Patent Application
20210131097
The invention lies in the field of the construction of buildings, more particular in the field of construction blocks, notably made of inert material such as concrete.
The published patent document WO 97/25499 A1 discloses a hollow construction block provided, on each of its upper, lower, and lateral faces with reliefs that are able to interlock with one another when several blocks are assembled alongside one another and/or on top of one another. Such blocks can be assembled “dry”, that is to say without the use of mortar. The cavities in the blocks are intended to be filled with cement or mortar in order to stabilize the wall thus constructed. Therefore, such a block is not suitable for exclusively dry construction, that is to say without the addition of cement into the voids. The main reason appears to be that the vertical portions referred to as “tongues”, situated between the plates forming the main faces, fail to ensure sufficiently precise interlocking. Specifically, in the case of a foreign body and/or irregularity at the upper face of one of these vertical portions, the upper block will inevitably exhibit a deviation with respect to the vertical. Such a deviation is likely to destabilize the wall, risking it collapsing, mainly because of the lack of resistance of the blocks to coming apart.
The published patent document WO 2012/160150 A1 likewise discloses a concrete construction block intended for the “dry” construction of walls. To this end, the block comprises, similarly to the previous document, vertical portions forming transverse bosses on the upper face and voids in the lower face. These vertical portions are situated between two plates forming the main faces. These plates likewise comprise, on the edges at the opposite lateral faces of the block, profiles of the tenon/mortice type. However, these profiles are very small in size and can cause problems with regard to manufacturing tolerances, and as regards the assembly thereof when irregularities or other defects are present in these profiles.
The objective of the invention is to remedy at least one of the drawbacks of the abovementioned prior art. More particularly, the objective of the invention is to propose a construction block that allows dry assembly while ensuring sufficient stability, notably for walls of a certain height.
The subject of the invention is a construction block made of inert material, such as concrete, comprising two opposite main faces, an upper face, a lower face, and two opposite lateral faces, the upper and lower faces and the lateral faces having, respectively, complementary reliefs that are able to interlock when several of the blocks are juxtaposed; said block being noteworthy in that the relief of the upper face comprises two tenons extending in parallel and at a distance from the two main faces, respectively, and the relief of the lower face comprises two corresponding slots extending in parallel and at a distance from the two main faces, respectively.
According to one advantageous embodiment of the invention, said block comprises voids and a continuity of material between each of the tenons of the upper face and the corresponding slot of the lower face. The continuity of material advantageously has a thickness at least equal to the thickness of the corresponding tenon, specifically from the tenon to the corresponding slot.
According to one advantageous embodiment of the invention, the voids comprise voids extending vertically between the tenons of the upper face and the corresponding slots of the lower face.
According to one advantageous embodiment of the invention, the voids comprise voids extending vertically between, for the one part, each of the main faces and, for the other part, the adjacent tenon of the upper face and the adjacent corresponding slot of the lower face.
According to one advantageous embodiment of the invention, each of the tenons of the upper face has a thickness of between 10% and 17% of the width of the block.
According to one advantageous embodiment of the invention, each of the tenons of the upper face is at a distance from the adjacent main face of between 20 and 25% of the width of the block.
According to one advantageous embodiment of the invention, each of the upper face and lower face has a generally straight transverse profile on either side of the two tenons of said upper face and the two slots of said lower face, respectively.
Advantageously, the transverse profile of the upper face has a horizontal central part that is vertically set back with respect to the horizontal lateral portions on either side of the tenons. This setback may be greater than or equal to 1 mm.
According to one advantageous embodiment of the invention, each of the tenons of the upper face has a height greater than the thickness of said tenon, and each of the slots of the lower face has a depth greater than the width of said slot.
According to one advantageous embodiment of the invention, the relief of a first of the two opposite lateral faces comprises at least two vertically extending tenons and the relief of the second of the two opposite lateral faces comprises at least two corresponding slots.
According to one advantageous embodiment of the invention, the at least two tenons of the first lateral face comprise a central tenon and two lateral tenons on either side of the central tenon, and the at least two slots of the second lateral face comprise a corresponding central slot and two corresponding lateral slots on either side of the central slot.
According to one advantageous embodiment of the invention, the central tenon of the first lateral face and the corresponding central slot of the second lateral face have a trapezoidal section.
According to one advantageous embodiment of the invention, the central tenon of the first lateral face and the corresponding central slot of the second lateral face are situated transversely between the two tenons of the upper face and between the two slots of the lower face.
According to one advantageous embodiment of the invention, the central tenon of the first lateral face and the corresponding central slot of the second lateral face have a maximum width of between 25% and 30% of the width of the block.
