WO2013164519A1

WO2013164519A1 - Formwork and associated floor

Info

Publication number: WO2013164519A1
Application number: PCT/FR2012/000175
Authority: WO
Inventors: Vincent Birarda; Trung LUU
Original assignee: Arcelormittal Investigación Y Desarrollo Sl
Priority date: 2012-05-03
Filing date: 2012-05-03
Publication date: 2013-11-07
Also published as: EP2844809B1; WO2013164677A1; ES2626171T3; EP2844809A1

Abstract

The invention mainly concerns a formwork for a steel-concrete composite floor comprising: - a self-supporting profile comprising at least one upper central sheet, lateral cores extending the upper central sheet on either side of same and towards the underside, and at least two lower footings extending the lateral cores, - a spacer profile comprising at least one upper plate and two lateral wings extending the upper plate on either side of same and towards the underside, the spacer profile being disposed, at least by the end of the lateral wings, on the self-supporting profile so as to at least partially cover the upper central sheet and thus form at least one casing. The invention also concerns the associated manufacturing method and manufacturing kit and a steel-concrete composite floor and the associated manufacturing method.

Description

Formwork and associated floor

The present invention relates to a formwork for the construction of mixed steel-concrete floors obtained by casting a concrete slab on the formwork.

It is known in the field of construction to use metal formwork to facilitate the manufacture of floors. These formworks, consisting of a metal sheet shaped generally by profiling, are arranged, via their ends, on the structure of the building under construction and retain the poured liquid concrete until it dries and forms the slab of the floor.

Depending on the form of the formwork, the floor obtained can be of 3 different types: with lost formwork, additive or collaborating. By loose form flooring, it is meant that only concrete contributes to the mechanical strength of the floor. By additive floor, it is meant that the mechanical strength of the floor is the addition of the respective strengths of the formwork and concrete. Finally, collaborating floor means that the resistance of the floor is greater than the addition of the respective strengths of the formwork and concrete.

During the construction phase, the metal formwork must support the sum of the weight of concrete and its own weight without ruin or excessive deflection, and this is done or not with provisional struts arranged at regular intervals between them. retaining walls of the floor.

In addition, after the removal of any temporary struts and during the use phase of the floor, referred to as the mixed phase, the floor must not sag too much under normal conditions of use.

These construction requirements effectively limit the current reach of mixed steel-concrete floors to approximately 5 meters. Indeed, the range of the floor being proportional to its thickness, the addition of concrete proves necessary to increase the thickness of the floor and thus its range. But the metal formwork can not support this addition. To increase the range of mixed steel-concrete floors, it is known from US5,205,098 to increase the structural strength of the formwork by combining two metal profiles arranged head to tail and fixed to each other by their soles. Unfortunately, such a solution significantly increases the thickness of the floor and the presence of the lower profile makes it difficult to place the formwork on the structure of the building.

It is also known from US 4,697,399 to close the wave troughs of ribbed sheets used as formwork to avoid filling them with concrete. This solution makes it possible to increase the height of the wave troughs so as to increase the resistance of the floor without increasing the quantity of concrete required. It is then possible either to increase the range of the floor or to minimize the thickness of the concrete located above the wave troughs. Unfortunately, such a solution is not feasible to reach long spans, for which the combined presence of concrete and reinforcing reinforcing bars in the wave troughs is necessary to ensure the tensile strength of the floor.

The present invention aims to overcome the aforementioned problems by providing a formwork to minimize the amount of concrete necessary while maintaining a mechanical strength of the mixed floor sufficient to increase its range beyond 8 meters.

For this purpose, the invention is primarily a formwork for mixed steel-concrete floor comprising:

a self-supporting profile comprising at least one upper central zone, lateral webs extending the upper central zone on either side of the latter and towards the bottom and at least two lower soles extending the lateral webs,

a spacer profile comprising at least one upper plate and two lateral wings extending the upper plate on either side of the latter and towards the bottom, the spacer profile being disposed at least by the end of the side wings on the self-supporting profile so as to cover at least partially the upper central region and thus form at least one box.

