EP0005117A1 - Method of constructing playgrounds and products issuing from it - Google Patents

Abstract

A method of constructing a hard tennis court, in which it is possible to cast in situ a thin concrete slab while permitting recovery of part of the formwork supporting means. It consists in placing formwork panels 5 on a screen of cables 2 arranged transversely to reinforced-concrete longitudinal members 1 and secured at the ends to posts 3. Plumb with each longitudinal member, each cable passes through a tube portion 4; between the tube elements and in the direction of the longitudinal members, the plates 5 rest on wooden strips 6, of thickness corresponding to the diameter of the cables plus a tube thickness; after drying of the slab, the cables and formwork elements can be removed, as well as elements for framing the expansion joints and perforations permitting drainage of rainwater. The invention is applied to the production of any horizontal slabs separated from the ground by a ventilation space, such as tennis courts. <IMAGE>

Description

The present invention relates to a method of building a hard tennis court.

It is increasingly known to replace traditional clay courts with hard courts, allowing among other advantages to be able to practice this sport all year round without the obligation that these courts be covered, to combat the risks of frost. In addition, it was confirmed that these achievements gave a satisfactory rebound quality of the ball. The implementation of the construction methods must make it possible to obtain a perfectly flat platform which, although relatively flexible, must resist the risks of lifting or subsidence. Thus, certain construction methods consist in making a grid of prefabricated parallelepipedal concrete blocks placed on concrete dice poured into the ground and emerging from it, on which are laid reinforced concrete beams in the longitudinal direction. of the court, intended to support reinforced concrete joists arranged in the transverse direction. The whole of this structure receives concrete plates arranged in a contiguous manner, providing the actual playing area, which is suspended a few centimeters above the ground. This arrangement gives it elasticity and flexibility. siréeset avoids any influence of the humidity of the ground or the accumulation of rainwater. However, this construction method has the drawback of requiring significant means of transport as well as essential lifting means on the site, which makes this solution expensive. To remedy this, other techniques consisting in pouring the whole of the on-site structure has been envisaged: given the low height of the structure relative to the ground, we cannot envisage recovering the formwork means.

The construction method according to the invention makes it possible to avoid these drawbacks. In it, it is indeed possible to pour on site a thin concrete slab a few centimeters from the ground, while allowing to recover part of the support means of said slab after drying.

The construction process. object of the invention is to sink a number of reinforced concrete sills or not arranged at regular intervals along the greatest width of the ground, the upper face of said sills being perfectly leveled. Transversely to these sills, are stretched at determined intervals steel ropes clamping the upper faces thereof. These ropes are housed, at the passage of each sill, in a portion of tube, which will then be embedded in the thickness of the slab allowing to recover the said ropes after drying of the slab. On this rope frame are placed wooden or agglomerated sheets of sufficient thickness to avoid any deformation of flatness during the pouring and drying of the slab. The longitudinal edges of these plates rest between the ropes, on wooden battens arranged on the sills and in the same direction as these: their length corresponds to the spacing of the expansion joints of the slab; in the other dimension the spacing of these joints is equivalent to a certain number of plates. The value of the expansion joint is obtained by means of flat bars placed on the field, the upper edge of these bars making it possible to pull the casting platform with the vibrating rule. Cross supports placed at the intersections of the expansion joints keep the flat irons in their position during the casting of the platform, which flat irons are then removed.

The process for constructing thin concrete slabs for the production of platforms located a few centimeters above the ground, and more particularly of platforms used for the practice of sports, such as tennis, is characterized in what it consists of maintaining a non-deformable formwork plane at the desired distance from the ground by means of recoverable supports after the casting and drying of the platform and simultaneously making the expansion joints necessary for the good performance of said platform -form using removable means, which means make it possible to draw the vibrating ruler of the whole of the platform,

According to the invention, the means of supporting the the formwork plane at a certain distance from the ground is a frame of parallel steel ropes stretched transversely to reinforced or unreinforced concrete beams, arranged parallel on the ground in the direction of the width of the structure, which ropes _/ moored at each end to piles driven into the ground outside the structure, clamping their tension on the upper face of the stringers.

The cables pass directly above each sill portion a portion of tube, which is embedded in the concrete slab during the casting of the slab, leaving the possibility of sliding of the rope for its removal after casting.

