EP2549028A1 - Method for manufacturing a suspended structure and set of formworks for implementing same - Google Patents

Abstract

The method involves installing an absorptive support formwork (1) on a support (100) e.g. built structure, for receiving ends of support bearings (8) and ends of structural beams (2.1), where the formwork includes a series of notches to receive and brace the beams. Concrete is poured into the formwork for securing the support bearings with the formwork. The beams and reinforcement are positioned. A sealing profile (2.3) is positioned between each pair of adjacent beams, where absorptive formworks of the beams and the profile are made of ultra-high performance fiber-reinforced concrete plates. The structural beams are floor beams, deck beams or longitudinal ribs. An independent claim is also included for an absorptive ultra-high performance fiber-reinforced concrete formwork assembly for forming a support structure.

Description

The present invention relates to a method of constructing supported structures of concrete. The method of the invention particularly relates to the construction of bridges, walkways and floors of buildings. The invention also relates to a formwork assembly for implementing the method of the invention.

A supported structure is a substantially flat concrete construction having ends resting on supports. The representative structure of this type of construction is a building floor or deck deck or bridge.

Two main modes of concrete bridge construction are known: formwork and casting on site and prefabrication in the factory followed by assembly on site. The choice of the construction method is determined by considering the specific requirements of the site which can be of a technical nature (constraints of realization: accessibility, meteorological conditions), economic (cost of the operations), structural (competences / available resources).

The bridges with concrete structure generally comprise reinforcing elements forming reinforcements intended to take up tensile, shear and bending forces.

The formwork of the concrete elements consists of the realization of "molds" in the shape of the desired element. They are made from specific materials including able to withstand the exothermic behavior of the concrete when it is taken, and receive reinforcement to strengthen the concrete elements.

• les coffrages doivent être rigoureusement étanches ;
• ils doivent être capables de reprendre les charges de coulage (poids du béton et pression d'injection) sans se déformer afin de respecter la géométrie de l'ouvrage fini ;
• les ferraillages doivent comprendre un enrobage minimum de béton afin d'être préservés de la corrosion. Ainsi il est nécessaire de disposer des cales entre les fers des armatures et le coffrage afin de réaliser l'épaisseur d'enrobage requise (exceptionnellement inférieure à 2 cm).

A special precaution must be taken in their realization and their assembly because:

• the formwork must be tightly sealed;
• they must be able to take up the casting loads (concrete weight and injection pressure) without deforming in order to respect the geometry of the finished work;
• the reinforcement must include a minimum concrete coating in order to be protected from corrosion. Thus it is necessary to have shims between the reinforcing bars and the formwork to achieve the required coating thickness (exceptionally less than 2 cm).

These formwork are mounted on site to the exact location of the element whose outlines they define. The vertical panels are frequently traversed by cylindrical metal profiles connecting the elements facing each other and passing through furs, often made of plastic, in order to avoid their sealing when setting the concrete. These profiles are intended to take up the pressure exerted on the vertical walls by the concrete. Once assembled, adjusted and their geometry controlled, the forms are filled with concrete and possibly vibrated. After a set period of several days, the formwork is carefully deposited and the concrete elements thus obtained are checked. It is then that the following characteristics can be observed: recovery of the entire reinforcement by the concrete, integrity of the coating, bubbling, appearance of the finished concrete. The passage holes of the furs are then rebouched.

• coffrage à usage unique (tubes de cartons, planches de bois) ;
• coffrage réutilisable (lors de la réalisation de plusieurs éléments identiques comme des piles de pont architecturales ou des panneaux de béton ouvragés) ;
• coffrage modulaire (essentiellement utilisé pour la réalisation d'éléments droits ou plans) comportant des éléments assemblables composés d'une structure métallique sur laquelle sont fixés des peaux de coffrage métalliques destinées à être en contact avec le béton.

There are essentially 3 types of formwork:

• single-use formwork (cardboard tubes, wooden boards);
• reusable formwork (when making several identical elements such as architectural bridge piers or concrete panels works) ;
• modular formwork (essentially used for producing straight or planar elements) comprising assemblable elements composed of a metal structure on which are fixed metal form skins intended to be in contact with the concrete.

The advantages of these solutions lie in the fact that the elements being cast in place, no transport of great weight / great length is necessary. An apron of 12 meters by 4 meters, which corresponds to a 2-lane road bridge deck, can be poured by the continuous supply of routers and thus requires only transport whose unit load allows the passage on any type road or bridge, without prior administrative authorization or special escort.