The formwork according to the invention may also include the following optional features, taken alone or in combination:

- The spacer profile covers the entirety of said upper central range;

the lateral webs are inclined towards the outside of the upper central zone;

each of the lateral webs comprises a longitudinal stiffener consisting of two folds forming a recess of the lateral web;

the lateral wings are inclined towards the outside of the upper plate;

- The end of the lateral wings has a raised edge;

- The raised edge is supported on the longitudinal stiffener, the spacer profile and the self-supporting profile being secured by seaming through fasteners regularly distributed over the length of the raised edge;

- The end of the lateral wings comprises a Z-shaped recess;

- The recess is supported on the ends of the upper central range;

- The self-supporting profile includes two upper central areas;

- The self-supporting profile covers at least partially the two upper central areas;

A second object of the invention is constituted by a method of manufacturing a formwork for a composite steel-concrete floor comprising the steps according to which:

a free-standing profile comprising at least one upper central zone is provided, lateral webs extending the central zone on either side of the latter and towards the bottom and at least two lower flanges extending the lateral webs, - Providing a spacer section comprising at least one upper plate and two lateral wings extending the upper plate on either side of it and towards the bottom,

at least the end of the lateral wings of the spacer profile is arranged on the self-supporting profile so as to at least partially cover the upper central zone and thus form at least one box,

- The self-supporting profile and the spacer profile are secured by means of fasteners located along the end of the lateral wings.

A third object of the invention is constituted by a kit for manufacturing a formwork for a composite steel-concrete floor comprising:

at least one self-supporting profile comprising at least one upper central zone, lateral webs extending the central zone on either side of the latter and towards the bottom and at least two lower flanges extending the lateral webs,

- At least one spacer profile comprising at least one upper plate and two lateral wings extending the upper plate on either side of it and towards the bottom.

A fourth object of the invention is constituted by a composite steel-concrete floor comprising at least one formwork according to the invention and a concrete slab cast on the formwork.

A fifth object of the invention is constituted by a method of manufacturing a composite steel-concrete floor of a building comprising the steps according to which:

self-supporting profiles comprising at least one upper central zone are provided, lateral webs extending the central zone on either side of the latter and towards the bottom and at least two lower flanges extending the lateral webs,

provision is made for spacer profiles comprising at least one upper plate and two lateral wings extending the upper plate on either side of the latter and towards the bottom, the self-supporting profiles are juxtaposed on a structure of the building,

at least the end of the lateral wings of the spacer profiles are arranged on at least some of the self-supporting profiles so as to cover at least partially at least one of the upper central regions and thus to form at least one box,

each of the self-supporting profiles is secured to the spacer profile on which it is arranged by means of fasteners located along the end of the lateral wings, so as to form a formwork,

reinforcement reinforcing bars are arranged in wave recesses formed by the lateral webs of two successive self-supporting profiles,

- Liquid concrete is poured over the entire surface formed by the formwork and the self-supporting profiles.

Other characteristics and advantages of the invention will appear on reading the description which follows.

The invention will be better understood on reading the description which follows, given for explanatory but non-limiting purposes, with reference to the appended figures which represent:

FIG. 1 represents a cross-section of a first example of formwork according to the invention,

FIG. 2 represents a cross-section of a second example of formwork according to the invention,

- Figure 3 shows a broken view of a mixed steel-concrete floor according to the invention.

The same reference numbers represent the same elements in each of the figures.

In the context of the invention, the various components of the formwork are preferably made of metal such as bare steel or galvanized with a zinc alloy. Optionally, the steel, galvanized or not, will be covered with a layer of paint to better protect it from corrosion. At least one of the constituent elements of the formwork, and in particular the profile spacer, may however be plastic or any other material sufficiently resistant to the use for which the element is intended.

An example of formwork according to the invention is described with reference to FIG.

1.

In the first place, the formwork 1 comprises a self-supporting profile 2. By self-supporting profile, is meant a shaped sheet so that the simple rigidity of this form ensures its stability and allows its implementation on the structure of the building under construction. through its ends. The shapes that can take this self-supporting profile are known per se. Preferably, one will choose a form for the manufacture of an additive floor. In general, the self-supporting profile comprises at least one horizontal upper central zone 3 extending in the longitudinal direction of the self-supporting profile, two lateral webs 4 and 4 'extending the upper central zone 3 on either side thereof and towards the bottom and at least two horizontal lower flanges 5 and 5 'extending the lateral webs.

In the case of this example, the upper central zone 3 furthermore comprises two longitudinal ribs 6 and 6 'separated by a transverse notch 7. This conformation increases the rigidity of the upper central zone 3 and thus makes possible the circulation of the workers on this area.

