FR2575778A1 - Prefabricated construction element and method for building an isothermal wall - Google Patents

Abstract

The invention relates to a prefabricated construction element 1 of the type comprising a central core made of insulating material and facing modules located on either side. The central core comprises two blocks 5 and 6 facing each other and tie plates 7, 8 joining these blocks. The two facing modules 3, 4 are load-bearing and made of a conventional hard material (concrete, baked clay, stone, etc.). The central core and the facing modules are arranged in such a way that, during laying, the superposed construction elements rest on top of each other by means of the blocks 5, 6 of the central core and that a gap is maintained between the upper and lower edges of the facing modules.

Description

PREFABRICATED CONSTRUCTION ELEMENT
AND METHOD FOR THE PRODUCTION OF AN ISOTHERMAL WALL
The invention relates to prefabricated building elements, common blocks or corner blocks, and extends to a method of constructing buildings from such elements; it applies in all cases where it is desired to obtain constructions benefiting from good thermal and sound insulation.

There are numerous isothermal building blocks which are placed, row after row, so as to reproduce, as closely as possible, the traditional methods of laying blocks. Generally, these blocks make it possible to obtain good qualities of thermal insulation, which constitute the essential objective sought during their design; however, they all have certain faults, which can add up for certain blocks, and in particular:
(1) a relatively high cost, in particular from labor costs or the investments required to manufacture them,
(2) laying which requires more labor or deviates from that of traditional blocks and discards masons,
(3) difficulties in obtaining good flatness of the vertical faces or of the upper rows of the walls,
(4) a non-traditional finished appearance, which does not get the favor of customers,
(5) poor protection of the elements from the front, either due to poor attachment of the plaster projected after installation, or from the structure of the blocks when the plaster is integrated into the prefabrication,
(6) finally, unsatisfactory resistance qualities originating either from the structure of the blocks themselves, or from the poor overall cohesion of the latter when the wall is mounted, or from a poorly adapted load transfer between elements.

 Thus, certain construction elements available on the market consist of a block of dense polystyrene foam which is coated on its faces during the prefabrication of a thin layer of expanded clay; the foam block preserves internal voids for pouring filling concrete when the elements are laid. These blocks, almost entirely of polystyrene foam, give excellent qualities of insulation and satisfy the requirements (1), (2) and (3) mentioned above; on the other hand, they have the defects (4), (5) and (6) and, in particular, the qualities of cohesion and mechanical resistance of the finished wall are unsatisfactory.

 Other elements include an internal blade of polystyrene foam on one side of which is mechanically hooked a honeycombed concrete plate, by means of hooking pins which hold said plate apart from the insulating blade; on the other side of this blade is fixed a layer of wood fiber. These blocks are laid dry, by resting the concrete plate and the foam blade of the superimposed blocks; filler concrete is then poured into the empty spaces separating each insulating strip and each concrete plate, then a plaster is sprayed on the vertical faces. These blocks have good thermal insulation qualities, but (at equal thickness) less than those of the block mentioned above due to the presence of a simple lamez of insulator and thermal bridges existing at the level of the studs which penetrate deep into the thickness of said blade. In addition, their cost is very high, mainly due to their complex structure and the cost of the elements that compose them. In addition, during dry laying, it is difficult to obtain a good positioning of the blocks, since the support of the superimposed blocks is effected on one side by contact with dimensionally imprecise concrete slabs.

In addition, the hanging of the plaster projected after assembly is not satisfactory and the insufficient joint between elements does not allow a satisfactory load transfer.

The present invention proposes to provide an improved building element, which combines the essential ntial itities so, jhitées nour such an element / and phmic / - thermal insulation qualities comparable to those of the most efficient blocks in this respect,
- low manufacturing cost requiring reduced labor and investment,
- ease of installation with automatic obtaining of a very precise positioning of the elements and excellent flatness,
- finished appearance similar to that of traditional block walls,
- extremely resistant hooking of external plasters,
- remarkable qualities of resistance and cohesion of the walls obtained.

 We can understand the difficulties of designing an element which combines all of these qualities, while benefiting from a low cost (which must necessarily translate into great structural simplicity).