This type of embodiment, however, requires the intervention of formers who are highly skilled workers and technicians forming a scarce and expensive labor. Handling means for posting the formwork materials are required, these means are also necessary during the removal of the formwork, once the concrete taken. The conformity of the coating of the irons is discovered only with the use or by non-destructive control. These forms are expensive: they represent about 40 to 60% of the price of reinforced concrete and the use of reusable formwork increases the weight thereof and therefore impacts the handling means. The formwork removal phase penalizes the schedule. The facing to be obtained (appearance of the finished concrete) requires a lot of care during the installation of the formwork, especially for the architectural renderings. The structures include traces of filler holes that remain visible, unsightly and can be a source of leakage (river structures). Correct stripping requires the application of toxic release agents prior to concrete operations, which poses particular difficulties for river works. The re-use of formwork on the same structure, in order to reduce the financial impact, requires a phasing of work that weighs heavily on the schedule. Sometimes, the very configuration of the premises precludes the use of formwork for reasons of congestion footstocks or environment.

Prefabrication consists in dividing the structure into sub-elements, manufacturing these in the factory and transporting them to the site where they will be assembled to reconstitute the final work. The sub-elements have systems allowing their solidarity. These are usually armatures arranged projecting prefabricated sub-elements and intended to be embedded in a junction concrete. The sub-elements are usually produced in specialized factories using reusable formwork under controlled environmental conditions with smaller quantities of concrete. The ability to cast the element in a position that is not necessarily the one it occupies in the book also allows better control of the various concrete parameters. This solves the problems of availability of on-site skills, shortens the onsite response time by eliminating the time of formwork and stripping, and on-site concrete supply constraints. However, prefabrication, to be economical, requires the realization, transport and handling of massive elements. This results in high transport costs (exceptional large-size / large loads) and handling (need for larger lifting). There are also parts of the structure that can not be prefabricated, including the anchor beds of the deck, which solidarize it with the foundation piles.

Bridges with a metallic structure can appear as a solution allowing a gain of weight. Indeed, steel is comparatively lighter than concrete for similar efforts. Thus, for the same load recovery by a prefabricated element, the mass to be handled is less for the steel sub-element. The metal structure to be produced is divided into sub-elements. These metal elements are prefabricated and painted before being transported to the site. They are then put in place and assembled, usually by bolting or welding. However, steel remains a much more expensive raw material than concrete. Steel requires costly corrosion protection and continued maintenance which, in practice, is often neglected.

Problems similar to those described above can arise for the manufacture of large supported structures in other applications and especially in the building.

• au contact de l'eau, ceux-ci deviennent glissants et nécessitent donc l'application de revêtement anti-dérapant par collage ou réalisation d'aspérités ;
• les platelages en bois grisent avec le temps et sont l'objet de déformations (vrillage, flambement, flèche) provoquées par les changements d'hygrométrie, l'exposition aux UV, l'alternance des cycles de gel/dégel et l'utilisation des sels de déverglaçage ;
• les platelages métalliques sont moins sensibles aux variations géométriques mais demandent la mise en oeuvre de matériaux coûteux (inox) afin d'assurer une durabilité suffisante.

Footbridges represent a particular category of bridge subject to crossing loads that do not include road or rail loads. The circulation is generally carried out on a decking extending between two longitudinal beams. This deck is frequently made of transverse elements of wood or metal spaced from each other in order to be able to evacuate the rainwater and to offer a pleasant perception of the void under the bridge. Such decks, however, have several disadvantages:

• in contact with water, these become slippery and therefore require the application of anti-slip coating by gluing or making asperities;
• wooden decking becomes gray over time and is subject to deformation (twisting, buckling, booming) caused by changes in hygrometry, UV exposure, alternating freeze / thaw cycles and the use of de-icing salts;
• metal decking is less sensitive to geometric variations but requires the use of expensive materials (stainless steel) to ensure sufficient durability.

An object of the invention is to provide a method of producing simple and economical supported structures, which can be implemented by a normally skilled labor and using light handling means.

1. a) installer sur les appuis un coffrage d'appui destiné à recevoir d'une part les extrémités des attentes d'appui et d'autre part des extrémités de coffrages de poutres de structure, chaque coffrage d'appui comportant une série d'encoches destinées à recevoir et entretoiser des poutres de structure,
2. b) couler du béton dans les coffrages d'appui pour solidariser les coffrages d'appui et les attentes d'appui,
3. c) mettre en place les coffrages de poutres de structure et un ferraillage,

For this purpose, there is provided, according to the invention, a method of producing a supported structure resting locally on supports. The method comprises the steps of:

1. a) installing on the supports a support formwork intended to receive on the one hand the ends of the support expectations and on the other hand the ends of structural beam formwork, each support formwork comprising a series of notches for receiving and bracing structural beams,
2. b) pouring concrete into the support forms to secure the support forms and the support expectations,
3. c) install structural beam formwork and reinforcement,

• d) mettre en place un profilé d'étanchéité entre chaque paire de poutres de structure adjacentes,
• e) couler du béton pour remplir les coffrage les coffrages d'appui, les coffrages de poutres de structure et les profilés d'étanchéité étant des coffrages perdus en BFUP.

According to a first embodiment, the method also comprises, following these first steps, the steps of:

• d) put in place a sealing profile between each pair of adjacent structural beams,
• e) casting concrete to fill the formwork the support forms, structural beam formwork and sealing profiles being formwork lost in UHPC.

