Raw-earth building block, manufacturing method, and corresponding construction assembly

Abstract

The invention relates to a building block (1) having a generally rectangular parallelepiped shape, characterized in that same has a hollowness rate (2) between 40% and 60% and has a volume greater than 10 dm3, said raw earth comprising at least one granular material representing between 60 and 80% of the total composition, and at least one binder material representing between 20% and 40% of the total composition.

Description

[0001] DESCRIPTION

[0002] TITLE: Raw earth building block, manufacturing method and corresponding construction set

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The field of invention is that of construction.

[0005] The invention relates more particularly to a method of manufacturing a raw earth building block. The present technique also relates to the raw earth block obtained via this method, as well as to a construction assembly comprising such blocks.

[0006] TECHNOLOGICAL BACKGROUND

[0007] Current constructions mainly use hollow concrete blocks, commonly called "breeze blocks," with an optimized size-weight ratio for easier handling. In addition, these constructions require the use of mortar, such as cement joints, to hold the concrete blocks together. However, current environmental considerations tend to call into question the use of concrete and cement, which have a relatively high carbon footprint.

[0008] Thus, in order to reduce the carbon footprint of constructions, solid earth bricks can be used. However, these bricks generally have much smaller dimensions (approximately 8 x 10 x 20 cm) causing a significant increase in the assembly time of the entire construction.

[0009] It is therefore necessary to propose a simple and quick solution to implement, with a low environmental impact, while maintaining significant mechanical resistance and good load-bearing capacity.

[0010] SUMMARY OF THE INVENTION

[0011] The present invention relates to building blocks and a method for obtaining them, as well as to building assemblies comprising such building blocks and the use of a building assembly (when it comprises a chain) for the construction of a building in a seismic zone.

[0012] More particularly, in order to resolve the problems and drawbacks of the prior art, the applicants have developed a raw earth building block of generally rectangular parallelepiped shape, characterized in that it has a hollowing rate of between 40% and 60% and has a volume greater than 10 dm 3, said raw earth comprising at least one granular material representing between 60% and 80% of the total composition and at least one binding material representing between 20% and 40% of the total composition.

[0013] By block volume we mean the external volume of the block, in other words, the volume of the block's envelope including the recesses and solid areas.

[0014] Thus, this building block allows a gain in materials, and in lightness allowing it to be maneuverable and easy to implement, while having good mechanical properties. In addition, the use of raw earth makes it possible to reduce the environmental impact of the final construction, in comparison with the concrete blocks of the prior art. Indeed, such a block does not require cooking which makes it possible to reduce the energy consumption linked to its production. In addition, the raw earth used in the manufacture of this block can be reconstituted from co-products of quarries or excavated earth (more generally, materials from extractive industries and / or construction), thus recovering these materials ordinarily considered as waste. The building block according to the invention is therefore light, resistant, economical and ecological.

[0015] Furthermore, the building block allows for an improvement in construction speed due to its large dimensions, compared to earth bricks of the prior art. In addition, the blocks according to the invention allow for a relatively high laying rate due to their lightness and dimensions, as well as due to the fact that they do not require the use of mortar for their assembly.

[0016] In addition, the proportions of granular material and binder material respectively provide a strong skeleton and keep the skeleton elements linked together. Thus, these proportions make it possible to obtain optimal mechanical properties, meeting, among other things, the NF EN 771-3 and XP 13-901 standards. Furthermore, the formulation of the raw earth used for the manufacture of the building block can also make it possible to obtain different colorimetric shades depending on the origin of the binder material, without adding coloring.

[0017] Furthermore, the geometry of the building block can also fall within the requirements defined in Group 2 “Elements made up of vertical cells” of Table 3.1 of the French standard EN 1996-1-1 (EC6), in particular in terms of dimensions and mechanical resistance in compression, it being understood that the blocks according to the invention are intended to be assembled without assembly mortar.

[0018] In addition, this building block remains lightweight with a final weight preferably less than 20 kg. Thus, the building block is easily handled.

[0019] Advantageously, said hollowing rate may be between 40% and 50%.

[0020] Advantageously, said at least one granular material may belong to the granular class 04 / or 0 / 8.

