FR2676081A1 - ISOTHERMAL BANK FOR CONCRETE FORMWORK. - Google Patents

Abstract

The invention relates to an isothermal shuttering for concrete formwork intended in particular for the building industry for the construction of massive elements. The isothermal panel (1) is formed from a shuttering sheet (2) and a rear sheet (3) between which is placed an insulating material (4) such as polyurethane foam. According to the invention, the sheet (1) has means for attaching the insulating material (4) to the sheets (2 and 3) uniformly distributed. These hooking means are in the form of grids (5 and 6) embedded in the insulating material (4) and fixed to the sheets (2 and 3). The invention relates to manufacturers of construction equipment.

Description

The invention relates to an insulated formwork for concrete formwork,

  intended in particular for the building industry for the construction of massive elements It mainly concerns builders of construction site equipment. More and more frequently, the building industry is using the cast concrete technique to produce the various building elements. These offer many technical and economic advantages over traditional building materials such as brick and mortar. In particular, the time of implementation on the building sites is reduced which

  saves a lot of labor.

  We mainly know * two techniques for using cast concrete. Firstly, the parts are made in the factory and are sent to the site where they are assembled. For mass production, this is advantageous but finds its limit in the size of the mold. parts Then, we know the technique of pouring fresh concrete on site in formwork to make parts directly. This technique is more widespread because

she is more flexible.

  Originally, wooden formwork was used, but it was gradually replaced by stronger and more resistant metal forms, which were very easy to use because of their modular appearance. These metal forms consist of an assembly of

  shutters that form the retaining walls of poured concrete.

  This technique of pouring concrete in situ already largely developed has been significantly improved with the appearance of isothermal formwork This feature makes it possible to take advantage of the exothermic reaction encountered during the setting of fresh concrete The isothermal formwork avoids that the calories generated by the chemical reaction is dissipated in nature, which causes an increase in the temperature of the mass of concrete, o faster drying and improved properties This acceleration of the drying time is greatly appreciated economically and this has largely contributed to the growth of

insulated formwork.

  Currently, an insulated panel includes a formwork sheet forming the face located on the concrete side and a back sheet forming the outer face Between these sheets is a mattress of insulating material such as a polyurethane foam Preparing correctly the surface of the formwork sheets and back, it is possible to adhere the

  foam on the sheet to form a compact package.

  Unfortunately, in practice, experience shows that very often there is a decohesion between sheets, more

  particularly the formwork sheet, and the insulating foam.

  This occurs in case of strong stress when the surface of the sheet has not been satisfactorily treated before. When there is a break in the connection between the sheet and the foam, there is a loss of property

  insulation and the formwork must be reformed.

  The discovery of this disadvantage has made it possible to implement means to avoid decohesion. The main object of the present invention is to provide a compact and extremely robust isothermal form. In particular, the connection between sheets and insulating material has been neat to be able to withstand the stresses. the most severe It should be emphasized that this mechanical reinforcement takes into account the fragility of the insulating material thanks to a

  general distribution of constraints.

  Of course, the respect of the insulation is completely maintained and it should be emphasized in this respect that the traditional fastening means by bolting, riveting can not be used because of the thermal bridges they

cause.

  The search for an effective means of connection between an insulating material and a sheet has also been oriented in order to save money so as not to handicap the product by

excessive cost.

  Other purposes and advantages of this

  invention will appear during the description that will

  follow which is however given only as an indication.

  The isothermal formwork for concrete formwork, intended in particular for the building industry for the construction of massive elements, formed of a formwork sheet and a rear sheet between which is disposed an insulating material such as a foam of polyurethane, is characterized in that it has means for fastening the insulating material on the formwork sheet. The invention will be better understood when reading

  the following description, accompanied by a drawing in annex:

  FIG. 1 shows schematically in view of cutting the isothermal form of the present invention provided with its means

hooking.

  The present invention relates to an isothermal formwork for concrete formwork, intended in particular for the industry of

  building for the construction of massive elements.

  The building industry is increasingly using molded concrete elements for building construction, mainly because of the mechanical properties of this material and the economic advantage of this technique. is transported to the construction site in tops where it is poured into

  modular metal forms.

  Given the exothermic reaction encountered during the setting of the concrete, it is possible to take advantage of this property to accelerate the drying of the concrete using isothermal formwork For this, the forms of the formwork are made using a formwork sheet inside , an external sheet and a mattress

  of intermediate insulating material.

