVENDICATIONS1. Form mold for the realization of concrete pavement, comprising a flat base (1) on which are arranged hollow studs (2) whose open base is interconnected to said flat base, said studs having their upper end (20) closed, characterized in that at least the pads (2) are made of a biodegradable polymer material capable of degrading when in contact with water. 2. Mold according to claim 1, wherein the pads (2) are made of molded recycled cellulose. 3. Mold according to one of the preceding claims, wherein the plane base (1) is made of molded recycled cellulose. 4. Mold according to one of the preceding claims, wherein the thickness of the upper ends (20) is smaller than the thickness of the side walls of the studs (2) and / or has areas of smaller ruptures 5. Mold according to one of the preceding claims, wherein the pads (2) are interconnected by grooves (22) for the passage of ducts (220). 6. Mold according to one of the preceding claims, wherein drainage holes (10) are formed on the flat base (1). 30 2960568 -13- 7. Mold according to one of the preceding claims, wherein the side walls of the studs (2) and / or the flat base (1) comprise projecting elements on which are able to rest reinforcing elements (3) arranged between said pads. 8. Formwork device for the realization of concrete pavement, characterized in that it is formed of several molds according to claim 1, said molds being juxtaposed next to each other. 10 9. Device according to claim 8, wherein: - grooves (22) opening into the inner volume (200) of the pads (2) are formed at the base of said pads, - the grooves (22) are configured to form assembly elements for juxtaposing molds side by side. 15 10. A method for producing concrete pavement, comprising the following steps: - placing on a support (S) adapted one or more molds (M) juxtaposed according to claim 1, the upper ends (20) 20 of the pads (2). ) being directed upwards, - pouring concrete (B) on the mold or molds (M) so as to fill the spaces between the studs (2), while leaving free the upper ends (20) of said studs, - degrade the upper ends (20) of the pads (2) by putting them in contact with water under pressure so as to release the inner volumes (200) of said pads, - filling the interior volumes (200) of the pads (2) with a filling material (R). 30 11. A method according to claim 10, wherein before pouring the concrete (B) onto the mold (s) (M), a protection plate (P) configured to cover the upper ends ( 20) pads (2) while leaving free the spaces between said pads. 12. Method according to one of claims 10 or 11, of using molds having pads (2) made of molded recycled cellulose.