[0021] Such a granular material may be, for example, a 0 / 8 or 0 / 4 type sand, or equivalent. This type of sand (or equivalent) is a co-product of quarrying or excavated earth, so that the building blocks according to the invention allow the recovery of waste from extractive industries or construction (Building and Public Works). In addition, such grain dimensions make it possible to optimize the mechanical strength / cohesion ratio of the block. Indeed, the grain size of the granular material must be high enough to obtain the desired mechanical properties (NF EN 771-3 and XP 13-901), while respecting a maximum threshold in order to be adapted to the thickness of the walls of the block, and allow the binding material to provide cohesion to the whole.

[0022] Advantageously, the binder material may comprise fine particles representing between 20% and 40% of the total composition of said raw earth, and a hydraulic binder such as a low-carbon hydraulic binder, hydraulic lime or any alternative binder that can be bio-sourced in an amount equal to or less than 5% of the total composition of said raw earth.

[0023] As regards the fine particles, these may have a particle size such that the 63 pm sieve size corresponds to at least 75% of the total mass of the fine particles of the binder material. For example, as fine particles which can be used in the context of the present invention, mention may in particular be made of washing fines, and in particular clayey fines.

[0024] For the purposes of the present invention, washing fines means the fine fraction of aggregates processed at the exit of the quarry. This fraction may, for example, come from the final stages of washing on a screen and / or hydraulic separation during the processing of materials from quarries.

[0025] Thus, the building blocks according to the invention allow the recovery of quarry waste such as fine particles or, more generally, waste from the extractive industry and / or construction. In addition, these types of materials allow the granular skeleton of the building block to be maintained.

[0026] As indicated previously, the binding material can also advantageously comprise, in addition to the fine particles, a hydraulic (or alternative) binder to improve the maintenance of the skeleton when the fine particles are not sufficient.

[0027] According to a particular characteristic, the building block according to the invention may have vertical through recesses, representing between 40% and 60% of the volume of said building block.

[0028] Such vertical through-cavities allow any lower blocks to be filled with a possible filling material, in order to obtain a reinforced and resistant construction assembly. More specifically, a construction block whose vertical recesses are filled can be assimilated, for example, to a solid block of Group 1 of Table 3.1 of the French standard EN 1996-1-1.

[0029] According to a particular characteristic, the building block according to the invention can have the following dimensions: a length of 50 cm, a width of 25 cm, a height of 12.5 cm.

[0030] Thus, the dimensions of the building blocks are similar to the dimensions of a standard half-block of dimensions 50 x 25 x 25 cm, commonly called a "concrete block". The implementation of the blocks according to the invention is therefore facilitated.

[0031] Furthermore, the present invention also relates to a construction assembly, comprising at least two construction blocks according to the invention, which are assembled without binder at the joints so as to be in direct contact with each other.

[0032] Thus, the construction assembly according to the invention is simple, quick and economical to implement. Indeed, it does not require the use of mortar or any other binder between the building blocks. In addition, the lightness of the blocks allows for simple and quick transport and implementation.

[0033] Such a building complex can be presented, for example, in the form of a masonry wall made up of a stack of raw earth building blocks.

[0034] Furthermore, the dimensions of the building blocks and the mortar-free installation make it possible to maintain a rate equivalent to the installation of a hollow concrete block wall and a rate higher than for compressed earth brick walls (raw or stabilized).

[0035] According to a preferred variant of the invention, the blocks can be stacked in a staggered pattern and have vertical recesses running through them, the recesses of said blocks being aligned, thus forming continuous vertical recesses running through the height of said construction assembly, said construction assembly comprising a filling material poured into said continuous vertical recesses, said filling material being composed of concrete and / or raw earth.

[0036] For the purposes of the present invention, continuous vertical recess means an empty column within the construction assembly, formed by the alignment of at least two through recesses of two stacked blocks.

[0037] Thus, the construction assembly according to the invention can be used as a load-bearing wall or not, a shear wall or not.

[0038] More specifically, such a construction set may be intended for the construction, in rehabilitation or new construction, of load-bearing walls, or non-load-bearing walls, or facade walls or interior walls in individual houses, collective residential buildings, establishments receiving the public of categories 1 to 5, establishments covered by the labor code, health and educational establishments, and more generally any type of building for commercial, industrial or agricultural use.

[0039] The construction assembly according to the invention allows the construction of single-story buildings up to four-story buildings. Furthermore, as mentioned previously, with filling of all vertical recesses either with raw earth or with reinforced concrete filling forming a chain, the construction assembly can be assimilated for example to a solid block masonry of Group 1 of Table 3.1 of the French standard EN 1996-1-1. Indeed, the filling material makes it possible to secure the blocks of the construction assembly and to improve their mechanical properties. In particular, the function of the filling material is to absorb shear forces in the wall.