According to one advantageous embodiment of the invention, each of the two lateral tenons of the first lateral face is aligned with the adjacent main face, and each of the two lateral slots of the second lateral face is aligned with the adjacent main face.
According to one advantageous embodiment of the invention, each of the at least two lateral tenons of the first lateral face has a height of between 8% and 15% of the width of the block.
A further subject of the invention is a construction block made of inert material, such as concrete, comprising two opposite main faces, an upper face, a lower face, and two opposite lateral faces, the upper and lower faces and the lateral faces having, respectively, complementary reliefs that are able to interlock when several of the blocks are juxtaposed; said block being noteworthy in that said block comprises one or more levelling layers, on the upper face and/or on the lower face, that have a thickness greater than 5 mm and/or less than 40 mm and are made of a mortar having a Young's modulus less than 4000 MPa and/or a compressive strength less than 6 MPa.
The levelling layer(s) come into contact with the vertically adjacent block so as to ensure load transfer.
According to one advantageous embodiment of the invention, the mortar has a Young's modulus greater than 1000 MPa and/or a compressive strength greater than 1 MPa.
According to one advantageous embodiment of the invention, the mortar comprises a binder, preferably based on cement, and granules, the average diameter of which is less than 50% of the thickness of the corresponding levelling layer.
According to one advantageous embodiment of the invention, the mortar comprises a binder, preferably based on cement, and granules, the average diameter of which is less than 1.5 mm, preferably less than 1 mm.
According to one advantageous embodiment of the invention, the material forming a central part of the block, preferably corresponding to the rest of the block, is a concrete having a Young's modulus greater than 20 000 MPa and/or a compressive strength greater than 20 MPa.
According to one advantageous embodiment of the invention, the levelling layers on the upper face are situated on the tenons and/or laterally, towards the outside, with respect to said tenons.
According to one advantageous embodiment of the invention, the levelling layers on the lower face are situated at the bottom of the slots and/or laterally, towards the outside, with respect to said slots.
According to one advantageous embodiment of the invention, the levelling layer(s) extend(s) along the entire length of the block.
The measures of the invention are advantageous in that they ensure a dry assembly without it being necessary to fill the inside of the blocks with cement, concrete and/or insulation, while having satisfactory stability. The block of the invention thus makes it possible to construct walls of the temporary partition type, that is to say ones that can be dismantled very easily without damage and without any particular effort. The main faces can have a particular surface finish. Following the construction of a wall with the blocks of the invention, said blocks can then be painted on the faces in question.
The presence of at least two tenons on the upper face and, similarly, of two corresponding slots in the lower face makes it possible to ensure a good level of stability, notably for the construction of walls notably with a height of 6 m or more. The tenons and corresponding slots on/in the opposite lateral faces also allow exact adjustment of the blocks. The block of the invention has been the subject of statistical studies as part of a doctoral thesis.
The use of a specific material that is less resistant and/or brittle at the upper face and/or the lower face causes a levelling effect that makes it possible to distribute loads better, notably in the event of misalignment of the blocks once assembled to form a wall or a partition. This levelling effect is particularly advantageous in the context of a dry construction, that is to say one in which there is no layer of assembly mortar in the form of a paste.
The block 2 comprises main faces 4 and 6, which extend longitudinally and parallel to one another. These faces are intended to remain visible after several blocks have been assembled. The block 2 also comprises an upper face 8, a lower face 10 and two opposite lateral faces 12 and 14. Each of the upper face 8, lower face 10 and lateral faces 12 and 14 comprises a relief that is able to cooperate by interlocking with a corresponding face of another, identical block disposed adjacent thereto.
More specifically, the upper face 8 comprises two tenons 16 that extend longitudinally, advantageously continuously between the two lateral faces 12 and 14. The lower face 10 comprises two corresponding slots 16′, which then likewise extend longitudinally and advantageously continuously between the two lateral faces 12 and 14. These slots 16′ are dimensioned so as to receive the tenons 16 of another, identical block supporting the block 2. It is apparent, notably in
With reference to
With reference to
It is also apparent that the two tenons 16 are disposed symmetrically on either side of a longitudinal axis of the block 2 and that each of these tenons is at a distance from the adjacent main face 4 and 6. This distance D may be between 20% and 25% of the width L of the block. For a width L of 175 mm, the distance D may be around 40 mm.
Voids 22 may be provided transversely between the tenons 16, these voids extending vertically through the block, from the upper face 8 to the lower face 10. Similarly, voids 24 may be provided between each of the tenons 16 and the adjacent main face 4 or 6, these voids passing vertically through the block from one side to the other.