 (To facilitate understanding, the terms used below which relate to a direction or an orientation, suppose each element in the position where it is when it is posed to make a wall).

The element targeted by the invention comprises a central core of insulating material and facing modules located on either side of said core; according to the present invention, these elements have, in combination, the following characteristics
(a) the core of insulating material comprises, on the one hand, two facing blocks preserving between them an empty volume for a filling material, on the other hand, at least one spacer bar joining said facing blocks,
(b) the two facing modules are load-bearing and made of a traditional hard material, in particular concrete, terracotta, stone, and are fixed on either side of the core on the external faces of the two blocks of the latter,
(c) the blocks of the insulating core have upper and lower faces of conjugate shapes, capable of coming to be positioned in abutment when the building elements are superimposed,
(d) the facing modules have a height less than that of the blocks of the insulating core so as to preserve a gap between the upper and lower edges of the modules of two superimposed construction elements,
(E) the insulating core is made so as to have an appropriate mechanical strength to be able to serve as a temporary support during the superimposition-of construction elements.

 The building element having the above-mentioned characteristics can be adapted to constitute a common building block. In this case, the empty volume separating the two blocks from the core opens laterally on both sides, while the facing modules extend substantially over the entire length of the blocks of said core.

 The building element can also be adapted to constitute a corner block. In this case, the empty volume separating the two blocks from the core opens laterally on one side only and is closed on the other side by an insulating wall joining the two blocks of the core, the wall itself forming part of the insulating core; an additional facing module is in this case fixed on the external face of this insulating wall; one of the facing modules already mentioned (attached to one of the core blocks) extends over the entire length of the element, while the facing module attached to the other block of the insulating core extends on only a fraction of the length of this block so as to preserve on the side of the insulating wall, a bare part -N- adapted to attach a common element of construction in an orthogonal direction.

 Thus, the construction elements in accordance with the invention, both current blocks and corner blocks, are placed in superimposed rows, by pressing them one on the other by the upper and lower edges of the blocks of their insulating core. . This core which can be molded in one piece, in particular from dense polystyrene foam, benefits from high dimensional precision so that the positioning of the blocks is precise, the flatness of the vertical faces and of the rows being excellent. During installation, the cores made to present an appropriate mechanical resistance serve as temporary support for the elements.

Filling concrete is then poured into the communicating empty volumes, delimited by the cores of the elements of the various rows. Finally, the faces of the facing modules are plastered, with plaster injection between the upper and lower edges of said modules.

 The thermal insulation qualities of the walls thus produced are remarkable because of the double-insulating structure of the core and the absence of a thermal bridge.

 The cladding modules are preferably constituted by concrete hollow wafers and / or terracotta hollow briquettes. The honeycombed nature of these modules further supports the insulation qualities obtained; in addition, such modules are, as such, available on the market at appropriate dimensions (thickness of the order of 5 cm), so that the manufacture of the element according to the invention can be carried out without specific investment for the production of said modules, the only investment required consists of the molds for producing the core. In practice, the facing modules will be glued to the faces of the core, so that the manufacturing of the element is reduced to a simple and rapid operation.

The manufactured wall has remarkable qualities of mechanical resistance, mainly originating
- the good cohesion of the elements, conferred by the filling concrete which provides an overall connection of the superimposed or contiguous elements (due to the wide communication of the empty volumes filled with concrete after laying),
- good load transfer taking place at the facing modules through the joint injected between modules,
- the structure with three resistant thicknesses of the finished wall (central filling concrete and facing modules located on either side).

 In addition, the plaster which penetrates between the elements over the entire thickness of the facing modules present, of the ribbed profile type which considerably increases its adhesion and its mechanical properties.

 It should be noted that the execution of the joint during the plastering makes it possible to significantly lower the cost price of the construction due to the significant gain in labor thus achieved during installation. Of course, the user of the construction elements in accordance with the invention retains the option of making the joint in a conventional manner when the elements are installed (in particular if it is not equipped with a projection apparatus for plaster).

In this case, a joint guide for the placement of the mortar can be used to facilitate the implementation.