[0040] Furthermore, once filled, the building block according to the invention makes it possible to achieve a compressive strength of 8.1 MPa, which complies with the requirements of Group 1 of Table 3.1 of the French standard EN 1996-1-1 in terms of mechanical properties, for which this strength must be greater than 8 Mpa.

[0041] In addition, the construction assembly makes it possible to achieve a characteristic compressive strength (exerted stress divided by 1.2) on a wall measured according to standard NF EN 1052-1 of at least 2.8 Mpa.

[0042] With regard to fire safety, the construction assembly according to the invention meets the requirements at most equal to REI 120 according to the decree of March 22, 2004, amended in March 2011, relating to the fire resistance of products, construction elements or works.

[0043] In an advantageous embodiment, the filling material may be composed of raw earth comprising: at least one granular material representing between 60% and 90% of the total composition; at least one binder material representing between 10% and 30% of the total composition; earth from the construction site representing between 0% and 20% of the total composition.

[0044] According to a particular embodiment, the filling material may be composed of raw earth comprising: between 50% and 70% of quarry waste type 0 / 20; between 10% and 30% of sand type 0 / 4 to 0 / 8; between 10% and 30% of fine particles, for example such fine particles may comprise fillers, crushed fillers, washing fines, etc.; between 0% and 5% of hydraulic binder or low-carbon hydraulic binder or hydraulic lime or bio-sourced alternative binder; between 0% and 20% of earth from the construction site.

[0045] Thus, this filling material has the same rheological behavior as concrete, and has a consistency that can be between S2 and S5 according to standard NF EN 206, preferably between S4 and S5.

[0046] In addition, this filling material has a compressive strength greater than or equal to 4 MPa and has the function of absorbing shear forces in the wall.

[0047] According to an advantageous embodiment of the invention, the construction assembly may comprise, in addition to the construction blocks according to the invention, accessory blocks of the lintel and / or planelle type.

[0048] For example, the use of accessory blocks at the level of the door frames, or at the level of the floors, makes it possible to obtain a construction assembly entirely in raw earth, making the exterior appearance of the construction assembly overall smooth and homogeneous.

[0049] Advantageously, the construction assembly according to the invention may also comprise a chaining within at least said continuous vertical recesses. Indeed, during the assembly of the building blocks, the alignment of the vertical recesses allows for the installation of so-called chained or confined masonry. Thus, a concrete-type filling material, poured into the continuous vertical recesses, may be supplemented by metal reinforcements in order to reinforce the structure. Consequently, the construction assembly may have characteristics that comply with the minimum construction provisions for vertical / horizontal chaining defined for example in DTU 20.1 P4, and comply with the Eurocodes if the chains are made of reinforced concrete.

[0050] Thus, the invention also relates to a use of a construction assembly comprising a chaining, for the construction of a building in a seismic zone. Indeed, by integrating a reinforced concrete chaining within certain continuous vertical recesses, this makes it possible to reinforce the structure in the strategic zones of the building, and thus to resist seismic stresses, so that the construction assembly can then be compliant for buildings requiring earthquake-resistant provisions. More particularly, such a construction assembly is suitable for construction in seismic zones 1 to 4 according to NF EN 1998-1-1.

[0051] The invention also relates to a method for manufacturing a raw earth building block of generally rectangular parallelepiped shape as defined above, said method comprising the following steps: selection of at least two materials among which at least one granular material representing between 60% and 80% of the total composition, and a binder material representing between 20% and 40% of the total composition; reconstitution of a raw earth from said at least two selected materials; filling a mold corresponding to the generally rectangular parallelepiped shape, with said reconstituted raw earth; compacting said reconstituted raw earth within the mold, said compacting step implementing a vibration step, the vibration frequency during the compacting step being greater than 9000 rpm; demolding said compacted raw earth, delivering said raw earth building block.

[0052] Thus, the geometry and mechanical characteristics of the building block are the result of the combination of both an optimal and robust recomposition of natural materials and a strong densification applied by an industrial tool combining vibration and compaction.

