FR2928946A1 - Parallelepiped insulating block i.e. bond stone, for constructing e.g. house external wall, has cores arranged in staggered rows and aligned in row between two tangents, where tangents of two contiguous rows pass through cores of other row - Google Patents

Abstract

The block (1) has a sequence of rows (R1-R15) of parallelepiped or cylindrical hollow cores (2) traversing with each other in a through-and-through manner, where the sequence is constituted of columns (C0-C24) of parallelepiped hollow cores. The hollow cores are arranged in staggered rows and aligned in each row between two tangents (T1, T2), where the tangents of the two contiguous rows are joined and pass through the hollow cores of the other row. An independent claim is also included for a matrix for molding a block comprising a lateral vertical wall of rectangular shape and arranged on a horizontal plane support during filling process.

Description

Insulating block with a multitude of cells

The invention relates to an insulating block provided with a multitude of cells and intended for the construction of buildings. The field of the invention is that of the building. The block according to the invention can be used for the construction of external walls of buildings or houses, but also for the construction of interior walls for which certain properties are sought, certain characteristics to which the block according to the invention responds.

This type of block, called breeze blocks, has been used for a long time in the field of building construction. Manufacturers of such blocks have always sought to improve the quality of the insulating blocks they produce. This quality is assessed by studying certain properties of these blocks. The latter, which are the subject of improvement research are the following: - the blocks must be robust and have high resistance to high pressures because the weight they are intended to support for very long periods is very important - the blocks must have a good thermal coefficient as they are most often used for the construction of external walls and must therefore serve as insulation between the outside and the inside of a building, - the blocks must also have a good phonic coefficient in order to allow people working in the buildings with which they are built to carry out their activities without being disturbed by external noise, - the blocks must be as light as possible in order to improve their handling and thus make easier the building construction. Each type of product block is thoroughly tested for weight, strength, thermal coefficient and sound coefficient. All blocks must, for each of these characteristics, obtain results that meet pre-established standards. Moreover, these standards also fix different sizes allowed for these blocks. Among the materials used for the construction of such blocks, we find in particular brick, sand-lime brick, fly ash, pozzolan (volcanic rock), expanded clay, cellular concrete or cement plaster. Whatever the material used, the search for a good thermal coefficient is always one of the most delicate problems to solve. In order to improve the thermal coefficient of a block intended for the construction of buildings, it is known to produce a block structure presenting a maximum of breaks in the media. By rupture of medium, is meant the passage of a first medium composed of a first material to a second medium composed of a second material. In practice, the first medium consists of a material of the type of those mentioned above, and the second medium is made of air. Thus, a block intended for the construction of buildings is most often constituted by a succession of solid walls, that is to say of solid, and rows of hollow cells, that is to say of air holes within the block. A problem arises however: the blocks are made in molds, and they must be extracted from these molds without deformation of the solid walls. The solid walls must therefore be sufficiently solid, and therefore sufficiently thick to undergo this phase of extraction without deformation. As a result, the solid walls being thicker, the space available for the rows of cells is reduced, and their number is therefore relatively small. Block manufacturers are therefore looking for the ideal compromise between a maximum number of cell layers and the strength required to build the blocks. The various blocks of the invention are, in a non-limiting example, essentially composed of a pumice aggregate agglomerated with cement. The use of pumice to make such blocks has many advantages: in fact, pumice is distinguished first of all by its very low density. In addition, pumice stone has excellent fire resistance. In addition, the pumice stone has in its very structure natural air cavities that make it a very good sound insulation. Finally, another characteristic of pumice stone is that its water absorption coefficient is almost zero when it has undergone treatment. For comparison, the absorption coefficient of pumice is forty to one hundred times lower than the water absorption coefficient of the brick.