In the case of this example, the lateral webs 4 and 4 'are inclined, extending towards the bottom and towards the outside of the upper central area. Alternatively, they can extend vertically or inward, depending on the desired rigidity of the self-supporting profile. Each lateral core of this example also comprises a longitudinal stiffener 8, 8 'consisting of two folds forming a slight recess in the part of the lateral core subjected to compression forces during the mixed phase. This longitudinal stiffener, on the one hand, improves the mechanical behavior of the self-supporting profile and, on the other hand, promotes the establishment of a spacer profile as will be seen later. Alternatively or in addition, the lateral webs 4 and 4 'may have concrete anchoring zones such as bosses or notches located in the part of the lateral web subjected to tensile stresses. In the case of this example, the lower flanges 5 and 5 'have a raised edge 9, 9' which acts as a stiffener and facilitates the implementation of the formwork in particular by making the junctions between two adjacent self-supporting profiles more sealed to concrete liquid.

In general, the self-supporting profile has a height of between 150 and 300 mm, the example of Figure 1 having been made with a self-supporting profile of 220 mm high.

Second, the formwork 1 comprises a spacer profile 10. The latter comprises a horizontal top plate 11 extending in the longitudinal direction of the spacer profile and two lateral wings 12, 12 'extending the upper plate 1 on either side from it and towards the bottom.

In the case of this example, the upper plate 11 further comprises a transverse strike 13. This conformation increases the rigidity of the upper plate 11 and thus makes possible the movement of workers on this surface. Alternatively or in addition, the upper plate 11 may have longitudinal ribs or concrete anchoring areas such as bosses or notches.

In the case of this example, the lateral flanges 12, 12 'are inclined, extending towards the bottom and towards the outside of the upper plate 11. Alternatively, they can extend vertically or inwards, depending on the rigidity sought. Each side wing of this example is flat and comprises, at its end, a raised edge 14, 14 'which acts as a stiffener and facilitates the establishment of the spacer profile 0 on the self-supporting profile 2.

As a general rule, the spacer profile has a height of between 80 and 250 mm, the example of FIG. 1 having been made with a spacer profile 150 mm high.

The width of the upper plate 11, the angle of inclination of the lateral wings 12, 12 'relative to the upper plate 11 and the length of the lateral wings are adjusted so that the spacer profile 10 can be arranged by the end of its lateral wings 12, 12 'on the self-supporting profile 2 so as to cover at least partially its upper central zone 3 while providing a box 15 between the latter and the upper plate 11 of the spacer profile 10.

In the case of this example, the raised edge 14 (respectively 14 ') of the lateral flange of the spacer profile is fitted on the self-supporting profile and bears on the longitudinal stiffener 8 (8' respectively) thereof. The two sections are secured preferably by seaming, preferably via fasteners 16, such as for example screws or rivets, evenly distributed along the length of the raised edge 14, 14 '.

As a general rule, the number of fasteners is limited to shorten the floor's manufacturing time. The seam is then not sufficient for the spacer profile to participate in the mechanical strength of the entire mixed floor. The spacer profile is in this case to formwork lost. However, it is advantageous to improve the mechanical strength of the floor by multiplying the number of fasteners, which however lengthens the manufacturing time of the floor. A compromise is therefore to be found between the desired mechanical resistance of the floor and the time spent seaming the spacer profile to the self-supporting profile. The seaming can be done on site or alternatively in the factory before delivery of the formwork on site.

In the case of this example, the box 15 is left empty. Alternatively, it may be filled with thermal and / or acoustic insulation and / or accommodate the electrical networks and / or fluid networks of the building under construction.

A second example of formwork according to the invention will now be described with reference to FIG. 2. This second example shows all the features of the example described with reference to FIG. 1, with the exception of the differences mentioned below.

This second formwork 1 differs formwork illustrated in Figure 1 mainly in that the self-supporting profile 2 comprises two upper central areas 3 and in that the spacer profile 0 covers them.

In the case of this example, the upper plate 11 comprises a transverse notch 13 and longitudinal ribs 17, 17 'acting as stiffeners. The lateral wings 12, 12 'are inclined, extending towards the bottom and towards the outside of the upper plate 11. Each lateral wing of this example comprises longitudinal stiffeners 18, 18 'consisting of folds forming a slight recess in the side wing. The end of each lateral wing is formed of a recess 19, 19 'Z-shaped which acts as a stiffener and facilitates the establishment of the spacer profile 10 on the self-supporting profile 2.