[0053] The settings of the industrial tool are adapted to the nature of the material in order to obtain a high densification and ultimately good strength, while maintaining a production rate equivalent to the manufacture of hollow concrete blocks with reduced costs and carbon footprint due to the materials used. Indeed, the drying time is reduced thanks to the manufacturing parameters specific to the process according to the invention. In addition, the industrial tool can be automated to facilitate and further accelerate production. Furthermore, the process according to the invention makes it possible to obtain a very low variation in the dimensions of the building blocks, with for example a dimensional tolerance on the height of plus or minus 1 mm. The very low dimensional variation of the building blocks obtained using this process allows a very close-fitting assembly and facilitates the possible laying of the building blocks without mortar.

[0054] The mold used in the process according to the invention therefore has an internal shape that is generally a rectangular parallelepiped, and allows the creation of recesses representing between 40% and 60% of the volume of the rectangular parallelepiped.

[0055] In addition, the use of raw earth helps reduce the environmental impact of construction. Indeed, such a process for manufacturing a building block does not require a firing step, which reduces energy consumption. In addition, the raw earth used in the manufacture of this block can be reconstituted from quarry co-products or excavated earth (more generally, materials from extractive industries and / or construction), thus recovering these materials ordinarily considered as waste. The building block according to the invention is therefore light, strong, economical and ecological.

[0056] Indeed, the proportions of granular material and binder material respectively provide a strong skeleton and keep the skeleton elements linked together. Thus, these proportions make it possible to obtain optimal mechanical properties, meeting, among other things, the NF EN 771-3 and XP 13-901 standards.

[0057] In addition, a vibration frequency greater than 9000 rpm ensures good distribution of the compacted raw earth within the mold, while promoting the subsequent drying stage of the block. The vibration is carried out on the assembly comprising the mold and the raw earth inserted into it and can be implemented during or after compaction. Thus, the compaction stage of the manufacturing process is optimized and makes it possible to obtain raw earth that perfectly matches the shape of the mold, and is very compact with a density greater than 2000 kg / m 3, which improves the mechanical properties of the final building block.

[0058] According to a preferred variant of the invention, a vibration step can also be implemented during the filling step. The vibration is carried out on the assembly comprising the mold and the raw earth inserted therein and can be implemented during or after filling. Thus, the filling step of the manufacturing process is optimized and makes it possible to obtain a more compact and dense raw earth, perfectly matching the shape of the mold, which improves the mechanical properties of the final building block, and which makes it possible to obtain building blocks of constant dimensions.

[0059] Advantageously, the vibration frequency during the filling stage is greater than 3000 rpm. Such vibration ensures good distribution of the raw earth within the mold.

[0060] According to a particular characteristic, the compaction step uses compression means applying a pressure greater than 120 bars.

[0061] The process thus produces a dense and compact block with reduced drying time, allowing automated palletization in a time similar to that of hollow concrete blocks, and presenting good mechanical properties meeting the NF EN 771-3 and XP 13-901 standards.

[0062] According to a particular characteristic, the duration of the filling step is between 2 and 5 seconds.

[0063] Thus, the manufacturing process is quick to implement, and requires little time for the filling stage.

[0064] According to a particular characteristic, the vibration duration during the compaction stage is between 5 and 15 seconds maximum.

[0065] Thus, the manufacturing process is quick to implement, and requires little time for the compaction / vibration step.

[0066] Depending on the conditions, a block drying step may be implemented following the demolding step. The drying time depends on the composition of the raw earth as well as the remaining water content after compaction. This drying is preferably carried out in the open air.

[0067] Furthermore, raw earth used for building blocks or as a filling material can be reconstituted through an industrial process which may include several stages such as: selection and sorting of materials, for example by screening; mixing and homogenization of the selected materials.

[0068] BRIEF DESCRIPTION OF THE FIGURES

[0069] Other aims, characteristics and advantages of the technique will appear on reading the following description given for illustrative and non-limiting purposes only, and which refers to the appended figures, and to the examples. The figures include:

[0070] [Fig. 1] represents two three-dimensional building blocks according to an exemplary embodiment of the invention;

[0071] [Fig. 2] is a diagram of a block according to three different views, with dimensions, according to an example of realization;

[0072] [Fig. 3] represents a cross-section of the block shown in Figure 2;

[0073] [Fig. 4] represents a longitudinal section of the block shown in Figure 2;

[0074] [Fig. 5] represents a construction set comprising blocks according to an exemplary embodiment of the invention.

