CONCRETE COMPOSITION FOR PREFABRICATED OR CAST ELEMENTS

Abstract

The invention relates to a concrete composition, for example for a prefabricated or cast element, comprising at least one hydraulic binder and an aggregate, characterized in that the aggregate comprises, by mass relative to the total mass of the composition, at least 10 to 70% of glass debris, the glass debris containing exclusively essentially reflective glass debris having at least one metallized or enameled surface.

Description

Title of the invention: CONCRETE COMPOSITION FOR PREFABRICATED OR CAST ELEMENT TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of concrete elements, in particular prefabricated or cast elements, such as safety and / or signaling elements related to traffic lanes or decorative elements having enhanced optical properties, such as reflective and / or sparkling properties.

[0002] It relates more particularly to a concrete composition, for example for a prefabricated or cast element, and a concrete element formed from such a composition.

[0003] The invention also relates to a use of such a composition for the production of prefabricated elements such as road or sidewalk borders, quayside borders, foundations, paving stones or signaling elements, or cast elements such as slabs, screeds or surface coverings. STATE OF THE ART

[0004] In matters of road safety, to draw the attention of a user, motorist or pedestrian, to possible dangers, or quite simply to guide them, it is customary to highlight certain traffic lanes, safety elements and / or signs related to the traffic lanes.

[0005] For this purpose, conventionally, paints or marking strips deposited on the surface of the roadway or on safety and / or signaling elements have been widely used. In particular, paints or marking strips of a reflective nature, containing for example glass microbeads, have been widely used.

[0006] Another known solution for improving the visibility of a roadway consists of making road surfaces reflective by incorporating essentially reflective glass debris. Document FR 2770213 describes, for example, a road surface material or safety element material comprising from 10 to 80% by weight of glass debris, which comprises a mixture of essentially reflective glass debris, such as mirror-type glass debris, building glass debris or automotive glazing glass debris, and ordinary bottle-type or window-type glass debris, with essentially reflective glass debris representing between 30% and 50% of the glass debris.

[0007] However, this solution does not allow satisfactory reflective properties to be achieved, particularly in very poorly lit sites. Statement of the invention

[0008] The present invention aims to remedy all or part of the drawbacks of the state of the art cited above.

[0009] In particular, the invention relates to a concrete composition, for example for a prefabricated or cast concrete element, comprising at least one hydraulic binder and an aggregate, characterized in that the aggregate comprises, by mass relative to the total mass of the composition, at least 10 to 70% of glass debris, the glass debris containing exclusively essentially reflective glass debris having at least one metallized or enameled surface.

[0010] The integration of reflective glass debris into a composition for a concrete element gives the latter reflective or sparkling properties, thus improving its visibility.

[0011] By "containing exclusively essentially reflective glass debris" is meant that the proportion of glass debris does not contain other types of glass debris, for example of the ordinary glass type or other.

[0012] By opting for a composition comprising exclusively essentially reflective glass debris, with a metallized or enameled surface, it is possible to give the concrete element a satisfactory reflective effect with a lower proportion of glass debris.

[0013] In other words, the exclusive use of essentially reflective glass debris maximizes the reflective effect while minimizing the quantity of glass debris required, which makes it possible to retain a significant proportion of conventional aggregates, such as sand or gravel, in favor of the glass debris and thus to obtain characteristics, such as workability, workability and mechanical strength, close to those of a composition for a concrete element, for example prefabricated or cast, devoid of glass debris.

[0014] The reflective properties considered according to the invention relate to the reflection of light in the visible range, in particular lighting light such as, for example, urban lighting, light emitted by motor vehicles or natural light.

[0015] The composition may be a self-compacting concrete composition.

[0016] The aggregate may comprise by mass relative to the total mass of the composition from 15% to 50% of glass debris.

[0017] The glass fragments may be mirror shards.

[0018] The glass debris may have a particle size less than or equal to 8 mm, that is to say between 0 mm and 8 mm.

[0019] The aggregate may comprise, by mass, relative to the total mass of the composition, from 10% to 55% of gravel.

[0020] Glass debris may contain in mass relative to the total mass of debris of glass between 55% and 90% of glass debris of a first particle size between 4 mm and 8 mm and glass debris of a second particle size less than 4 mm. It is understood that the glass debris of the second particle size can then represent between 10% and 45% by mass relative to the total mass of glass debris.

[0021] The glass debris of the second particle size can be used instead of a conventional substrate, in particular sand of the same particle size, namely between 0 mm and 4 mm.

[0022] The aggregate may comprise, by mass, relative to the total mass of the composition, from 5% to 35% of sand.

[0023] Alternatively, the glass debris may have a particle size less than or equal to 4 mm, i.e. between 0 mm and 4 mm. In other words, the glass debris may contain only glass debris having a particle size less than 4 mm.

[0024] The invention also relates to a concrete element, for example a prefabricated or cast element, formed from a composition as described above.

[0025] The concrete element can therefore be a prefabricated concrete element.

[0026] The precast concrete element can be manufactured using a conventional manufacturing process.

[0027] The precast concrete element may comprise a single-layer structure, i.e. it is formed entirely from the composition described above.

[0028] In particular, the method of manufacturing a prefabricated concrete element comprising a single-layer structure may comprise the following successive steps: • preparation of a concrete mixture comprising the composition as described above, water and concrete admixtures, • pouring said concrete mixture into a mold, • compacting said concrete mix, for example by vibration of the mold and / or by pressing in the mold, in particular by means of a conventional presser, • hardening of the concrete mix, and • demolding of the prefabricated concrete element.

[0029] The glass debris can be distributed homogeneously in the precast concrete element.