• d') mettre en place les éléments transversaux;
• e') couler du béton pour remplir les coffrages; les coffrages d'appuis, les coffrages de poutres de structure et les éléments transversaux étant en BFUP ;
• f') poser un chaperon de protection sur la partie supérieure du coffrage de la poutre de structure.

According to a particular embodiment, the formwork of structural beams comprising, on at least one wing, notches for receiving and bracing transverse elements, the method also comprises following these first steps, the steps of:

• d) set up cross-cutting elements;
• e ') pouring concrete to fill the formwork; support formwork, structural beam formwork and transverse elements being in UHPC;
• f ') install a protective hood on the upper part of the formwork of the structural beam.

The forms are ultra-high performance fiber-reinforced concrete formwork (UHPCF) whose mechanical characteristics are added to those of concrete and reinforcement to form those of the finished work. They are advantageously prefabricated in the factory. These forms are preferably self-supporting insofar as they do not require support, their structure then being arranged to allow the recovery of efforts due to reinforcement and casting.

• les coffrages sont aisément manutentionables car ils ne représentent que l'enveloppe des poutres dont ils ont la forme. Ainsi les manutentions peuvent être réalisées avec des moyens légers usuels voire manuels ;
• dans le cas particulier des ouvrages soutenus dont la portée est de l'ordre de 12 mètres ou inférieure, tous les éléments sont transportables par des semi-remorques standard, sans besoin d'autorisation ou d'escorte particulière ;
• les coffrages préfabriqués ne nécessitent que peu de compétences pour être mis en place, le système de coffrage pouvant intégrer des dispositions constructives destinées à assurer le positionnement des éléments les uns par rapport aux autres ;
• l'utilisation de coffrages perdus en BFUP élimine la phase de décoffrage et les matériels nécessaires à celle-ci. L'avantage d'une maintenance réduite par rapport à l'emploi de structures métalliques est conservé.

This solution has the following advantages:

• the formwork is easily handled because it represents only the envelope of the beams of which they have the form. Thus handling can be performed with light means customary or manual;
• in the particular case of supported structures whose range is of the order of 12 meters or less, all elements are transportable by standard semi-trailers, without the need for authorization or escort particular;
• prefabricated formwork requires little skill to be implemented, the formwork system can incorporate constructive provisions to ensure the positioning of the elements relative to each other;
• the use of formwork lost in BFUP eliminates the phase of formwork and the materials necessary for it. The advantage of reduced maintenance compared to the use of metal structures is retained.

The support forms will advantageously be provided with a system of lights and washers that allows to absorb the tolerances of installation and verticality of the expectations of the support structure: anchoring piles or reinforcement of head of posts or masonry.

Depending on the handling means available, the UHPFF formwork will be able to receive, as soon as it is prefabricated, the internal reinforcement of the beams whose edges they define. These reinforcements may be partially secured by a first limited concreting during prefabrication. These frames can be prestressed, to avoid the realization of these expensive operations on the site after assembly. Finally, longitudinal strands, prestressed or not, are preferably embedded in the BFUP heel of the beams and provide them with sufficient strength to allow to recover relatively large efforts.

The invention makes it possible to achieve, at lower cost, a supported structure whose manufacture does not involve any exceptional transport or particular lifting means. Operations requiring qualified or even highly skilled labor (formwork, prestressing) are eliminated from the site. The facing of the structure is controlled, the amount of concrete to bring on site is reduced, the presence of toxic products zero. Finally the realized work has the facilities of maintenance of a work free of external metallic elements. The proper coating of the reinforcements is also guaranteed.

The invention also relates to a set of formwork lost in UHPF for the implementation of this method.

Other features and advantages of the invention will emerge on reading the following description of particular non-limiting embodiments of the invention.

• la figure 1 est une vue d'ensemble, selon un premier mode de réalisation de l'invention, des coffrages avant bétonnage pour la réalisation d'un tablier de pont ;
• la figure 2 est une vue du coffrage d'appui pour la réalisation d'un tablier de pont selon le mode de réalisation de la figure 1;
• la figure 3 est une vue représentant un coffrage de poutre de structure lié par un profilé d'étanchéité en C à un coffrage de rive pour la réalisation d'un tablier de pont ou un plancher selon le mode de réalisation de la figure 1;
• la figure 4 est une vue d'ensemble des coffrages avant bétonnage d'un deuxième mode de réalisation de l'invention pour la confection d'un plancher ;
• La figure 5 est une vue représentant un coffrage de poutre de structure lié par un profilé d'étanchéité en Π à un coffrage de rive pour la réalisation d'un tablier de pont ou d'un plancher ;
• la figure 6 est une vue d'ensemble, en perspective partiellement écorchée, des coffrages avant bétonnage pour la réalisation d'une passerelle conformément à un troisième mode de réalisation de l'invention;
• la figure 7 est une vue du coffrage d'appui pour la réalisation d'une passerelle selon le mode de réalisation de la figure 6;
• la figure 8 est une vue en coupe représentant un coffrage de poutre de structure lié par un élément transversal à un autre coffrage de poutre de structure pour la réalisation d'une passerelle selon le mode de réalisation de la figure 6;
• la figure 9 est une vue en coupe d'une poutre de structure munie d'un chaperon de protection, selon le mode de réalisation de la figure 6 ;
• la figure 10 est une vue d'ensemble représentant un élément transversal, selon le mode de réalisation de la figure 6.
• la figure 11 est une vue représentant la section de l'élément transversal de la figure 10.