The non-deformable formwork plan is made up of wooden or agglomerated sheets of sufficient thickness to avoid any deformation of flatness during the casting and drying of the platform, which wooden plates are placed on the weft of the ropes of steel.

Each plate constituting the formwork plane rests by its longitudinal edges on wooden battens placed on beams and in the direction thereof between the tube elements, the thickness of said battens corresponding to the diameter of the rope plus the tube thickness.

Each plate constituting the formwork plane is made up in the width direction, of two lateral bands and of a central band, which bands rest on the frame of the steel ropes, which lateral bands are fixed integrally with the wooden battens placed on the sills and in the direction thereof between the tube elements, which central strip / width less than the spacing of the lonqrines, has its contiguous edges with the side bands in clearance so as to facilitate its fall into the void area located under the slab after the removal of the ropes for recovery.

The plates constituting the formwork plane have, uniformly distributed, frustoconical hollow dowels - with cylindrical base provided with a collar implanted in the thickness of the plates, large base down, the height of the conical part corresponding to l he thickness of the slab, which pegs, embedded in the concrete, allow the evacuation of rainwater towards the vacuum zone existing under the slab.

The recoverable plates constituting the formwork plan comprise, uniformly distributed, solid frustoconical dowels, being implanted in the thickness of the plate and held by nut, in order to produce as many molds as possible for the evacuation of rainwater. towards the existing vacuum zone under the slab,

Rainwater is evacuated by hollow frustoconical dowels glued at regular intervals on a sheet of waterproof felt placed on the formwork plates before pouring the slab.

The slab is squared by lines of orthogonal expansion joints, the spacing of which corresponds to the length and to a multiple of the width of the formwork plates, the width of which expansion joints are determined by the thickness of flat bars arranged on the field. and held at their intersection by cruciform supports allowing their removal after use, the edge of which flat irons corresponding to the planned upper level of the pouring slab thus constituting m reference plane for the drawing with the vibrating rule of the whole of the slab after its casting.

Notches are provided, arranged at regular intervals along the length of the reinforced or unreinforced concrete sills, in which are received steel ropes constituting a frame and serving to support the formwork plane at a distance from the ground, said notches being made of so as to be punched in coincidence with each other, and to allow both easy passage and removal of the ropes.

We carry out the implementation of the notches at the time of the pouring of the concrete stringers,

The notches on the sills have a V shape with a rounded base,

After the implementation of the beams provided with notches receiving the frame of ropes, there is interposed, before the operation of setting up the formwork plane consisting of panels, a sheet metal bearing on the beams whose role is to allow the removal of the ropes after the concrete slab has dried.

The sheet is a light sheet of the strip type, said sheet being embedded in the assembly during the demolding of the concrete slab.

The sheet retains the formwork panels, and provision is made for the installation of nails for fixing said sheet to the beams.

For the positioning of the plates or panels, there are parallel straps leaving a gap between the panels,

After the concrete slab has dried, to remove formwork, the ropes are removed, which causes fall of a line of panels, which are recovered by traction on the straps which connect them,

The straps are stapled to the panels.

The straps, when the panels are brought together, have a recess,

According to an alternative embodiment of the present invention, it has been found that it was possible to practice, at regular intervals on the sleepers, notches intended to receive the ropes, thus avoiding the provision of tubes then embedded in the thickness of the slab .

Likewise, it has been found that the insertion of a light plate retaining the panels, and which is nailed to the sills, constituted an advantageous means of replacing the cleats,

Finally, as another characteristic, it is advisable to indicate the installation of straps stapled to the plates or panels and allowing their removal.