In the case of this example, the recess 19 (respectively 9 ') of the end of the lateral flange abuts on the end 20 of the first upper central strip of the self-supporting profile 2 (respectively on the end 20' from the second upper central range). The two sections are secured by seaming, preferably via fasteners 16, such as for example screws or rivets, regularly distributed over the length of the recess 19, 19 '.

In addition to the examples illustrated in FIGS. 1 and 2, it will be noted that the mode of engagement of the spacer profile on the self-supporting profiled section via the recess 19, 19 ', as illustrated in FIG. in the example of Figure 1 instead of the nesting mode through the raised edge 14, 14 'and vice versa. It will also be noted that the spacer profile can take various forms. Its upper plate may for example have ribs such that several boxes 15 are formed between the spacer profile and the self-supporting profile.

The spacer profile may also have lateral wings whose lower part has a profile identical to that of the lateral webs of the self-supporting profile so that the interlocking of the spacer profile on the self-supporting profile is made over the entire height of the lateral wing and not only by its end. Such a configuration facilitates the implementation of the spacer profile.

The composite steel-concrete floor is made by the juxtaposition of formwork 1 on the structure 21 of the building under construction as shown in FIG. 3. Depending on the concrete lining desired, the formwork 1 may be immediately adjacent to each other , as illustrated in FIG. 3, or interposed between self-supporting profiles 2 not provided with a spacer profile 10. Reinforcing reinforcing bars 22 are then placed in the wave cavities 23 formed by the lateral webs of two successive autuportant profiles 2. Liquid concrete is then poured over the entire surface formed by the formwork 1 and any self-supporting profiles 2, so as to form a slab 24.

Preferably, the distance separating the top of the spacer profiles from the surface of the slab will be at least 20 mm in order to ensure the good compressive strength of the slab. However, distances of the order of 50 to 200 mm will be preferred to allow the coating of any anti-cracking reinforcement or to allow the structure which carries the composite floor to work mainly in traction or to increase the fire resistance. .

As is apparent from FIG. 3, the caissons 15 formed by the interlocking of the spacer profiles 10 on the self-supporting profiles 2 make it possible to minimize the quantity of concrete necessary for the formation of the slab. It is thus possible to make floors of greater length.

The presence of the boxes 15 does not alter the mechanical strength of the floor formed. Indeed, only the portion of the slab located above the spacer profiles provides the compressive strength, while the combination of reinforcing reinforcing bars and concrete placed in the wave recesses 23 ensures resistance to compression. traction.

In general, the shape and dimensions of the boxes will be adjusted according to the circumstances in order to obtain the best compromise between the desired mechanical strength and range of the composite floor.

The spacer profile may thus be of width less than the width of the upper central region of the self-supporting profile so that it covers only partially the upper central zone when it is arranged by the end of its lateral wings on the self-supporting profile. . Such a configuration may be suitable when one does not seek to greatly reduce the mixed floor. However, and for the same reasons of lightening of the floor, preference will be given to the configuration for which the spacer profile covers the entirety of at least one upper central range so that one side of the box is formed at least by the entire upper central range (except for the possible support of the recess 19, 9 'on the end 20, 20' of the upper central range). For these same reasons for lightening the floor, the ratio between the height of the spacer profile and the height of the self-supporting profile will preferably vary between 0.35 and 1.

Numerical simulations carried out in particular with the formwork illustrated in FIGS. 1 and 2 have shown that the invention made it possible to reach ranges of 8 meters to more than 12 meters.

This combination of a freestanding profile and a spacer profile has several advantages:

- the use of a spacer profile separate from the self-supporting profile allows the use of existing self-supporting profiles,

the profiles being made from sheet metal coils of limited width (and generally of the order of 1200 to 1500 mm), the use of the separate spacer profile also makes it possible to prevent the formwork from being made from a single profile higher but too narrow, the increase in the height of the lateral soul resulting, in fact, the reduction of the width of the upper central range,

- The use of separate spacer profile avoids an overload of concrete that generates a formwork made of a single profile above. Indeed, the reduction of the width of the upper central range has the effect of bringing the formwork closer to one another, thereby increasing the number of wave recesses, thereby increasing the quantities of concrete necessary for their filling and therefore to increase the overall weight of concrete.