Other characteristics, objects and advantages of the invention will emerge from the description which follows with reference to the appended drawings, which present by way of nonlimiting example an embodiment; on these drawings which form an integral part of the present description
FIG. 1 is a perspective view of a current block in accordance with the invention,
FIG. 2 is a cross section thereof through a vertical plane A,
FIG. 3 is a section through a horizontal plane B thereof,
FIG. 4 is a perspective view of a corner block according to the invention,
FIG. 5 is a schematic perspective view, illustrating the mounting of the elements,
FIG. 6 is a partial cross section of the finished wall, by a vertical plane,
FIG. 7 is a partial cross section of said wall, on a horizontal plane,
FIG. 8 illustrates, in longitudinal vertical section, an alternative embodiment of the wall,
FIG. 9 is a section thereof, on a larger scale, by a transverse vertical plane,
FIG. 10 is a perspective view of an accessory used in the above-mentioned variant,
- Figure 11 is a section of another variant, by a longitudinal vertical plane.

 The current block 1 represented by way of example in FIGS. 1, 2 and 3 is part of a rectangular piped parallel, the dimensions given by way of illustration are approximately as follows: length 500 mm, height 200 mm, thickness 300 mm; this block essentially comprises three constituent parts: a central insulating core 2 and two facing modules 3 and 4 located on either side of this core.

 The core 2 is made in one piece by molding in expanded polystyrene foam with a density between 25 and 40 kg / m3, in particular equal to 30 kg / m3.

 This insulating core is formed by two insulating blocks 5 and 6 located opposite and joined by two spacer bars 7 and 8. Each insulating block 5 or 6 is inscribed in a rectangular parallelepiped whose dimensions given by way of illustration are approximately as follows: length 505 mm, height 205 mm, thickness 40 mm. The two insulating blocks 5 and 6 are kept apart from one another by the spacer bars, by a distance of the order of 120 mm.

 The two bars 7 and 8 have an oblong shape as shown, in order to facilitate the pouring of the filling material into the empty volume between blocks 5 and 6. These bars have a height of the order of 120 mm and a length (dimension - taken in the longitudinal direction of the block) of the order of 60 mm; taking into account the density of the polystyrene used, these bars thus have sufficient strength to ensure a good connection between the insulating blocks 5 and 6, without risk of deformation during the temporary assembly phase.

 In addition, each bar is offset towards the inside of the element with respect to the lateral edges of the insulating blocks 5 and 6 so as to completely release the two sides of the element which open laterally as shown in the figures; the height and the length of each strip 7 or 8 being much less than the height and length of the insulating blocks 5 and 6, this arrangement preserves between the blocks 5 and 6 an open empty volume which will make it possible to pour a filling concrete capable of ensuring a overall cohesion between the elements, without isolated chimneys or canals, with the option of adding vertical reinforcements extending between the bars or horizontal reinforcements extending above and below them along rows of blocks.

 Preferably, as illustrated in FIG. 3, each spacer bar 7 or 8 has a median axis b1 or b2 distant from the nearest lateral edge by a distance -d- substantially equal to a quarter of the length of the block; in other words, the median axis b1 or b2 of each bar is located halfway between the axis of symmetry X of the block and the neighboring lateral edge. This arrangement ensures a superposition of the bars of the current blocks when they are mounted with crossed joints with an offset corresponding to a half-block: as will be seen below, it is thus possible to pour posts between certain bars.

 In addition, each insulating block 5 or 6 has a male interlocking structure such as 5a or 6a extending along its upper edge, a combined female limping structure such as 5b or 6b extending along its lower edge, a male interlocking structure such as 5c and 6c extending along one of its lateral vertical edges and a combined female interlocking structure such as 5d or 6d extending along its other edge vertical lateral.

 In the example, these structures are of trapezoidal section, projecting or hollow, so as to ensure automatic and precise positioning at the end of embolism.

 The facing modules 3 or 4 are, in the example, constituted by blister boards of agglomerated concrete of a type existing on the market. These plates produced by molding have several blind cells (in particular five in number) which lead to the lower edges of said plates. The height of these plates is less than that of the insulating blocks 5 and 6, while their length is slightly less than that of said blocks so as to be able to extend substantially over the entire length of the external faces thereof.

