Construction element comprising one or more internal cells filled with a mixture comprising at least one bio-sourced material

Abstract

The invention relates to a construction element (1) comprising a concrete structure of generally rectangular parallelepiped shape having two substantially planar longitudinal faces (11, 12), two transverse faces (13, 14) connecting the longitudinal faces (11, 12), a substantially planar upper face and a substantially planar lower face, characterized in that said structure comprises at least one internal cell (15) opening on only one of the upper and lower faces of the construction element or on both the upper (15) and lower faces, said at least one internal cell (15) being filled with a mixture comprising at least one biosourced material. [Fig 1]

Description

Title of the invention: Construction element comprising one or more internal cells filled with a mixture comprising at least one bio-sourced material FIELD OF THE INVENTION

[0001] The invention relates to the field of building construction, in particular eco-responsible and sustainable construction.

[0002] The invention relates more particularly to a construction element, for the construction of residential buildings (individual houses for example), industrial or agricultural buildings in particular. PRIOR ART SOLUTIONS

[0003] The building and construction sector is one of the sectors most concerned by the challenges of sustainable development. At the heart of sustainable development issues, construction uses ecological materials to create environmentally friendly buildings, with a reduced carbon impact.

[0004] Concrete blocks made from ecological concrete, known as low carbon, have thus been proposed as an alternative to concrete blocks or manufactured concrete blocks (abbreviated as BBM), commonly referred to as "concrete blocks". For example, concrete blocks made from cellular concrete, plant-based concrete (hemp in particular), pumice stone or even wood are known. These building blocks are, however, relatively expensive. Their uses are therefore currently relatively marginal compared to all the constructions carried out.

[0005] In order to improve the carbon footprint of building blocks while providing good thermal resistance, the Applicant proposed in patent FR 3 023 859 B1 a concrete block comprising internal cells in which an insulating material in the form of foam is integrated.

[0006] However, it is always necessary to improve the quality of building blocks to meet the criteria of energy and environmental exemplarity. Statement of the invention

[0007] The object of the invention is to make concrete-based construction more environmentally friendly. To this end, a construction element is proposed comprising a concrete structure of generally rectangular parallelepiped shape having two substantially planar longitudinal faces, two transverse faces connecting the longitudinal faces, and a substantially planar upper face and lower face. According to the invention, said structure comprises at least one internal cell opening on only one of the upper and lower faces of the construction element or on both faces on upper and lower, said at least one inner cell being filled with a mixture comprising at least one bio-sourced material.

[0008] The construction element developed by the inventors therefore takes the form of a concrete building block having one or more cells in which a mixture containing one or more bio-sourced elements is incorporated, this mixture having insulating properties or not.

[0009] The bio-sourced element(s) come from biomass of plant or animal origin. These may be plant aggregates, agricultural or forestry operating residues.

[0010] It may more particularly be wheat, rapeseed, hemp, sawdust, wood shavings, cork, sugar cane, banana trunk, corn stubble, barley, rye, sisal or jute.

[0011] These may in particular be pectocellulosic products (pectose, flax, chanter, ramie, bamboo) or lignocellulosic products (lignite, jute, cereal straws such as wheat straw).

[0012] It can also be material from animals, such as sheep's wool.

[0013] It can also be materials from recycling such as recycled cotton or cellulose wadding.

[0014] Wood chips or sawdust can come from forest felling waste (trees, branches, bark).

[0015] The use of such bio-sourced materials has many advantages.

[0016] On the one hand, they are unanimously recognized for their insulating qualities. A bio-sourced material will naturally play the role of temperature and humidity regulator. The insulation offered is better, as is the ventilation. The comfort of the home is therefore superior, with energy savings to be made in summer as well as in winter.

[0017] On the other hand, these are materials that have a positive impact on the environment, because they store the carbon present in the air. They actively participate in the reduction of greenhouse gases and undergo less chemical treatments.

[0018] Furthermore, this opens up a new avenue for reusing these materials. It is notably an economic outlet for certain by-products of forestry exploitation such as sawmill waste.

[0019] A concrete building block incorporating such bio-sourced materials into its internal cell(s) has a good thermal and sound coefficient, a reasonable manufacturing cost and a reduced weight making it easy to handle on site in particular. It fits perfectly into the framework of eco-responsible construction.