Table 1 below is a comparative table of the water absorption coefficient of various materials that can be used to produce blocks intended for the construction of buildings. The results are given in kilograms per square meter, for a material height of 50 centimeters. MATERIALS COEFFICIENT OF ABSORPTION OF WATER (kg / m2) Block of stone 0.209 to 0.25 pumice Coating cement 2.3 to 4.3 Concrete 2.1 to 7.0 cellular Silica brick 3.8 to 8.2 limestone Brick 9 to 30 Table 1

Pumice seems to be an ideal material for making blocks for building construction. However, its lightness 10 implies a certain fragility when it is crushed and that the granulate obtained is agglomerated with cement to form the blocks. Also, in order to solidify the blocks made of pumice stone, manufacturers are forced to thicken the solid walls of the blocks produced. Thus, for a given block width, solid walls which are solidified with added cement become wide. As a result, the number of rows of cells between the different solid walls decreases, which affects the thermal coefficient. In addition, the addition of cement considerably increases the production cost of a block and also considerably increases its weight, which makes it less manageable. The block which is the subject of the invention does not have this type of problem. Indeed, this block is made with a particular raw material that allows the presence of many rows of cells while ensuring good strength of the block, without posing particular problems when extracted from the mold in which it is manufactured. Moreover, the structure of this block has been determined following a multitude of tests to find an optimal thermal coefficient for this block. The structure also has a large number of cells that can impose thermal flow through the block a thermal path of unmatched length to date and thus to obtain an excellent compromise between a good thermal coefficient, a low weight and excellent mechanical strength. In addition, the manufacture of a block according to the invention will meet the requirements of the next international standard for energy consumption. The invention therefore relates to a block of generally parallelepiped shape, intended for the construction of buildings, comprising a succession of rows of hollow cells passing right through it, the succession constituting columns of hollow cells, the cells being arranged in staggered and aligned in each row between two tangents to this row, characterized in that - the tangents of two contiguous rows are merged or pass through the cells of the other row. The cells are staggered to avoid a so-called thermal bridge phenomenon. The invention and its various applications will be better understood by reading the following description and examining the figures that accompany it. These are presented only as an indication and in no way limitative of the invention. In particular, an example of a block is precisely described. But the invention should not be limited to this block. It concerns all blocks intended for the construction of buildings that have the general characteristics that are found in this block and which are claimed. In addition, the block and the cells described may have dimensions totally different from those mentioned below, while having the same structure. Finally, the described block can be divided into several blocks, for example into two identical blocks, which makes it lighter and therefore more manageable. The figures show: in FIG. 1, a top view of an exemplary embodiment of a block according to the invention; - In Figure 2, a top view of the same embodiment of the block according to the invention surmounted by a portion of a molding die; in FIG. 3, a side sectional view of a schematic representation of a filling of the molding die of the block according to the invention; FIG. 4 is a side sectional view of a schematic representation of a demoulding of the block molding die according to the invention. Figure 1 shows, in a view from above, a block 1 according to the invention, of generally parallelepiped shape. The structure of such a block 1 has been determined following a set of rigorous tests. The arrangement of the cells and their dimensions make it possible to obtain efficient thermal coefficients. A margin of fifteen percent over all the dimensions of the block 1 is possible without changing too much the thermal coefficients obtained with the exact dimensions given in the description which follows. Similarly, the block weighs about twenty kilograms to fifteen percent. The thermal coefficient of block 1 is about 0.4. This is likely to change if a particular treatment is applied to the pumice stone with which the block 1 is, in one example, manufactured. In one example, the block 1 has a length of 50 cm, a width of 32 cm and a height of 20 cm. In another example, not shown, the block has a width of 36 cm. In a preferred embodiment of the invention, block 1, intended for the construction of buildings, is composed in particular of pumice stone. In variants, the block is composed of pozzolan, or expanded clay, or fly ash. Block 1 comprises a succession of fifteen rows of hollow cells 2 parallel to the length of block 1. In this example, the section of the cells is circular and has a diameter of 20 mm. The cells 2 pass right through, i.e. from top to