Such plates have in particular the following dimensions: length 500 mm, height
195 mm, thickness 50 mm. The upper edge 3a of these plates
tes is smooth, however their vertical side edges generally have a half-moon groove such as 3d.

 The plates 3 and 4 can also be formed by honeycomb briquettes or by stone facings of comparable dimensions.

 The plates 3 and 4 are glued to the faces of the insulating blocks 5 and 6 so that their upper edges 3a are set back -r- below the level of the upper edges of the insulating blocks 5 and 6 (bottling structures not taken into account), and that their lower edges 3b are located substantially at the same level as the lower edges of said blocks.

 In the example of the dimensions provided, the shrinkage -r- is of the order of r = 10 m, so that between two building blocks superimposed by the support of their insulating blocks there appears a gap of approximately 10 mm between the edges upper and lower facing plates.

In addition, platelets 3 and 4 are
glued so that their side edges coincide with
those of insulating blocks 5 and 6 (embolism structures and
gorges not taken into account).

 Bonding can in particular be carried out with a cement-based glue and hydraulic lime.

 In addition, short connecting reinforcements such as 9 are arranged through the insulating blocks 5 and 6 at the parts of said blocks located in projection relative to the facing plates 3 and 4. These reinforcements protrude, on one side, au- above the plates in the vicinity of the edges 3a thereof and, on the other side, in the empty volume delimited between insulating blocks; each frame 9 has a bent or looped hooking end. These reinforcements which are two in number per current building block (in the example shown) are very easily put in place, splitting the polystyrene at their level.

 Furthermore, the invention extends to a corner block 10 as shown in Figure 4; this block is produced according to principles similar to those described above and has the same overall dimensions.

 I1 differs from the current block in that it opens laterally only on one side and is closed on the other side by an insulating wall 11; this wall which is part of the insulating core unites the two insulating blocks 5 'and 6' thereof and replaces one of the bars (a single bar 7 'therefore remaining in the corner block). An additional facing module 12 is fixed by bonding to the external face of said insulating wall 11; this facing module consists of a blister card. of the same type as before, but the length of which is 200 mm so as to correspond to the thickness of the insulating core. The facing module 4 '(corresponding to the outside of the anqle) has a substantially long length! time of 500 min to extend / over the entire length of the element (including additional facing 12). The other 3 'facing module (corresponding to the interior of the angle) has a length of 200 mm and extends over a fraction of the element (open side) so as to preserve the side of the insulating wall. 11, a bare part -N- of 300 mm in length, adapted to attach a current element by one of its side edges.

 The other provisions provided on the current block are found in a similar form in the corner block: 9 'connecting frames (note that a third frame is provided on the wall 11), interlocking structures (the structures of the lateral vertical edges 5 ′, 6 ′ are female structures, conjugated with the male structures of the current blocks and provided only on the open side), upper edge of the plates 3 ', 4', 12 recessed -r- by relative to the upper edge of the insulating blocks 5 ', 6' and insulating wall 11, arrangement of the spacer bar 7 ', ...

/ also
The corner block 10 can be used to make the opening tables in the absence of a pre-frame.

Figure 5 illustrates the mounting of a
building wall including an angle. Current blocks 1 or
10 corner blocks are overlapped with cross joints with a
offset corresponding to half a block, as shown in this
figure. These blocks are supported by their insulating blocks
5, 6 (and insulating wall 11 for the corner block)
which therefore act as temporary support means for
elements; the dimensional accuracy of these insulating blocks
combined with the presence of interlocking structures ensures precise and automatic positioning of the building blocks. In this way, perfectly flat and vertical wall faces and superimposed rows of remarkable flatness are obtained.

Then injected into the empty volumes between insulating blocks, a bonding concrete which can be, depending on the application, a heavy load-bearing concrete, a concrete
light insulator (eg concrete glass beads) or
semi-light concrete (examples: expanded clay concrete or
expanded concrete). This concrete is distributed throughout the empty volume
of the wall and forms a coherent mass which ensures excellent cohesion between blocks of the same row and between blocks of superimposed rows. Armatures can be placed vertically or horizontally between the spacer bars.