[0020] The use of bio-sourced materials does not impact the way of working on construction sites.

[0021] 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.

[0022] According to a particular aspect of the invention, the mixture is in the form of a paste comprising at least one biosourced material and a binder.

[0023] Advantageously, the binder of the paste comprises a mixture of sulfoaluminous cement, slag, clinker, fly ash, pozzolans and water.

[0024] According to a particular aspect of the invention, said at least one bio-sourced material is a residue from agricultural or forestry operations, or comes from recycling.

[0025] According to a particular aspect of the invention, said at least one bio-sourced material being wood in the form of sawdust or shavings.

[0026] Advantageously, the mass proportion of wood in the mixture is between 30 and 90%.

[0027] According to a particular aspect of the invention, said at least one bio-sourced material is included in dispersion in concrete or cement foam.

[0028] Advantageously, the cement foam comprises a cement slurry comprising: a first cement containing clinker or slag; a second sulfoaluminous cement; water, and a foam comprising water, air and a foaming agent. LIST OF FIGURES

[0029] Other characteristics and advantages of the invention will appear more clearly on reading the following description of two preferred embodiments, given as simple illustrative and non-limiting examples, and the appended drawings, among which:

[0030] - [Fig.l] is a top view of a construction element according to a method of rea embodiment of the invention, taking the form of a concrete block with several internal cells each filled with a mixture comprising at least one bio-sourced material;

[0031] - [Fig.2] is a table detailing the mass proportions of elements constituting a wood-based mixture intended to be incorporated into one or more cells of a construction element according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] The invention relates to a construction element, in the form of a building block for example, intended for example for the modular construction of a building wall by stacking rows of blocks. This construction element is manufactured by molding consisting in particular of injecting concrete inside a mold to obtain at least one block in the shape of a parallelepiped.

[0033] In the embodiment of [Fig.l], the construction element 1 is a block of rectangular parallelepiped shape with six faces and has two parallel and substantially planar longitudinal faces 11, 12, two transverse faces 13, 14, as well as a face upper and a lower face (not visible). Several internal partitions define with the transverse walls 13, 14 and define, as well as with the longitudinal walls 11, 12, six internal cells or recesses 15 of rectangular shape.

[0034] These internal cells or recesses 15 open onto only one of the upper and lower faces of the construction element or onto both the upper and lower faces (in this case they are through and open).

[0035] L is the length of this construction element 1, E its thickness and H its height.

[0036] The construction element 1 comprises a framework based on heavy, common or light aggregate concrete (in which conventional aggregates such as sand and gravel have been replaced by naturally light and insulating materials, such as pumice stone, expanded slate or expanded clay, for example).

[0037] The six internal cells or recesses 15 are filled with at least one mixture comprising at least one bio-sourced material, which may be, for example, wood, such as recycled wood (wood waste) which may be in the form of sawdust or shavings.

[0038] This mixture may or may not be insulating.

[0039] It may be in the form of a paste comprising at least one bio-sourced material and a binder, the binder of the paste comprising a mixture of sulfo-aluminous cement, slag, clinker, fly ash, pozzolans and water.

[0040] The table in [Fig.2] details the mass proportions (minimum and maximum %) of the various elements constituting a wood-based mixture intended to be incorporated into the cells of a construction element according to the invention. This mixture is in the form of a paste comprising 30 to 90% by mass of wood, 5 to 30% by mass of sulfoaluminate, 5 to 30% by mass of slag, 0 to 10% by mass of clinker, 0 to 20% by mass of fly ash and 0 to 20% by mass of pozzolans. The slag, clinker, ash and pozzolans can be provided by CEM I, II, III or V type cements.

[0041] The binder of the paste can be supplemented with additive(s) facilitating setting such as sodium or calcium carbonate, alkalis, etc.

[0042] More generally, the binder may be mineral or not.

[0043] Alternatively, the bio-sourced material is included in dispersion in concrete or cement foam.

[0044] obtained from a cement grout and a foaming agent.

[0045] Bio-sourced materials have a positive impact on the environment because they store carbon present in the air. They actively participate in the reduction of greenhouse gases and undergo less chemical treatment.