[0075] DETAILED DESCRIPTION

[0076] Figure 1 represents an exemplary embodiment of the invention, in which the recesses 2 of the blocks 1 are vertical and through. Indeed, Figure 1 represents two different views of blocks in three dimensions, placed on one of their sides.

[0077] The raw earth block can be manufactured, among other things, from different materials from various extractive industries, for example: quarry (co)products (e.g.: tertiary sand, discovery materials); and / or quarry waste (e.g.: tailings, washing fines); and / or construction waste, excavation earth, construction site earth.

[0078] Thus, the manufacture of such blocks makes it possible to recover “waste” materials or materials that are not highly recovered in prior art methods.

[0079] According to an exemplary embodiment represented by figures 1 to 4, the building block has dimensions of 50 x 25 x 12.5 cm, and is comparable to a half-concrete block of the prior art. The thickness of the raw earth facing is at least 4 cm, more precisely 4.25 cm in figure 2, and the block comprises two through-square recesses of at least 16 cm on each side, more precisely 16.5 cm in figures 2 and 3.

[0080] Furthermore, the recesses 2 shown in Figures 1 to 4 have fillets 3 on each of their edges. These fillets 3 can, for example, facilitate the subsequent filling of the recesses with a filling material by avoiding creating areas that are difficult to access or likely to retain air bubbles. In addition, such fillets can also limit the concentration of stresses in the corners and play a role in mechanical reinforcement.

[0081] In addition, the building blocks shown in Figures 1 to 4 also have optional notches 4 in the lower part of each of their ends, these notches making it possible, for example, to facilitate the gripping of the raw earth building block. These notches can also make it possible to control the diffusion of any filling material when it is added to the recesses of the raw earth building block. Figures 1 to 5 show blocks having a notch at each of its ends, however, a block having only one notch, arranged in the lower part, is also possible.

[0082] Finally, the building blocks shown in Figures 1 to 4 also have a groove 5 on their lower face, between the two vertical through recesses 2. These grooves can thus make it easier to cut the blocks.

[0083] In connection with Figure 5, a building set is described, consisting of a set of building blocks forming a vertical wall.

[0084] More specifically, Figure 5 represents a dry stacking of the building blocks, with vertical joints offset from one layer to the other, more precisely in a staggered pattern. The building blocks shown have vertical recesses superimposed / aligned to form continuous vertical recesses, in the height of the wall. These continuous vertical recesses can then be filled in s / tu with a specific raw earth mixture in the current zone and / or reinforced concrete in accordance with the minimum construction provisions for vertical / horizontal chaining defined in the French standard DTU 20.1 P4. Figure 5 also shows that the raw earth building blocks can have notches in the lower part of each of their ends, these notches making it possible to create a specific structure with the filling material. Indeed, such notches make it possible to connect two by two each of the continuous vertical recesses formed in the height of the wall.This allows for a strong construction set by improving the bonding of the building blocks and creating a specific structure reinforced with the filling material.

[0085] EXAMPLES

[0086] The following examples illustrate the invention, without however limiting its scope.

[0087] PRODUCTS AND RAW MATERIALS

[0088] The raw earth used for the manufacture of building blocks according to the embodiments described below comprises: a granular material representing between 60% and 80% of the total composition, consisting of tertiary sand belonging to the granular class 0 / 4 or 0 / 8; a binder material representing between 20% and 40% of the total composition, and comprising: o fine clay particles resulting from the washing of granular materials representing between 20% and 40% of the total composition of the raw earth, and o a hydraulic binder (cement) according to standard NF EN 197-1 representing between 0% and 5% of the total composition of said raw earth.

[0089] The filling material used to fill the recesses of the building blocks according to the embodiments described below comprises: granular materials: o between 50% and 70% of clayey quarry waste of type 0 / 20; o between 10% and 30% of sand of type 0 / 4; binding materials: o between 10% and 30% of siliceous fines of type 0 / 2; o between 0% and 5% of cement, lime, and admixture; between 0% and 20% of earth from the construction site.

[0090] CHARACTERIZATION TESTS

[0091] Characterization of the building blocks according to the invention, empty and filled: o measurement of the compressive strength (with the voids unfilled, on net surface): this measurement was carried out in accordance with the method presented in standard NF EN 772-1; o measurement of the compressive strength (with the voids filled, on total surface): this measurement was also carried out in accordance with the method presented in standard NF EN 772-1; o measurement of the thermal conductivity: this measurement was carried out in accordance with the method presented in standard NF EN 12664; o measurement of the coefficient of resistance to diffusion of water vapor: this measurement was carried out in accordance with the method presented in standard NF EN ISO 12577.