During this casting operation, the
short reinforcements 9 are partially embedded in the filling concrete.

A plaster is then projected onto the
sides of the wall so as to bring it into the spaces -E- (height of about 10 mm) between facing plates (Figure 6). The facing part of the wall is thus secured to the central friend thereof by the reinforcements 9. The plaster thus ribbed and reinforced by the reinforcements 9 which connect it to the filling concrete, is particularly resistant and adherent.

It should be noted, as shown by
FIGS. 6 and 7, that the seals, both vertical and horizontal, are interrupted without risk of the appearance of thermal bridges thanks to the shifts introduced by the embedding structures.

The walls produced have a double
insulation, further improved by platelet cells
its mechanical characteristics from the three layers
load-bearing, good overall cohesion, load transfer
correct in terms of siding and excellent resistance
of plaster are remarkable.

Furthermore, Figures e, 9 and 10
illustrate another embodiment of the wall.

When stacking neck blocks
rants, their spacer bars are arranged vertically to each other; some are fitted, as the assembly progresses, with accessory parts 13 made of insulating material (expanded polystyrene). These parts 13 have the shape shown in FIG. 10 to overlap each bar and seal the vertical spaces between two adjacent superimposed bars. This produces closed vertical formwork such as C, as illustrated in the figure.

 The empty volumes remaining from the cores (excluding formwork C) are filled with an insulating material in bulk V, such as glass beads or the like, or may remain empty.

Formwork C is filled with concrete after the installation of reinforcements to form reinforced concrete posts; also reinforced horizontal beams P can be simultaneously cast over the insulating material
V (serving as the bottom of the formwork) to connect the posts.

 As illustrated in Figure 11? the parts 13 can, if necessary, be replaced by the placing against the bars, of light formwork such as strips of cardboard 14. In this case, the posts are first poured, then the loose insulating material is put in place in the remaining empty volumes, the horizontal beam then being cast.

 This gives a grid of beams and load-bearing posts, the mesh of which is filled with loose insulation; these provisions, combined with the other characteristics of the wall, contribute to providing excellent qualities of mechanical resistance and remarkable qualities of insulation, while benefiting from a simple and rapid implementation.

 Of course, the invention is not limited to the terms of the above description, but on the contrary includes all variants. Thus, the facing modules can be made of another known carrier material: stone, plaster-based material, etc.

Claims (16)