Reference will be made to the appended drawings, among which:

• the figure 1 is an overview, according to a first embodiment of the invention, formwork before concreting for the realization of a bridge deck;
• the figure 2 is a view of the support formwork for the realization of a bridge deck according to the embodiment of the figure 1 ;
• the figure 3 is a view showing a structural beam formwork bonded by a C-shaped sealing profile to an edge formwork for the realization of a bridge deck or floor according to the embodiment of the figure 1 ;
• the figure 4 is an overview of formwork before concreting a second embodiment of the invention for making a floor;
• The figure 5 is a view showing a form of structural beam formwork connected by a sealing profile in Π to a formwork of bank for the realization of a bridge deck or a floor;
• the figure 6 is an overall view, in perspective partially broken away, formwork before concreting for the realization of a bridge in accordance with a third embodiment of the invention;
• the figure 7 is a view of the support formwork for the realization of a bridge according to the embodiment of the figure 6 ;
• the figure 8 is a sectional view showing a structural beam formwork joined by a transverse element to another structural beam formwork for the realization of a bridge according to the embodiment of the figure 6 ;
• the figure 9 is a sectional view of a structural beam provided with a protective chaperone, according to the embodiment of the figure 6 ;
• the figure 10 is an overview showing a transverse element, according to the embodiment of the figure 6 .
• the figure 11 is a view representing the section of the transverse element of the figure 10 .

The invention relates to a method of manufacturing a supported structure and a set of forms for this purpose.

A first embodiment consists of the construction of a bridge for crossing a gap of about twelve meters. The bridge consists of two massifs designated 100 and an apron, generally designated 2, connected to the masses 100 by its ends. In this first embodiment, the structural beams 2.1 are apron beams 2.1.

The formwork set includes several formwork lost in UHPC. It thus comprises two support forms generally designated as 1, formwork of deck beams 2.1 and sealing profiles 2.3. The interior surfaces of the formwork are indented to ensure a good grip of the poured concrete in the lost forms while their external surfaces intended to be visible here are smooth to give the finished work its final surface state.

The apron beam formwork 2.1 comprises UHPC plates assembled to each other to form two webs and a heel arranged in a U-shaped profile. Two of the deck beam forms are intended to form the edges of the deck, said two forms having souls of different heights, the uppermost soul being intended to form a side edge of the apron. The formwork of apron beams 2.1 comprise, here, prestressed strands 2.4 extending longitudinally in their heel. These strands 2.4 reinforce the longitudinal strength of the deck beam formwork 2.1 and are dimensioned to allow the formwork of deck beams 2.1 to withstand the load of reinforcement, concreting and allow the movement of personnel involved in particular to achieve reinforcement transverse.

Each sealing profile 2.3 is arranged so as to seal between two adjacent deck beams 2.1. Each sealing profile 2.3 thus has a plate shape provided with lateral flanges and intended to extend astride the souls facing two adjacent beams, each rim being received between the webs of the same beam to ensure the maintenance lateral in position of the sealing profile.

The formwork of the bridge deck 2 thus consists of apron beam formwork 2.1 receiving reinforcement 2.2 and covered with adjacent forms by sealing profiles 2.3. The finished height of the deck is determined by the height of the outer webs of the bank beam formwork 2.5 which is ideally at the same level as the height of the flanks of the support formwork 1.

The two support forms 1 are of parallelepipedal shape and comprise, on their walls facing each other on either side of the breach to be crossed, a series of notches intended to accommodate the formwork of the deck beams 2.1 and the brace. The bottom of the support forms is pierced with several openings 1.2 intended to receive the salient expectations of the supports. Advantageously, the openings 1.2 will have dimensions allowing to absorb the implantation and verticality tolerances of the piles 8. Sealing washers 1.3, whose inner diameter makes it possible to engage the washer around the pile, are positioned before the implantation of the support casing 1. The outer contour of these washers 1.3 is adapted to achieve a seal with the opening 1.2 which may be circular, square or any shape and for example oblong. The sealing washers have external dimensions greater than those of the openings 1.2. This provision avoids prior site surveys. These mass forms 1 receive before concreting 1.4 reinforcement cages positioned at sufficient coating distance.