• - en figure 1, une vue en perspective cavalière partielle de la mise en place des panneaux supports sur les câbles tendus transversalement aux longrines,
• - en figure 2, une coupe transversale correspondant à la figure 1,
• - en figure 3, une vue de dessus correspondant à la figure 2,
• - en figure 4, une vue de dessus montrant le détail des fers plats dont l'enlèvement après coulée réalise les joints de dilatation des dalles,
• - en figure 5, une vue en perspective cavalière d'un support cruciforme servant au positionnement des fers plats représentés en figure 4,
• - en figures 6 et 7, le détail en élévation coupe et en vue de dessus du positionnement d'un support cruciforme,
• - en figures 8, 9 et 10, différents types de moyens incorporés au coffrage pour obtenir la perforation de la dalle en vue de l'évacuation des eaux de pluie,
• - en figure 11, une vue de côté,prise dans le sens longitudinal,d'une longrine en béton armé ou non, pourvue d'encoches pour la mise en place de filins d'acier,
• - en figure 12, une vue de détail de la figure 11 montrant mieux la forme de l'encoche,
• - en figure 13, une coupe transversale illustrait la disposition de divers éléments pour la mise en oeuvre du procédé de l'invention,
• - en figure 14, selon une coupe transversale, l'emplacement respectif des éléments constitutifs, notamment des panneaux de coffrage de largeur inférieure à l'écartement des longrines,
• - en figure 15, en perspective, l'association entre les panneaux de coffrage et les sangles destinées à leur retrait après la coulée d'une dalle,
• - en figure 16, la façon selon laquelle les sangles recouvrent les panneaux en vue d'une opération de pliage desdits panneaux,
• - en figure 17, une vue de côté de plusieurs panneaux et des sangles agrafées sur ces panneaux, montrant la creusure des sangles au moment du rapprochement des panneaux

The accompanying drawings illustrate, by way of example, an embodiment of the method according to the present invention. These represent:

• in FIG. 1, a partial perspective view of the positioning of the support panels on the cables stretched transversely to the stringers,
• in FIG. 2, a cross section corresponding to FIG. 1,
• in FIG. 3, a top view corresponding to FIG. 2,
• - in FIG. 4, a top view showing the detail of the flat irons, the removal of which after casting produces the expansion joints of the slabs,
• in FIG. 5, a perspective view of a cruciform support used for positioning the flat bars shown in FIG. 4,
• - in Figures 6 and 7, the detail in sectional elevation and in top view of the positioning of a cruciform support,
• - in FIGS. 8, 9 and 10, different types of means incorporated into the formwork to obtain the perforation of the slab for the evacuation of rainwater,
• - in FIG. 11, a side view, taken in the longitudinal direction, of a reinforced concrete sill or not, provided with notches for the installation of steel cables,
• in FIG. 12, a detailed view of FIG. 11 better showing the shape of the notch,
• in FIG. 13, a cross section illustrates the arrangement of various elements for implementing the method of the invention,
• in FIG. 14, in a cross section, the respective location of the constituent elements, in particular shuttering panels of width less than the spacing of the stringers,
• in FIG. 15, in perspective, the association between the formwork panels and the straps intended for their removal after the casting of a slab,
• - in FIG. 16, the way in which the straps cover the panels for a folding operation of said panels,
• - In Figure 17, a side view of several panels and straps stapled on these panels, showing the recess of the straps when the panels are brought together

The implementation of the method according to the invention consists in pouring, on perfectly leveled ground, sills 1 of length corresponding to the width of the court, spaced about seventy five centimeters, these sills being made of reinforced concrete or not, depending the nature of the land; their upper face must be perfectly level, so as to constitute a reference plane. Crosswise to these sills, steel cables 2 are placed at fixed intervals, each end of the cable being moored to a pile 3 driven into the ground outside the structure; directly above each sill, the rope 2 passes through a portion of tube 4 whose length is less than the width of the sill. The tensioning of the rope bridles it on the sills, and causes the immobilization of the tubes 4, which will remain embedded thereafter in the thickness of the concrete slab, thus allowing the recovery of the ropes after the completion of the book. On the frame of ropes thus formed, are placed wooden or chipboard 5, of sufficient thickness to produce a non-deformable formwork plane, ensuring perfect flatness of the slab at the time of pouring and drying thereof. this. Between the tube elements 4, and in the direction of the beams, the plates 5 rest on wooden battens 6, of thickness corresponding to the diameter of the cables plus a thickness of tube. On the plates 5, a welded mesh frame is arranged. The width of the expansion joints is obtained by placing, before casting, flat bars 7 placed on the field, the upper edge of these lying at the level provided for the upper face of the slab, These flat irons are held in place by means of sup _- Phillips ports 8 arranged at each intersection of expansion joints. The upper edge of the flat irons 7 makes it possible to pull the casting platform with the vibrating rule, these flat irons then being removed after drying of the platform.