The first face 12 of the two lateral faces comprises three vertical tenons, namely a central tenon 18 and two lateral tenons 20. The central tenon 18 advantageously has a trapezoidal section. It extends transversely between the two tenons 16 and between the two corresponding slots 16′. The inclination angle of the lateral faces of the trapezoidal section may be 30°, as indicated in
The second face 14 of the two lateral faces comprises three slots, namely a central slot 18′ and two lateral slots 20′, corresponding to the central tenon 18 and the lateral tenons 20, respectively.
With reference more specifically to
The height h of the central tenon 18 and of the lateral tenons 20 is advantageously the same, between 8% and 15% of the width L of the block 2. For a width L of 175 mm, the height h may be around 20 mm. The depth h′ of the central slot 18′ and of the lateral slots 20′ is advantageously greater than the height h of the central tenon 18 and of the lateral tenons 20, for example by a value of between 1 and 3 mm.
With reference to
The block that has just been described may have a length of 350 mm and a height of 200 mm. However, it will be understood that these dimensions are purely by way of example and that other dimensions are conceivable. This is also why the majority of the dimensions detailed above have been expressed as a percentage in order to be applied to other block dimensions.
The block may be produced by injecting the inert material into moulds, followed by hardening and demoulding. The block is advantageously made in one piece from the inert material. The latter may comprise a binder and one or more fillers. Among these fillers, there may be bio-based materials.
The geometry of the block according to the invention that has just been described is the result of detailed studies with the objective of reconciling static strength and ease of assembly, in particular without the use of mortar.
The construction block 102 illustrated in
The material of the levelling layers is advantageously a mortar comprising substantially granules and a cement-based binder. On account notably of the imperfections of a wall constructed from the blocks in question, the granules advantageously have an average diameter limited to half the thickness of the levelling layer and may disintegrate finely in order to increase the effective contact area in the event of a localized compressive force. More specifically, the granules, once separated from the matrix, fill the adjoining gaps in the contact interface between the rough surfaces. The compression of the levelling layer makes it possible to avoid a discontinuity of the surfaces of the superposed blocks, and thus ensures uniform load transfer between the blocks.
During any production of building blocks, the production tolerances of the machines and the effects of different contraction mean that, after drying, the blocks are almost never the same height. Moreover, the surfaces of the building blocks are in no case smooth but always have irregularities that create roughness. The dry stacking of building blocks thus gives rise to two geometric imperfections, namely:
Each of these imperfections has a negative effect on the strength of the blocks and of the wall in a well-defined way. Specifically, the variation in height of the blocks results in an almost unpredictable path for the passing down of load in the wall, while the roughness of the faces of the block amplifies the concentration of the loads at the dry joints. The cumulative effect of these two imperfections considerably decreases the useful section of the dry-laid masonry walls, this ultimately causing a high concentration of the loads and resulting in premature cracking of the walls.
The orders of magnitude of the thickness of the levelling layer are advantageously between 5 mm and 40 mm, more advantageously between 10 mm and 30 mm, depending on the production tolerance (in terms of height) of the building blocks.
The performance of the levelling layer is substantially based on the mechanical properties of the material, which are: the compressive strength, Young's modulus, density, Poisson's ratio, granulometry and stress-deformation relationship.
Digital and experimental investigations show that the materials Mat 1, Mat 2 and Mat 3 have a high regulating potential with regard to the inevitable geometric imperfections of the dry-laid building blocks. Essentially with regard to the roughness of the laying faces of the blocks, these materials make it possible to ensure 90% uniform contact for a low load level 13% of the ultimate load of the building block).
Table 1 indicates a number of essential mechanical properties of the materials Mat 1, 2 and 3, showing the properties such as Young's modulus, the ultimate compressive strength of each material and the coefficient of friction of the abovementioned materials.
The levelling layer has a high regulating potential with regard to the imperfection of the contact surfaces. The relevance of the influence thereof is shown further by the reduction in Young's modulus of the material used.
The variation in height of the building blocks with respect to one another reduces the useful section in the different rows of dry-laid walls. In order to analyse their effect and see the influence of the contact layer, an analytical and statistical approach has been developed. Statistical studies which have been carried out on several systems for passing down load in walls have resulted in the curves shown in
The levelling layer(s) may be produced by successive injection of different materials into a manufacturing mould, thereby ensuring very good cohesion and limited manufacturing costs.
| Number | Date | Country | Kind |
|---|---|---|---|
| LU93263 | Oct 2016 | LU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/076241 | 10/13/2017 | WO | 00 |