At first, the washers 1.3 are located on the support expectations on both sides of the gap. The formwork 1 is then positioned on the heads of the piles 8, the openings 1.2 allowing the passage of the pile heads and their presence inside the parallelepiped defined by each support casing 1. The washers 1.3 are recovered with the bottom support casing 1 and provide a seal for future concreting. A bead of suitable type sealant can be placed at the interface of these 2 elements if necessary.

The notches 1.1 made in the support formwork 1 are oriented towards the gap and face each other. The axes of the notches will be ideally aligned. A reinforcement cage 1.4 is then placed at the bottom of the supporting formwork 1, at a sufficient distance from the coating. A first layer of concrete is then poured, solidarisant the formwork and the base of the reinforcement cage with the heads of the piles. The level of this first layer is ideally located below the base of the notches 1.1.

Once this concrete is in process, the formwork of deck beams 2.1 are arranged between the two support forms 1 in the notches 1.1 facing each other. Their implementation does not require any particular control, the notches defining themselves the position of the apron beam formwork 2.1. Thus, a rigorous implementation of the support forms makes it possible to implement without special precaution the formwork of apron beams 2.1. The rigidity of these forms allows the movement of personnel on these beams and thus allows the laying of the longitudinal reinforcement 2.2 in the formwork of apron beams 2.1 by hand, to avoid the use of powerful handling means. The outer webs of the formwork of the deck beams 2.5 of the deck 2 comprise an excess length corresponding to the additional thickness of the slab and the raceway. Any additional reinforcement of the support forms 1 can then be made.

The sealing profiles 2.3 are positioned to connect the adjacent webs of the forms of 2.1. The formwork of the bridge is then complete. The transversal reinforcement can then be laid and the pouring apron start.

This concreting takes place ideally in a single phase and fills the support forms 1 with their reinforcements 1.4, the formwork of beams 2.1 with their reinforcements 2.2. The sealing profiles 2.3 allow the concrete to rise to the final level defined by the height of the flanks of the support casing 1 and the edge beams 2.5 of the deck 2. A reserve may be provided for the installation , after setting concrete, a rolling coating such as bitumen or macadam.

Prefabricated transition slabs 4 made of UHPC and supported by a compacted embankment are placed in support between the bridge and the road embankment. They will then be paved with the common wearing course at the road and at the bridge. For structures of the span of the bridge object of this embodiment, the neoprene road joints and supports are not useful.

Once the pouring of the poured concrete during the second and final concreting operation is complete, the bridge can receive its accessories (railing, wearing course, ground signaling paint, etc.).

A second embodiment consists of the construction of building floors. The floor rests on its ends on masonry supports: posts, beams or bearing walls projecting from which extend metal expectations. In this second embodiment, the beams of structures 2.1 are beams 6.1. The floor 2 consists of two support forms 1 connected by beams 6.1 and supporting a slab.

• des coffrages d'appui 1,
• des coffrages de poutrelles 6.1,
• des profilés d'étanchéité. 2.3,

The forms required for this realization are:

• support forms 1,
• 6.1 beam formwork,
• sealing profiles. 2.3

All these elements are made of UHPC and have the same construction arrangements as the formwork of the previous embodiment including: indented or ribbed inner surface, longitudinal strands preloaded 2.4, 1.1 holes providing the possibility to include the reinforcement beams 6.1 in the formwork ...

In this particular application, the realization of a floor supported by several supports as represented in fig.4 makes it necessary to implement an intermediate support formwork 1.5 having notches 1.1 on two of its faces.

The support forms 1 are arranged on posts 7. The extreme supports receive formwork 1, the supports of the intermediate bays receive support forms 1.5. All these support forms are provided in their bottom 1.2 cutouts allowing the passage 7.1 expectations emerging from the posts 7. These formwork positioned, they receive the 1.4 frames and are partially concreted. The beams formwork 6.1 are then positioned in the notches 1.1 and connect the formwork 1 and 1.5. The sealing profiles 2.3 are placed between the adjacent webs of two beams 6.1. Any transverse reinforcement can be installed. It will be noted that the souls in excess of the formwork of banks 2.5 can be advantageously replaced by the walls of the walls delimiting the building. The set of forms 1, 1.5, 6.1, 2.3, 2.5 or the walls of the building produces a closed volume in which are poured simultaneously the slab and the beams of the floor.

Once this concrete phase has been taken, the floor is finished.

Elements identical or similar to those previously described will bear a numerical reference identical to these in the description which follows of a third embodiment.