Claims

1) Formwork (1) for a composite steel-concrete floor comprising:

- a self-supporting profile (2) comprising at least one upper central region (3), lateral webs (4, 4 ') extending said upper central region on either side of it and towards the bottom and at least two lower flanges (5, 5 ') extending said lateral webs,

- a spacer profile (10) comprising at least one upper plate (11) and two lateral wings (12, 12 ') extending said upper plate on either side of it and towards the bottom,

said spacer profile being disposed at least by the end of said side wings on said self-supporting profile so as to at least partially cover said upper central region and thus form at least one box (15).

2) formwork (1) according to claim 1 wherein said spacer profile (10) covers the entirety of said upper central region (3).

3) Formwork (1) according to any one of the preceding claims wherein said lateral webs (4, 4 ') are inclined outwardly of said upper central region (3).

4) Formwork (1) according to any preceding claim wherein each of said lateral webs (4, 4 ') comprises a longitudinal stiffener (8, 8') consisting of two folds forming a recess of said side web.

5) formwork (1) according to any one of the preceding claims wherein said lateral wings (12, 12 ') are inclined outwardly of said upper plate (11). 6) Formwork (1) according to any one of the preceding claims wherein said end of the side wings (12, 12 ') has a raised edge (14, 14').

7) formwork (1) according to claims 4 and 6 for which said raised edge (14, 14 ') is supported on said longitudinal stiffener (8, 8'), said spacer profile and said self-supporting profile being secured by seaming by l intermediate fasteners (16) evenly distributed along the length of said raised edge (14, 14 ').

8) Formwork (1) according to any one of claims 1 to 5 for which said end of the lateral wings (12, 12 ') comprises a recess (19, 19') Z-shaped.

9) Formwork (1) according to claim 8 wherein said recess (19, 19 ') is supported on ends (20, 20') of said upper central region.

10) Formwork (1) according to any preceding claim wherein said self-supporting profile (2) comprises two upper central areas (3).

11) Formwork (1) according to claim 10 wherein said self-supporting profile (10) at least partially covers said two upper central regions (3).

12) A method of manufacturing a formwork (1) for a composite steel-concrete floor comprising the steps according to which:

a self-supporting profile (2) comprising at least one upper central zone (3) is provided, lateral webs (4, 4 ') extending said central zone on either side of it and towards the bottom and at least two lower flanges (5, 5 ') extending said lateral webs, - Providing a spacer profile (10) comprising at least one upper plate (1 1) and two lateral wings (12, 12 ') extending said upper plate on either side of it and towards the bottom,

at least the end of said lateral wings (12, 12 ') of the spacer profile is arranged on said self-supporting section (2) so as to cover at least partially said upper central zone and thus to form at least one box (5),

said self-supporting profile and said spacer profile are secured by means of fasteners located along the end of said lateral wings.

13) Kit for manufacturing a formwork (1) for composite steel-concrete floor according to any one of claims 1 to 1 comprising:

at least one self-supporting profile (2) comprising at least one upper central zone (3), lateral webs (4, 4 ') extending said central zone on either side of it and towards the bottom and at least two lower flanges (5, 5 ') extending said lateral webs,

- At least one spacer profile (10) comprising at least one upper plate (1) and two lateral wings (12, 12 ') extending said upper plate on either side thereof and towards the bottom.

14) Steel-concrete composite floor comprising at least one formwork according to any one of claims 1 to 1 1 and a concrete slab (24) cast on said formwork.

15) A method of manufacturing a composite steel-concrete floor of a building comprising the steps of:

self-supporting profiles (2) comprising at least one upper central zone (3) are provided, lateral webs (4, 4 ') extending said central zone on either side of the latter and towards the bottom and at least two lower flanges (5, 5 ') extending said lateral webs, - Spreading profiles (10) are provided comprising at least one upper plate (11) and two lateral wings (12, 12 ') extending said upper plate on either side of it and towards the bottom,

said self-supporting profiles are juxtaposed on a structure (21) of said building,

at least one end of said lateral flanges (12, 12 ') is provided with at least some of said self-supporting profiles so as to cover at least partially at least one of said upper central regions and thus to form at least one box ( 5)

each of said self-supporting profiles is secured to said spacer profile on which it is arranged by means of fasteners situated along the end of said lateral wings, so as to form a formwork (1),

reinforcement reinforcing bars (22) are arranged in wave recesses (23) formed by said lateral webs of two successive self-supporting profiles,

- Pouring liquid concrete over the entire surface formed by said formwork and said self-supporting profiles.