  Unfortunately, in practical terms, it is a fragile formwork due to the mere chemical bonding by gluing It is desirable, according to the invention, to add a mechanical fastening in addition to chemical bonding by bonding to relieve the shear stress at the interface The main difficulty is to design the attachment means respecting the thermal insulation, knowing that it must also be compatible with a fragile material such as insulating foam and be economical The main means of attachment Traditional known to those skilled in the art such as screws and bolts for example, can not be used because of the thermal bridges they create and the lack of resistance of the polyurethane foam that offers no solid grip C ' is in this spirit that has been developed the present invention which is intended to distribute

  the stress in the whole of the insulating mass.

  The general construction of a box is well known to those skilled in the art It uses metal materials for their machining property and mechanical strength The back side of the form is generally stiffened by stiffeners, the whole receives stabilizing brackets at the base and comprises fastening means at the periphery At this level, the isothermal form of the present invention is distinguished from the existing boards by the internal fixation of the insulating material on the sheets as shown in Figure 1 which represents an insulated blank (1) for cutting This consists of a formwork sheet (2) which represents the face of the formwork (1) intended to be in contact with the molded concrete, and a rear plate ( 3) which constitutes the outer face of the formwork (1) These sheets are analogous to those traditionally used for the manufacture of insulated covers. The central part of the box contains an insulating material (4), traditionally it is polyurethane foam, however other materials could be perfectly used Polyurethane foam is relatively fragile in that it can not bear important mechanical stresses Nevertheless, it is particularly important that the contact is perpetually ensured between the formwork sheet (2) and the insulating material (4) to give the banche the insulation property and ensure maximum efficiency in its

  resistance to deformation under the pressure of concrete.

  According to the invention, the formwork (1) has means for attaching the insulating material (4) to the formwork sheet (2). These fastening means ensure the fixing and the plating of the insulating foam (4) on the face internal of the formwork sheet (2) In addition, the attachment means provide uniform fixation of the foam (4) over the entire internal surface of the formwork sheet (2) This is particularly important for the distribution of the stresses Indeed, a point fixation even if there are several, locates the stress precisely at these fixings and one may witness tears of the foam due to a disparity of internal forces. According to the present invention, the hooking means are in the form of a grid (5) fixed on the formwork sheet (2) and embedded in the insulating material The grid (5) extends over the entire surface of the

  foam (4) near the formwork sheet (2).

  When filling the polyurethane foam (4), this mesh is embedded in the foam and this bonding completes that resulting from the adhesion of the foam

  on the sheet itself during the manufacturing phase.

  A concrete trellis can be perfectly

used as toasting (5).

  The attachment means are made with a structure and a material allowing the physical and mechanical attachment These attachment means can be realized in

expanded metal.

  Although this is less necessary, it is advantageous to use fastening means to also fix the insulating material (4) on the rear sheet (3). These attachment means will ensure a uniform distribution of the stress within the foam (4). to prevent tearing of the latter In the same way as for the formwork sheet (2), a grid (6) embedded on the entire surface of the foam (4) near the rear sheet (3) will be used to fix said mesh (6) on the sheet

rear (3).

  The use of a wire mesh makes it possible to anchor the formwork and back sheets in the insulating foam and, in this respect, it would also be possible to use perforated sheets or any other structure that respects the mass of foam as a set in which said

structure is prisoner.

  Other implementations of the present invention, within the reach of those skilled in the art, could also be envisaged without departing from the scope thereof.

Claims (6)

REVENDI CATIONS   1 Isothermal formwork for concrete formwork, intended in particular for the building industry for the construction of massive elements, formed of a formwork sheet (2) and a rear sheet (3) between which is disposed an insulating material ( 4) such as a polyurethane foam, characterized in that it has means for fastening the insulating material (4) on the formwork sheet (2). 2 isothermal sleeve, according to claim 1, characterized in that it presents means   hooking of the insulating material (4) on the rear plate (3).   3 isothermal sleeve, according to claim 1 or 2, characterized in that the attachment means provide a uniform distribution of the stresses in the insulating material (4).   4 isothermal sleeve, according to claim 3, characterized in that the means are in the form of a mesh (5 or 6) embedded in the insulating material   (4) and fixed at least on one of the sheets (2 or 3).   Insulated sleeve, according to claim 4, characterized in that the screens (5 or 6) are attached to the sheets (2 and 3).   6 isothermal sleeve, according to claim 4, characterized in that the mesh (5 or 6) is   in the form of a concrete mesh.   7 isothermal sleeve, according to claim 1, characterized in that the attachment means are made with a structure and a material allowing   the physical and mechanical attachment.   Isothermal sleeve, according to claim 1, characterized in that the attachment means are made of expanded metal.