With reference to Figures 6 to 11 this third embodiment relates to the construction of a bridge 10 comprising a deck 11 composed of transverse elements 12, only part of which is shown in FIG. figure 6 . The bridge 10 rests at its ends on masses 100 projecting from which extend piles 8. In this particular embodiment, the support casings 1 are identical to those described above but have only two notches 1.2 facing the and the gaps at the ends of the largest edge of the support casing 1. The notches 1.2 of each support casing 1 face each other and receive structural beam formwork which are, here, longitudinal rib formings 13.1 shown in FIG. traits interrupted in figure 7 . These longitudinal rib formings 13.1 have a structure identical to the structural beams 2.1 previously described and each comprise, on their flanges facing each other, notches 14 in the shape of a T intended to accommodate the transverse elements 12. With reference to FIGS. Figures 10 and 11 , each transverse element 12 is prefabricated in UHPC and has a T-shaped section comprising a horizontal upper part 12.1 on which the circulation takes place and a lower part 12.2. A longitudinal reinforcement 15 embedded in the lower portion 12.2 of the transverse member 12 provides the shear and flexural strength thereof. The transverse element 12 has two expectations of reinforcement 12.3 each constituted by a projection of the armature 15 on either side of the transverse element 12.

The realization of the gateway 10 begins with the laying of the sealing washers 1.3 on the heads of the piles 8. The supporting forms 1 are then positioned on the pile heads 8 so that the notches 1.2 formed in each support form 1 are oriented towards the gap and that their axes are aligned. A reinforcement cage 1.4 is then placed at the bottom of the supporting formwork 1, at a sufficient distance from the coating. A first layer of concrete is then poured, solidarisant the support casing 1 and the base of the reinforcement cage 1.4 with the heads of the piles 8. The upper level of this first layer is ideally located below the base of the notches 1.2 .

Once this concrete is being set, the longitudinal rib formings 13.1 are arranged between the two support forms 1 in the notches 1.2 facing each other. Their implementation requires no particular control, the notches 1.2 defining themselves the position of longitudinal rib formings 13.1. Thus, a rigorous implementation of the support forms 1 allows to implement without special care longitudinal rib formings 13.1. The rigidity of these forms allows the movement of personnel on them and thus allows the installation of longitudinal reinforcement 2.2 in forms longitudinal ribs 13.1 by hand, to avoid the use of powerful handling means. A second concreting phase is then performed in order to fill the longitudinal rib formings 13.1 to the base of the lower part of the notch 14. The transverse elements 12 are then placed in the corresponding notches 14. The expectations of reinforcement 12.3 then protrude into each longitudinal rib formwork 13.1 a little above the level of previously poured concrete. The installation of these transverse elements 12 can be advance to a mobile frame equipped with a safety net and resting on the two longitudinal ribs 13.1.

Once all the transverse elements 12 placed in the notches 14, a final phase of concreting comes to cover the expectations of reinforcement 12.3 and completes filling longitudinal rib formings 13.1 and support forms 1. This phase of concreting allows sealing the constituent elements of the bridge 10 and their respective concreting phases: pile heads 8, support formwork 1, longitudinal rib formwork 13.1, transverse elements 12. With reference to FIG. figure 9 a protective chaperon 16, in the form of a plate of length and width identical to those of the longitudinal rib 13.1 and provided with a central tongue 17 projecting towards the inside of the longitudinal rib 13.1, is then placed contact fresh concrete. This chaperone thus closes the formwork of the bridge 10 which then has only UHPCF surfaces, the support forms receiving transition slabs 4 prefabricated in UHPC. The tongue 17 makes it possible to ensure effective sealing of the protective chaperon 16 with the concrete of the longitudinal rib formings 13.1. A railing 18 is then fixed vertically to each longitudinal rib 13.1 with the aid of mechanical pins 19 passing through the protection cap 16. This protective chaperone 16 has a return on one of its longitudinal edges coming to contact of the outer face of the longitudinal rib 13.1.

This provides a bridge 10 whose deck 11 has a strength and durability superior to existing gateway solutions.

Advantageously, the upper portion 12.1 of the transverse elements 12 comprises an upper surface 12.4 molded on wood matrix, thus giving the transverse element 12 the appearance of a wooden decking. The UHPC in which is composed the transverse element 12.1 can also be tinted to further emphasize the "wood" aspect of it.

Thus, the invention makes it possible to achieve, without the intervention of qualified labor or heavy lifting means, concrete structures supported in a fast and economical manner. These structures have the additional feature of allowing almost zero maintenance costs, the armatures being protected by a very durable UHPC skin. The fire resistance is increased by the skin in UHPC.

Of course, the invention is not limited to the embodiments described but encompasses any variant within the scope of the invention as defined by the claims.