 1 / - Prefabricated building element, comprising a central core made of insulating material and facing modules located on either side of said core, and combining the following characteristics:  (a) the core of insulating material (2) comprises, on the one hand two facing blocks (5, 6) preserving between them an empty volume for a filling material, on the other hand, at least one spacer bar 7, 8) bringing together said facing blocks,  (b) the two facing modules (3, 4) are load-bearing and made of a traditional hard material, in particular concrete, terracotta, stone, and are fixed on either side of the core (2) on the external faces of the two blocks (5, 6) of the latter,  (c) the blocks (5, 6) of the insulating core have upper (5a, 6a) and lower (5b, 6b) faces of conjugate shapes, able to come to rest while the building elements are superimposed,  (d) the facing modules (3, 4) have a height less than that of the blocks (5, 6) of the insulating core so as to preserve a gap between the upper and lower edges of the modules of two superimposed construction elements,  (E) the insulating core (2) is made so as to have an appropriate mechanical strength to be able to serve as a temporary support during the superposition of construction elements.  2 / - Prefabricated element according to claim 1, called to constitute a common building block (1), characterized in that the empty volume between the two blocks (5, 6) of the insulating core opens laterally on both sides , the facing modules (3, 4) extend substantially over the entire length of the blocks (5, 6) of the insulating core.  3 / - Current building block according to claim 2, characterized in that each block (5, 6) of the insulating core has on a verti cal lateral edge (5c, 6c), a male embellishment structure projecting relative to the module facing (3, 4) and, on the opposite side edge (5d, 6d), a female embedding structure combined.  4 / - Current building block according to one of claims 2 or 3, characterized in that it comprises two spacer bars whose median axes (bl, b2) are distant from the side edges of a distance (d) substantially equal a quarter of the length of the block, so that the bars of overlapping blocks with crossed joints (with pn offset corresponding to a half-block) are located directly above each other.  ie facing module (3 ') fixed on the other block (5') of the insulating core extends over only a fraction of the length of this block so as to preserve on the side of the insulating wall (11), a part nude (N) adapted to attach a common construction element in an orthogonal direction.  the facing module (4 ′) fixed to one of the blocks (6 ′) of the insulating core extends substantially over the entire length of the element,  an additional facing module (12) is fixed to the external face of said insulating wall,  the empty volume between the two blocks of the insulating core opens laterally on one side only and is closed on the other side by an insulating wall (11) joining the two blockades,  5 / - Prefabricated element according to claim 1, called to constitute a corner block (10), characterized in that  6 / - Corner block according to claim 5, characterized in that each block of the insulating core has, on its vertical lateral edge located on the open side, a female embolism structure, combined with the male structures of the current blocks.  7 / - Prefabricated building element according to one of claims 1, 2, 3, 4, 5 or 6, characterized in that the facing modules (3, 4) have upper edges set back (r) at below the level of the upper edges of the blocks (5, 6) of the insulating core, and of the lower edges substantially at the same level as the upper edges of said blocks.  8 / - Prefabricated building element according to one of claims 1, 2, 3, 4, 5, 6 or 7, characterized in that connecting reinforcements (9) are arranged through the blocks (5, 6) of the insulating core at the level of the parts of said blocks projecting relative to the facing modules (3, 4), said reinforcements projecting, on one side, into the empty volume between blocks, and, on the other side, in the vicinity of edges of facing modules.  9 / - Prefabricated building element according to one of claims 1, 2, 3, 4, 5, 6, 7 or 8, wherein the upper and lower edges of the blocks of the insulating core have male or female nesting structures (5a, 6a; 5b, 6b).  10 / -Prefabricated building element according to one of claims 1, 2, 3, 4, 5, 6, 7, 8 or 9, in which each spacer bar (7, 8) of the insulating core has a height and a length lower than the height and length of the blocks (5, 6) of said core and is offset towards the inside of the element with respect to the lateral edges of said blocks.  11 / - Prefabricated building element according to one of the preceding claims, in which  the insulating core (2) is molded in one piece from polystyrene foam with a density between 25 kg / m3 and 40 kg / m3,  the facing modules (3, 4) are formed by concrete hollow wafers and / or terracotta hollow briquettes,  said facing modules are bonded to the faces of the blocks (5, 6) of the insulating core (or face of the insulating wall 11).  12 / - Method of construction of an insulated building wall from prefabricated elements according to one of the preceding claims, consisting. placing the elements (1, 10) in superimposed rows by pressing them one on the other by the upper and lower edges of the blocks (5, 6) of their insulating core,  to have a filling material in the communicating empty volumes, delimited by the insulating cores of the elements of the various rows,  plastering the faces of the facing modules (3, 4) with plaster injection between the upper and lower edges of said facing modules.  13 / - Method according to claim 12, in which the filling material is a bonding concrete poured into all of the empty volumes of the insulating cores.  14 / - Method according to claim 12, in which the blocks used are blocks in accordance with claim 4, arranged with crossed joints with an offset corresponding to a half-block, characterized in that the placing of the filling material consists , on the one hand, by pouring concrete between predetermined spacer bars in order to constitute posts, on the other hand, by filling the remaining volumes with an insulating material in bulk (V).  15 / - Method according to claim 14, characterized in that, when the elements are superimposed, the spacer bars contiguous to the pouring posts are equipped with accessory parts (13) closing off the vertical spaces between them in order to form formwork vertical (C) for said posts.  16 / - Method according to one of claims 14 or 15, characterized in that the establishment of the filling material also consists of a casting of horizontal beams (P) above the insulating material in bulk in order to connect the posts.