To avoid any stagnation of rainwater on the court, and allow its rapid drying, it can be incorporated, at the time of the pouring of the concrete slab, a certain quantity of hollow frustoconical dowels 9, with cylindrical base provided with a collar implanted in holes provided for this purpose in the panels 5. These dowels, made of plastic for example, are arranged large base downward, to allow the evacuation of water to the existing vacuum zone under the platform, without risk of obstruction which could be caused by sand or gravel.

The invention is not limited to the embodiment of its various specially indicated parts, but it admits all possible variants, provided that these are not in contradiction with the subject of each of the claims appended to this description .

Thus it can be envisaged, without departing from the scope of the invention, to allow the recovery of formwork panels 5; in this case, these are limited in width to two lateral strips 5a and 5b, between which the panel rests, still supported by the ropes 2, this width is less than the spacing of the struts, so as to be able to extract the panels once they have fallen after the ropes have been removed. For facilitate their fall, the contiguous edges of the pan _nea flow with the bands 5a and 5b are inclined so as to form an undercut avoiding blocking therewith; during the implementation of the formwork before pouring concrete, the joints are lined with a strip 10, of triangular section, in foam or in any other similar material, the lateral strips 5a and 5b and the battens 6 are fixed on the side rails using steel spikes. A mechanical connection can be provided between the panels, in order to facilitate their extraction after their fall between the stringers after removal of the ropes. This connection can be, for example, hooks hitching onto legs provided with holes, each panel then being equipped with hooks at one end, and legs at the other end. The evacuation of rainwater is then ensured in this case by means of frustoconical hollow pegs 11, the base of which is provided with a collar allowing their fixing by gluing on a sheet 12 of waterproof felt, or of bidine, deposited on the chipboard before pouring the slab, It can also be envisaged to install in the panels 5 solid, conical metal dowels 13, fixed by nut on said panels and recoverable with them at the time of formwork,

In FIG. 11, a section of sill 1 has been illustrated, in reinforced or unreinforced concrete, provided with notches 14 formed at regular intervals. These intervals may represent for example, by way of nonlimiting indication, approximately 50 cm. The notches 14 are made when the concrete sill 1 is poured; various known means can be used for this purpose. A simple way is to use a chamfered ruler positioned in the theoretical axis of the notch; it suffices to proceed with the fitting and removal of the rule. During such an operation, it is absolutely essential to avoid tearing off the edges of the notch.

The notches 14 are intended to allow the passage of steel cables which constitute a frame.

FIG. 12 illustrates in detail, a notch 14, in particular its V-shape with rounded base. According to the invention, it is possible to envisage other geometric shapes for the notch 14; by way of example, a prismatic shape, however, in the implementation of the invention, it has been found that such a V shape with rounded base gives very good results. The dimensions of such a notch 14 are substantially, both in width and in depth, of the order of 1.5 cm.

FIG. 13 illustrates the assembly of the various elements during the implementation of the method of the invention.

In this figure, we see a longine 1 on which a rope 2 is placed. On each rope 2, the whole of which constitutes a frame, we place plates (wood or chipboard) or formwork panels 5, the thickness of which is sufficient to produce a non-deformable formwork plane ensuring perfect flatness of the concrete slab 15, at the time of casting, and of drying thereof.

In this embodiment, provision is made for the incorporation of a light sheet 16, which overflows on the formwork panels 5 making it possible to remove the ropes 2 after drying of the concrete slab.

This sheet 16 remains in the mold; it also has an effect of strengthening the whole,

To ensure perfect positioning of the sheet 16, the latter is nailed to the sill 1 using any suitable means, using nails 17, only one of which has been illustrated in the figure.

The sheet 16 has the effect of preventing the passage of concrete, since it covers both a sill 1 and a panel 5, and prevents the pouring of lost concrete.

The sheet 16 is a light sheet whose dimension can be of the order of 0.33 m x 2.55 m. It is, for example, a strip 0.4 mm thick.

In Figure 14, there is shown an overview of several beams 1, formwork panels 5 whose width is less than the spacing of the beams 1, the ropes 2 and the sheets 16; the installation sequence is always the same: the cables 2 are inserted, the panels 5 are then placed, the sheets 16 are then passed, _ finally the concrete slab 15 is poured.

According to Figure 15, there is illustrated in perspective a detail concerning the establishment and removal of the formwork panels; thus, more precisely in this FIG. 15, the two arrows 17 designate the direction of the sills 1, the ropes are designated by 2 and the formwork panels by 5, 18 represent straps which leave a gap between the panels 5. The straps 18 are stapled to the panels 5, they will enable the said panels 5 to be removed.