• les coffrages peuvent intégrer des protrusions sur leurs faces internes destinées à caler les ferraillages à la distance d'enrobage minimale requise ainsi qu'à bloquer en position les armatures dans le coffrage ;
• les coffrages de poutres de structure 2.1 peuvent être moulés ou extrudé ;
• les coffrages de poutres de structure 2.1 ou d'appuis 1 peuvent intégrer, dès la préfabrication leurs armatures ;
• les coffrages de poutres de structure 2.1 peuvent intégrer les profils d'étanchéité : une des deux âmes comporte un élément saillant perpendiculaire à l'âme et dirigé vers l'extérieur du coffrage. Cet élément est implanté de manière tangente à la partie supérieure de l'âme et a une longueur lui permettant de reposer sur une autre protrusion destinée à le recevoir et implantée sur l'âme de l'élément suivant ;
• les coffrages peuvent intégrer des oreilles ou poignées de manutention ou de levage, renforcées ou non d' armatures ;
• la section des coffrages de poutres de structure 2.1 peut être en I en T ou en TT avec l'intégration de tout ou partie du ferraillage nécessaire ;
• les coffrages peuvent ne pas contenir d'éléments de précontrainte ;
• les armatures peuvent être actives ou passives, éventuellement précontraintes lors de la préfabrication ou après bétonnage sur site ;
• l'espacement des coffrages de poutres de structure 2.1 peut être réalisé à l'aide de peignes de positionnement ;
• les plaques en BFUP peuvent recevoir, dès la préfabrication la finition définitive requise : enduite, lasurée, engravée ;
• les profilés d'étanchéité 2.3 peuvent avoir une section en Π (figure 5) ;
• bien que, ici, les encoches 14 reçoivent des éléments transversaux 12 dont la section est en T, l'invention s'applique également à d'autres formes d'encoche et de section de poutres correspondantes comme par exemple des sections rectangulaires, en L, en I ;
• bien qu'ici, la passerelle 10 ne comprenne que deux nervures longitudinales 13.1, l'invention s'applique également à une passerelle comprenant plus de deux nervures longitudinales, les nervures additionnelles étant pourvues sur leurs deux faces d'encoches accueillant des éléments transversaux 12 ;
• bien que, ici, les éléments transversaux 12 soient réalisés en BFUP, l'invention s'applique également à des éléments transversaux réalisés en d'autres matières comme par exemple la pierre, le bois, le métal, le béton standard ;
• bien que, ici, une face supérieure 12.4 de l'élément transversal 12.1 soit moulée sur matrice bois, l'invention s'applique également à des éléments transversaux n'ayant aucun moulage en partie supérieure ou portant d'autres types de moulages tels que indentations, larmes, rainures, ergots anti-dérapants ;
• bien que, ici, le chaperon de protection 16 soit fixé au béton remplissant les nervures longitudinales 13.1 par scellement, l'invention s'applique également à d'autres modes de fixation comme le chevillage mécanique ou chimique ;
• bien que, ici, un béton est coulé dans les nervures longitudinales 13.1 avant la pose des éléments transversaux 12, l'invention s'applique également à une unique phase de bétonnage solidarisant les armatures longitudinales 2.2, le coffrage de nervure longitudinale 13.1 et les éléments transversaux 12 avec les coffrages d'appui 1 et les massif 100.

In particular :

• the formwork can incorporate protrusions on their internal faces intended to wedge the reinforcement to the minimum required coating distance and to lock in position the reinforcement in the formwork;
• structural beam formwork 2.1 may be molded or extruded;
• the formwork of structural beams 2.1 or supports 1 can integrate, from the prefabrication their armatures;
• Structural beams formwork 2.1 can integrate the sealing profiles: one of the two cores comprises a projecting element perpendicular to the core and directed outwardly of the formwork. This element is implanted tangentially to the upper part of the core and has a length allowing it to rest on another protrusion intended to receive it and implanted on the soul of the next element;
• the formwork may incorporate lugs or handles for handling or lifting, reinforced or not with reinforcements;
• the section of structural beam formwork 2.1 may be I T or TT with the integration of all or part of the necessary reinforcement;
• the formwork may not contain prestressing elements;
• the reinforcements may be active or passive, possibly prestressed during prefabrication or after concreting on site;
• the spacing of structural beam formwork 2.1 can be achieved by means of positioning combs;
• the plates in UHPC can receive, as soon as prefabrication, the final finish required: coated, stained, engraved;
• the sealing profiles 2.3 may have a section in Π ( figure 5 );
• although, here, the notches 14 receive transverse elements 12 whose section is T, the invention also applies to other forms of notch and section of corresponding beams such as rectangular sections, L in I;
• although here, the bridge 10 comprises only two longitudinal ribs 13.1, the invention also applies to a bridge comprising more than two longitudinal ribs, the additional ribs being provided on their two faces with notches hosting transverse elements 12 ;
• although, here, the transverse elements 12 are made of UHPC, the invention also applies to transverse elements made of other materials such as stone, wood, metal, standard concrete;
• although, here, an upper face 12.4 of the transverse element 12.1 is molded on a wood matrix, the invention also applies to transverse elements having no molding at the top or carrying other types of moldings such as indentations, tears, grooves, anti-slip lugs;
• although, here, the protective chaperon 16 is fixed to the concrete filling the longitudinal ribs 13.1 by sealing, the invention also applies to other modes of attachment such as mechanical or chemical pinning;
• although, here, a concrete is poured into the longitudinal ribs 13.1 before the laying of the transverse elements 12, the invention also applies to a single concrete phase solidarisant the longitudinal reinforcement 2.2, the longitudinal rib formwork 13.1 and the elements transverse 12 with the support forms 1 and the solid mass 100.