[0092] Characterization of the filling material: o in the fresh state, assessment of the consistency in accordance with standard NF EN 206-1; o in the solid state, measurement of the compressive strength in accordance with standard NF EN 12390-3.

[0093] Characterization of low wall type construction assemblies comprising building blocks and a filling material according to the invention: o measurement of the compressive strength carried out in accordance with the method presented in standard NF EN 1052-1; this compressive strength is calculated by taking the minimum value between the minimum stress exerted before rupture and the average stress divided by 1.2; o measurement of the bending strength carried out in accordance with the method presented in standard NF EN 1052-2, which is measured either on the plane parallel to the horizontal joints or on the plane perpendicular to the vertical joints; o measurement of the fire resistance REI in minutes carried out in accordance with the method presented in standard NF EN 1365-1. The measured REI corresponds to the duration during which the construction assembly has a fire-resistant effect.; o measurement of the sound reduction index Rw (C ; C tr) in decibels, in accordance with the method presented in standard NF EN ISO 10140-2.

[0094] EXAMPLE 1: Production of unfilled building blocks according to the invention

[0095] From the raw earth for building blocks, building blocks according to the invention are produced as shown in Figures 1 to 4 using the method according to the invention and defined above. These are blocks with dimensions of 50 x 25 x 12.5 cm with a raw earth facing thickness of 4.25 cm, these blocks also comprising two square through recesses of 16.5 cm on each side (see Figures 2 and 3).

[0096] EXAMPLE 2: production of building blocks according to the invention filled

[0097] Building blocks of Example 1 were filled with the raw earth filler material as defined previously.

[0098] EXAMPLE 3: construction of low walls using building blocks according to the invention

[0099] Low walls were made from the building blocks as described in Example 1, stacked dry, in a staggered pattern, and whose through recesses form continuous vertical recesses in the height of the low wall. These continuous vertical recesses are then filled with a filling material as defined previously, in order to maintain and reinforce the construction assembly.

[0100] RESULTS OF CHARACTERIZATION TESTS

[0101] Tests were carried out on the building blocks of Examples 1 and 2, the filling material used in Example 2, and the low walls of Example 3. More specifically, the characterization tests described above were applied to these different elements, in order to measure their mechanical, thermal, acoustic and fire resistance properties. Firstly, Table 1 below shows the results of the characterization tests carried out on unfilled building blocks of Example 1 and those filled with Example 2. Thus, as previously specified, compressive strength measurements were carried out according to standard NF EN 772-1 on unfilled blocks, and on blocks filled with earth-based filling material, thermal conductivity measurements were carried out according to standard NF EN 12664, and water vapor diffusion resistance coefficient measurements were carried out according to standard NF EN ISO 12577.

[0102] Table 1 shows that the compressive strength values ​​of the empty blocks (of the order of 7 MPa) comply with the requirements of standards NF EN 771-3 and XP 13-901, namely Rc greater than 4 MPa for a B40 type block according to standard NF EN 771-3, and fall within the requirements defined in Group 2 “Elements made up of vertical cells” of Table 3.1 of the French standard EN 1996-1-1 (EC6).

[0103] In addition, the compressive strength values ​​of blocks filled with a filling material comprising raw earth also comply with the requirements of Group 1 of Table 3.1 of the French standard EN 1996-1-1 in terms of mechanical properties, namely Rc greater than 8 MPa.

[0104] [Table 1]

[0105] Table 2 below shows the results of the characterization tests carried out on the raw earth-based infill material. More specifically, measurements were carried out on the earth-based infill material as described above, in the fresh state, in order to assess its consistency in accordance with standard NF EN 206-1, and in the solid state, for compressive strength measurements in accordance with standard NF EN 12390-3.

[0106] Table 2 shows that the spread at the impact table is equal to or greater than 420 mm, which corresponds to the consistency of a fluid concrete of type S5 according to standard NF EN 206, in which it is indicated that category S5 corresponds to a spread greater than or equal to 220 mm. Thus, the fresh consistency of the filling material is well between S2 and S5 according to standard NF EN 206.