bottom, the block 1. In a variant, the cells have a section of any shape, for example polygonal. The succession of rows constitutes columns of cells 2, the set of cells 2 being arranged in staggered rows, in order to reinforce the resistance of the block 1 and to avoid a phenomenon of thermal bridge. The distance 3 separating adjacent edges of two contiguous cells 2 of the same row, for example R3, and the distance 4 separating adjacent edges of two adjacent cells of the same column, for example C7, are less than or equal to a diagonal length of section of a cell 2. In other words, the cells 2 are aligned in each row between two tangents to this row, and the tangents Ti and T2 of the two adjacent rows are merged. In a variant, the tangents of the same row pass through the cells 2 of the other row. According to the invention, the number of cells formed in a block is between 160 and 360. In the example described here, the block 1 has 168 cells. The rows of cells 2 are referenced from top to bottom R1 to R15. The rows R1, R3, R13 and R15 of cells 2 are identical: they all comprise eleven cells. The rows R2 and R14 of cells 2 are identical: they comprise ten cells and at each end a half-cell with a diameter of 60 mm. These half-cells 60mm in diameter are in fact antiseismic notches capable of cooperating with those of the neighboring block when two blocks are assembled side by side. In a variant, the rows R2 and R14 each comprise an anti-seismic allowance in place of one of the antiseismic notches in order to fill the antiseismic notch of the assembled neighboring block. The rows R4 and R12 of cells 2 are identical: they comprise ten cells. The rows R5, R7, R9 and R11 of cells 2 are identical: they all comprise eleven cells and, at each end, a half-cell of a diameter identical to that of the other cells of these rows R5, R7, R9 and R11. The rows R6, R8 and R10 of cells 2 are identical: they all comprise twelve cells. The cell columns 2 are referenced from left to right CO to C24. On the two smaller vertical faces of the block 1, the columns CO and C24 of cells 2 are identical: they each comprise four half-cells of the same diameter as the cells 2 and, at each end, a half-cell, or antiseismic notch, with a diameter of 60mm. Alternatively, the columns CO and C24 each have an anti-seismic allowance in place of one of the antiseismic notches to fill the antiseismic notch of the neighboring block assembled. The columns C1 and C23 of cells 2 are identical: they each comprise three cells 2. The columns C2, C4, C6, C8, C10, C12, C14, C16, C18, C20 and C22 of cells 2 are identical: they comprise all eight cells 2. The columns C3, C5, C7, C9, C11, C13, C15, C17, C19 and C21 of cells 2 are identical: they comprise all seven cells 2. FIG. 2 shows, according to FIG. same view from above, the same block 1 here surmounted by a portion of a matrix used for its molding. The matrix comprises a plurality of vertical rods 9 (visible in FIG. 3) of identical section to that of the cells 2, the rods being aligned and fixed together from above by means of holding bars 5. For the sake of clarity, only two of these holding bars have been shown. For cells 2 and cylindrical rods, the distance between two bars 5 is between the length of the radius and the length of the diameter of the cells 2. In one example, the bars 5 are parallelepipedal and have a section width of 12 millimeters; the distance between two bars 5 is then 16.28 millimeters. The pumice stone which, in one example, comprises the block 1 results from an agglomeration of a dry granulate of pumice stone and has a density of between 500 kg / m 3 and 700 kg / m 3. The pumice granulate underwent a fine removal operation prior to agglomeration. Figure 3 shows a side sectional view of a schematic representation of a filling of the molding die 6 of the block 1 according to the invention. The molding die 6 of a block 1 according to the invention has a vertical lateral wall 7 of rectangular shape, and rests, at the time of its filling, on a horizontal plane support 8. The rods 9 comprise at their upper end a slot in which the support bar 5 is inserted and then fixed by welding. The production of a block 1 according to the invention, by means of a matrix 6 according to the invention, comprises the stage in which, for example with pumice granulate agglomerated with cement, is filled from above. , an assembly formed by the matrix 6 and the plane support 8. The gap between the bars 5 as well as the cylindrical shape of the rods 9 allows easy filling of the matrix 6 because the raw material, in one example the grains of pumice stone , slide along the said rods 9. The rods 9 have at their upper end a slot in which the holding bar is inserted and then fixed by welding. Figure 4 shows a side sectional view of a schematic representation of a demolding of the molding die 6 of the block 1 according to the invention. To unmold the block, the die 6 is lifted vertically and, simultaneously with the uprising of the die, 13 is pressed against an upper surface of the block with a multitude of vertical pestles 14 to hold it on the flat support 8, and then the pestles 14 to release the molded block 1. In a variant, the cells 2 are obtained by piercing the block 1 after demolding. In this case, the matrix does not have a vertical rod.