Claims (23)

Process for producing a supported structure (2) resting locally on supports (100; 7), comprising the steps of: a) to install on the supports (100; 7) a support casing (1) intended to receive, on the one hand, the ends of the support expectations (7.1; 8) and on the other hand the ends of the beam formwork forms; structure (2.1), each supporting formwork (1) having a series of notches (1.1) for receiving and bracing structural beams (2.1), b) pouring concrete into the support formwork (1) to secure the support forms (1) and the support expectations (7.1; 8), c) install structural beam formwork (2.1) and reinforcement (2.2). The method of claim 1, further comprising the steps of: d) setting up a sealing profile (2.3) between each pair of adjacent structural beams (2.1), e) pouring concrete to fill the formwork, the support formwork (1), the structural beam formwork (2.1, 2.5) and the sealing profile (2.3) being formwork lost in the UHPC. A method according to claim 1, wherein the formwork of the structural beams (2.1) comprise, on at least one wing, notches (14) for receiving and bracing transverse elements (12), the method also comprising the steps of: d ') set up the transverse elements (12); e ') pouring concrete to fill the formwork, the support formwork (1), the beam formwork structure (2.1) and transverse elements (12) being in UHPC; f ') put a protective chaperon (16) on the upper part of the formwork of the structural beam (2.1). Method according to claim 1, comprising, prior to the installation of the support casings (1) on the supports (100; 7), a step of setting up, around each waiting of support (7.1; 8), a sealing washer (1.3) in UHPC, the support formwork (1) having a bottom pierced with openings (1.2) for the passage of the waiting support (7.1; 8) with a clearance intended to compensate an implantation tolerance of the support expectations (7.1; 8), the sealing washers (1.3) having outer dimensions greater than those of the openings. Method according to claim 2, wherein the supports (100) are masonry structures or columns (7), the structural beams (2.1) are beams (6.1) and the supported structure (2) is a floor. A method according to claim 2, wherein the supports (100) are piles or foundations, the structural beams (2.1) are deck beams and the supported structure (2) is then a deck deck. A method according to claim 3, wherein the supports (100) are piles or foundations, the structural beams (2.1) are longitudinal ribs (13.1) and the supported structure (10) comprises a decking (12). gateway (10). Method according to Claim 1, in which an intermediate support formwork (1.5) resting on an intermediate support (100; 7) ensures the connection of two adjacent supported structures (2). The method of claim 1, wherein at least a portion of the reinforcement (2.2) is pre-assembled in structural beam formwork (2.1). Method according to claim 1, wherein the structural beam formwork (2.1) or the support formwork (1) incorporate at least one longitudinal prestressing element (2.4) embedded in the UHPC. Set of lost formwork in UHPC for the implementation of the method according to any one of the preceding claims, comprising at least one support formwork (1) and formwork of structural beams (2.1). An assembly according to claim 11 further comprising sealing profiles (2.3). An assembly according to claim 11, wherein the support casing (1) is substantially parallelepipedal and has a bottom pierced with openings (1.2) to accommodate support expectations (7.1; 8) and a side wall pierced with notches (1.1) for receiving and bracing the structural beam formwork (2.1), the supporting formwork (1) being arranged to receive the reinforcement (1.4) of the element of which it constitutes the envelope. An assembly according to claim 11, wherein each structural beam formwork (2.1) is arranged to receive the reinforcement (2.2) of the beam of which it constitutes the envelope. Assembly according to claim 11, wherein each formwork of structural beams (2.1) comprises two webs extending on either side of a bead, two of the structural beam formwork (2.1) being intended to form banks (2.5) of the supported structure (2), said two structural beam formwork (2.1) having souls of different heights, the highest core being intended to form a lateral edge of the supported structure (2). An assembly according to claim 11, wherein the sealing profile (2.3) is arranged to seal between two adjacent structural beams (2.1). An element according to claim 11, wherein the inner face of the UHPCF forms has a surface condition facilitating the resumption of concreting. An assembly according to claim 11, wherein a support formwork (1) has two series of notches (1.1) arranged to accommodate structural beams (2.1) projecting from two different supports. A method according to claim 1 to 3, wherein the structural beam formwork (2.1) consists of BFUP plates assembled to preferably form a U-shaped cross-section. A method according to claim 2, wherein the sealing profiles (2.3) consist of BFUP plates assembled to form an inverted C or Π cross-section so as to overlap webs opposite structural beam formwork (2.1). ). The method of claim 3, wherein the protective chaperone (16) is made of UHPC. The method of claim 3, wherein the notches (114) of the structural beams (2.1) are T-shaped. The method of claim 3, wherein at least one decking cross member (12) has a wood matrix molded face (12.4).

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