Figures 16 and 17 illustrate schematically ment the relationship between the panels 5 and the straps 18.

In the formwork position, the panels are obviously close together; this results in the formation of loops or recesses in the straps, one of which, 19, has been illustrated in FIG. 17.

After the concrete slab has dried, to remove formwork, the ropes 2 are removed, which has the effect of causing the fall of a line of panels 5, which are recovered by traction on the straps 18 which connect them.

The folding obtained is shown in Figure 16; this is a preferred mode according to the invention.

The process which is the subject of the invention can be used in the production of all horizontal concrete slabs separated from the ground by a crawl space, and more particularly sports fields and tennis courts.

Claims (11)

1 / Method for constructing thin concrete slabs, for the production of platforms located a few centimeters above the ground, and more particularly of platforms used for the practice of sports, such as tennis, characterized in that it consists in maintaining a non-deformable formwork plane at the desired distance from the ground, by means of supports recoverable after the casting and the drying of the platform, and in simultaneously producing the expansion joints necessary for the good performance of said platform by means of removable means, which means make it possible to carry out the drawing with the vibrating rule of the whole of the platform. 2 / A method according to claim 1, characterized in that the means of supporting the formwork plane at a certain distance from the ground is a frame of parallel steel ropes stretched transversely to beams of reinforced concrete or not, arranged parallel on the ground across the width of the structure, which ropes; moored at each end to stakes driven into the ground outside the structure, constrain by their tensioning the upper face of the stringers. 3 / A method according to claims 1 and 2, characterized in that the cables pass directly over each sill a notch and / or a portion of tube, which is embedded in the concrete slab during the casting of the slab , leaving the possibility of sliding the rope for its removal after casting. 4 / A method according to claims 1, 2 and 3, taken together, characterized in that the plane of non-deformable formwork consists of wooden or agglomerated sheets of sufficient thickness to avoid any deformation of flatness during the casting and drying of the platform, which wooden plates are placed on the frame of steel ropes . 5 / A method according to claim 4, characterized in that each plate constituting the formwork plane rests, by its longitudinal edges, on wooden battens and / or on a sheet placed on the sills and in the direction thereof between the elements of tubes, the thickness of said battens corresponding to the diameter of the rope plus the thickness of the tube. 6 / A method according to claim 4, characterized in that each plate constituting the formwork plane is formed in the direction of the width, two lateral strips and a central strip, which strips rest on the frame of steel ropes , which lateral bands are fixed integrally with the wooden battens placed on the sills and in the direction of these interposed between the tube elements, which central strip, of width less than the spacing of the sills, has its edges joined with the lateral strips in clearance, so as to facilitate its fall into the vacuum zone located under the slab after the removal of the ropes for recovery, and in that straps stapled to the plates are provided for their removal. 7 / A method according to claims 4 and 5, characterized in that the plates constituting the formwork plane comprise, uniformly distributed, frustoconical hollow dowels with cylindrical base drique provided with a collar implanted in the thickness of the plates, large base downwards, the height of the conical part corresponding to the thickness of the slab, which pegs, embedded in the concrete, allow the evacuation of rainwater to the existing vacuum zone under the slab. 8 / A method according to claims 4 and 6, characterized in that the recoverable plates constituting the formwork plane have, uniformly distributed, solid frustoconical dowels, implanting in the thickness of the plate and held by nut, in order to achieve during demoulding as many orifices allowing the evacuation of rainwater towards the vacuum zone existing under the slab. 9 / A method according to claims 4 and 6, characterized in that the evacuation of rainwater is provided by frustoconical hollow pegs, glued at regular intervals on a sheet of waterproof felt placed on the formwork plates before pouring the slab , 10 / A method according to claims 1 and 4, characterized in that the slab is squared by lines of orthogonal expansion joints, the spacing of which corresponds to the length and to a multiple of the width of the formwork plates, the width of which expansion joints is determined by the thickness of flat bars arranged on the field and held at their intersection by cruciform supports allowing their removal after use, the edge of which flat bars corresponding to the planned upper level of the slab to be cast thus constituting a plane of reference for the drawing with the vibrating rule of the whole of the slab after its casting. 11 / Playground obtained, in particular tennis court, by the implementation of the method according to any one of claims 1 to 10.

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