[0107] [Table 2]

[0108] Table 3 below concerns the tests carried out on the walls of example 3. In particular, table 3 shows that: the walls of example 3 have a compressive strength Rc on the wall (measured according to standard NF EN 1052-1) which is at least equal to 2.8 MPa: this value is obtained by calculation by taking the minimum value of the minimum stress exerted before rupture (equal to 3.1 MPa) and the average stress divided by 1.2 (equal to 3.3 / 1.2, i.e., 2.75 MPa). In addition, the average compressive strength on the walls is greater than 3.0 MPa; the walls of example 3 have a bending resistance on walls measured on the plane parallel to the horizontal joints of 0.84 MPa, while the average bending resistance on walls measured on the plane perpendicular to the vertical joints is 0.27 MPa.Thus, the construction set, the filling material, fulfills a function of absorbing shear forces in the wall. Indeed, the reference works dealing with the dimensioning of masonry works, as well as certain standards such as the NF DTU 20.1 (P10-202) standard recommend a resistance greater than 0.2 MPa in the plane perpendicular to the laying beds, and a resistance greater than 0.1 MPa in the plane parallel to the laying beds, in the case of masonry works with thin joint mortar.

[0109] [Table 3]

Claims

CLAIMS 1. Building block (1) made of raw earth with a generally rectangular parallelepiped shape, characterized in that it has a hollowing rate (2) of between 40% and 60% and has a volume greater than 10 dm 3 , said raw earth comprising at least one granular material representing between 60% and 80% of the total composition and at least one binding material representing between 20% and 40% of the total composition.

2. Building block (1) according to claim 1, characterized in that the hollowing rate of said block is between 40 and 50%.

3. Building block (1) according to one of claims 1 or 2, characterized in that said at least one granular material belongs to the granular class 0 / 4 or 0 / 8.

4. Building block (1) according to one of claims 1 to 3, characterized in that said at least one binding material comprises fine particles representing between 20% and 40% of the total composition of said raw earth, and a hydraulic or alternative binder representing between 0% and 5% of the total composition of said raw earth.

5. Construction set, characterized in that it comprises at least two construction blocks (1) according to one of claims 1 to 4, said at least two blocks (1) being assembled without binder at the joints.

6. Construction assembly according to claim 5, characterized in that said at least two blocks (1) are stacked in a staggered manner, said blocks (1) comprising vertical through recesses (2), the recesses (2) of said blocks (1) being aligned and forming continuous vertical recesses crossing in the height of said construction assembly, said construction assembly comprising a filling material poured into said continuous vertical recesses, said filling material being composed of concrete and / or raw earth.

7. Construction assembly according to claim 6, characterized in that said filling material is composed of raw earth comprising: at least one granular material representing between 60% and 90% of the total composition; at least one binding material representing between 10% and 30% of the total composition; earth from the construction site representing between 0% and 20% of the total composition.

8. Construction assembly according to claim 6, characterized in that said filling material is composed of raw earth comprising: between 50% and 70% of quarry waste type 0 / 20; between 10% and 30% of sand type 0 / 4 to 0 / 8; between 10% and 30% of fine particles; between 0% and 5% of hydraulic binder or low-carbon hydraulic binder or hydraulic lime or alternative binder; between 0% and 20% of earth from the construction site.

9. Construction assembly according to one of claims 6 to 8, characterized in that it further comprises at least one accessory construction block of the lintel and / or planel type.

10. Construction assembly according to one of claims 6 to 9, characterized in that it comprises a chain within at least one of said continuous vertical recesses.

11. Use of a construction assembly according to claim 10, for the construction of a building in a seismic zone.

12. Method for manufacturing a building block (1) made of raw earth of generally rectangular parallelepiped shape as defined according to one of claims 1 to 4, said method comprising the following steps: selection of at least two materials comprising at least one granular material representing between 60% and 80% of the total composition, and a binder material representing between 20% and 40% of the total composition; a step of reconstituting a raw earth from said at least two selected materials; filling a mold corresponding to the generally rectangular parallelepiped shape, with said reconstituted raw earth; compacting said reconstituted raw earth within the mold, said compacting step implementing a vibration step, the vibration frequency during the compacting step being greater than 9000 rpm; demolding said compacted raw earth, delivering said building block (1) in raw earth.

13. Manufacturing method according to claim 12, characterized in that the filling step implements a vibration step, the vibration frequency during the filling step being greater than 3000 rpm.

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