[0046] The solution of the invention thus makes it possible, by sequestering CO2, to reduce the impact carbon CO2 significantly, that is to say to reduce this impact by half, or even to cancel it, or even to make it negative depending on the compositions and the mass of the mixture which can be introduced into the block.

[0047] Thus, a construction element comprising this type of bio-sourced material fits perfectly into the framework of eco-responsible construction. A bio-sourced material used in such a construction element naturally plays the role of temperature and humidity regulator.

[0048] The solution of the invention also offers an economic outlet for certain by-products of forestry exploitation, such as sawmill waste. Using bio-sourced materials in construction makes it possible to exploit renewable resources. In addition, this makes it possible to limit the use of materials manufactured from fossil fuels and mineral resources subject to high tension.

[0049] As true “carbon sinks”, bio-sourced materials, such as wood, contribute to reducing greenhouse gas emissions and have an interesting carbon footprint throughout their life cycle: during their cultivation, their processing, their supply (they are available locally), their implementation (carbon sink) in a construction element conforming to the invention and their end of life (they are biodegradable).

[0050] The recovered material can be crushed, ground or shredded depending on its nature, to obtain grains, fibers or pieces of predetermined dimensions.

[0051] Thus, the construction element according to the invention offers numerous advantages which have been validated by tests (acoustic absorption, thermal resistance, hygrothermal regulation).

[0052] For example, wood offers excellent thermal and acoustic performance. Cork obtained from cork oak or recycled corks is a biodegradable material that is additive-free and rot-proof. With a good reaction to fire, it offers good thermal and acoustic performance, like wood. Straw is a very economical bio-sourced material that requires no treatment. Hemp regulates humidity, with a good response to fire. With good thermal and acoustic performance, hemp is perfect for insulating attics, walls or roof slopes. Wood-based paper or cardboard are recyclable and economical materials. Cellulose wadding, made from recycled newspapers, has excellent insulation performance. It is known for its thermal inertia, ideal for seasonal changes, and its flame-retardant properties.

[0053] A bio-sourced material naturally acts as a temperature and humidity regulator. The insulation provided is better, as is the ventilation. The comfort of the home is therefore superior, with energy savings to be made in summer as well as in winter.

[0054] In the embodiment of [Fig.l], the transverse faces 13, 14 of the construction element 1 have an end surface shaped in such a way that a transverse face 13 of the construction element 1 fits from above into a transverse face 14 of another construction element 1.

[0055] Thus, the transverse faces 13, 14 of the construction element 1 are cut out and each have means of assembly or fitting respectively to another construction element 1.

[0056] In the illustrated embodiment, the assembly system comprises two male parts (two tabs extending over the height H) and two female parts (two interlocking grooves of complementary shape extending over the height H) on the transverse faces 13, 14 of the construction element 1 having the same substantially trapezoidal section shape.

[0057] The male parts and the female parts are able to cooperate respectively with the female parts and the male parts of the adjacent construction element 1. The stability of the assembly of the construction elements between them is ensured by the vertical male and female interlockings located at the ends of the block.

[0058] The construction element of the invention is suitable for different types of construction, such as for example individual houses and collective housing.

[0059] Of course, the present invention is not limited to the examples and embodiments described and shown because various modifications can be made thereto without departing from its scope. The shape of the building block is not limited to that illustrated in the embodiments described previously. Other shapes can indeed be envisaged. Several recesses can be provided in the framework and several distinct mixtures comprising at least one bio-sourced material can be inserted therein.

Claims

Claims

1. Construction element (1) comprising a concrete structure of generally rectangular parallelepiped shape having two substantially planar longitudinal faces (11, 12), two transverse faces (13, 14) connecting the longitudinal faces (11, 12), an upper face and a lower face which are substantially planar, characterized in that said structure comprises at least one internal cell (15) opening on only one of the upper and lower faces of the construction element or on both the upper (15) and lower faces, said at least one internal cell (15) being filled with a mixture in the form of a paste comprising at least: - a bio-sourced material being wood in the form of sawdust or shavings, and - a binder comprising a mixture of sulfo-aluminous cement, slag, clinker, fly ash, pozzolans and water.

2. Construction element according to claim 1, characterized in that said at least one bio-sourced material is a residue from agricultural or forestry operations, or comes from recycling.

3. Construction element (1) according to claim 1 or 2, the mass proportion of wood in the mixture being between 30 and 90%.

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