The structure of block 1 is characterized by its compressive strength: it is 27 to 32 MPa (Mega Pascal). This resistance is partly due to the multitude of cells that intervene in its structure. In one example, the block 1 consists of an agglomerate of pumice stone whose weight per cubic meter at the extraction is between 800 kg and 900 kg, this value depending substantially on their particle size: for a particle size of 0/8, the average weight per cubic meter is 860 kg, and for a 5/8 particle size, the average weight per cubic meter is 840 kg. Humidity is 19 to 25 percent of the weight at extraction, dry weight is 780 kg and 700 kg respectively. By carrying out a removal operation of a set of dust particles, called fine before agglomeration of the pumice granulate, we arrive at a granulate of pumice stone whose average mass per cubic meter is reduced to 680 kg for a granulometry 0/8 and 660 kg for a particle size 5/8. Finally, the pumice stone that forms the block 1 results from an agglomeration of a dry pumice granulate having a density of between 500 kg / m3 and 700 kg / m3. One of the additional advantages in the construction of this block 1 is that it is enough to add little (from 110 to 120 kg per cubic meter) of cement to agglomerate the aggregates. The block thus formed is light and manageable.

Pumice can be quarried in Greece (Yali), Italy (Lipari Islands), France, Morocco or Peru (Arequipa). Table 2 below gives a chemical analysis of the pumice stone used for the production of the block I. This composition can obviously very slightly vary according to their origin. SiO2 silica 70.55 Alumina oxide AI203 12.24% Ferric oxide Fe2O3 0.89% CaO lime 2.36% MgO magnesia 0.10% S03 sulfur oxide 0.03% Potash oxide 1 (20 4.21 % Sodium oxide Na2O 3.49% Loss on ignition 5.51 Not determined 0.62% Table 2

Claims (10)

1 block (1) of generally parallelepipedal shape, intended for the construction of buildings, comprising a succession of rows of hollow cells (2) passing therethrough, the succession constituting columns of hollow cells, the cells being arranged in staggered rows and aligned in each row between two tangents in this row, characterized in that - the tangents (T1; T2) of two adjacent rows are merged or pass through the cells of the other row. 2- block according to claim 1 characterized in that the cells are parallelepipedic. 3- block according to claim 1 characterized in that the cells are cylindrical. 15 4- block according to one of claims 1 to 3 characterized in that the number of cells formed in a block is between 160 and 360. 5. Block according to one of claims 1 to 4 characterized in that it is composed of pumice resulting from an agglomeration of a dry granulate of pumice stone and having a density of between 500 kg / m3 and 700 kg / m3. 6. Block according to claim 5 characterized in that the pumice granulate has undergone a fine removal operation before agglomeration. 7. Block according to one of claims 1 to 6 characterized in that its mass is about 20 kilograms. 8- block according to one of claims 1 to 7 characterized in that it has on its two vertical faces the longest notch and / or an extra thick anti-seismic capable of cooperating with those of the neighboring block when two blocks are assembled side to side. 30 9- die (6) for molding a block according to one of claims 1 to 8, comprising a vertical side wall (7) of rectangular shape, and resting, at the time of its filling, on a horizontal plane support (8 ), characterized in that - it comprises a multitude of vertical rods (9) of section 35 identical to that of the cells, the rods being aligned and fixed to one another by the top, by means of parallel bars (5) for holding. 10- Matrix according to claim 9, characterized in that, for cells and cylindrical rods, the distance between two bars is between the length of the radius and the length of the diameter of the cells.