[0030] The prefabricated concrete element may comprise a two-layer structure, that is to say that it comprises at least two layers arranged one against the other: at least a first layer of concrete or mortar, called the structural layer, comprising a hydraulic binder, such as a cement, aggregates and optionally additives, and at least a second layer, called the facing layer, formed from the composition described above. above.

[0031] In particular, the method for manufacturing a prefabricated concrete element comprising a two-layer structure may comprise the following successive steps: • preparation of a first conventional concrete mix, for example free of glass debris, typically comprising a hydraulic binder, aggregates, water and concrete additives, • preparation of a second concrete mix comprising the composition as described above, water and concrete admixtures, • pouring the first concrete mix into the bottom of a mold so as to form a first layer called a facing layer, • compaction of the first facing layer by vibration of the mold and / or by pressing against the bottom of the mold, in particular using a conventional presser, • pouring the second into the mold, onto the first facing layer, so as to form a second so-called structural layer, • compaction of the second structural layer by vibration of the mold and / or by pressing against the first facing layer, • hardening of the first facing layer and the second structural layer, • demolding of the prefabricated concrete element.

[0032] The glass debris can be distributed evenly in the first facing layer.

[0033] The concrete element may be a cast concrete element.

[0034] The cast concrete element may be a slab, a screed or a surface covering, such as polished concrete.

[0035] Such a cast concrete element can be used for decorative purposes, for example as floor or wall covering.

[0036] The cast concrete element may be formed from a composition in which the glass debris has a grain size less than or equal to 4 mm, i.e. between 0 mm and 4 mm.

[0037] The cast concrete element may be formed from a composition in which the aggregate is free of sand.

[0038] The cast concrete element can be manufactured using a conventional manufacturing process.

[0039] In particular, the method of manufacturing a cast concrete element may comprise the following successive steps: • preparation of a concrete mixture comprising the composition as described above, water and concrete admixtures, • mixing the concrete mixture, for example using a conventional mixer, for a period of time customary in the field, until concrete of the desired fluidity is obtained, • pouring concrete, • hardening of concrete, and • possibly, finishing to remove a surface layer or prevent the appearance of such a layer, for example by sandblasting, shot blasting, high-pressure fluid projection, bush hammering or deactivation of the concrete.

[0040] The cast concrete element may be an extruded concrete element.

[0041] The extruded concrete element may be a road or sidewalk edge, a quay edge, a base, a paving stone or a signage element.

[0042] In particular, the method of manufacturing an extruded concrete element may comprise the following successive steps: • preparation of a concrete mixture comprising the composition as described above, water and concrete admixtures, • mixing the concrete mixture, for example using a conventional mixer, for a period of time customary in the field, until concrete of the desired fluidity is obtained, • extrusion of concrete by pushing or pulling the concrete through a predefined shape so as to form an extruded concrete element, • possibly, cutting of the extruded concrete element, • hardening of the extruded concrete element, • optionally, finishing to remove a surface layer or prevent the appearance of such a layer, for example by sandblasting, shot blasting, high-pressure fluid projection, bush hammering or deactivation of the concrete.

[0043] The invention finally relates to a use of the concrete composition as described above, for the production of prefabricated concrete elements such as road or sidewalk edges, quay edges, basements, paving stones or signage elements, or cast concrete elements such as slabs or screeds.

[0044] The invention finally relates to a use of the concrete composition in which the glass debris has a particle size less than or equal to 4 mm, for the production of cast concrete elements such as slabs, screeds or surface coverings. EXAMPLES

[0045] Example 1: Concrete for precast concrete elements comprising a single-layer structure.

[0046] The following concrete mix is prepared: • River gravel or crushed: 1000 kg • 0 / 4 alluvial or crushed sand: 500 kg • Mirror glass grain size 4 / 8: 400 kg • Water and additives: 120 kg • CPA 52.5 cement: 300 kg

[0047] A manufacturing method is implemented for a prefabricated concrete element comprising a single-layer structure.

[0048] Example 2: Concrete for precast concrete elements comprising a two-layer structure (facing layer)

[0049] The following concrete mix is prepared: • Sand 0 / 4: 470 kg • Sand 0 / 2: 350 kg • 4 / 10 limestone gravel: 600 kg • Mirror glass grain size 4 / 7: 400 kg • Water and additives: 120 kg • CPA CEM 2 52.5 CP2 cement: 300 kg

[0050] A manufacturing method is implemented for a prefabricated concrete element comprising a two-layer structure.

[0051] The mechanical resistance of a facing layer thus obtained may be lower than the mechanical resistance of a layer of a prefabricated concrete element comprising a single-layer structure given that it essentially provides an ornamental function.

[0052] Example 3: Concrete for precast concrete elements comprising a two-layer structure (facing layer): • Mirror glass grain size 0 / 4: 470 kg • Sand 0 / 2: 350 kg • 4 / 10 limestone gravel: 600 kg • Mirror glass grain size 4 / 7: 400 kg • Water and additives: 120 kg • CPA CEM 2 52.5 CP2 cement: 300 kg

[0053] A manufacturing method is implemented for a prefabricated concrete element comprising a two-layer structure.

[0054] Compared to Example 2, the 0 / 4 sand was replaced by essentially reflective glass debris, in particular mirror shards of a similar grain size, namely between 0 mm and 4 mm (0 / 4).

[0055] Advantageously, the glass debris with a grain size of 0 / 4 results from a glass crushing operation aimed at obtaining essentially reflective glass debris with a grain size of between 4 mm and 7 mm (4 / 7) or between 4 mm and 8 mm (4 / 8). This debris is thus reused in the manufacture of concrete and allows the reflective effect to be further improved, without significantly degrading the mechanical resistance.

[0056] The mechanical resistance of a facing layer thus obtained may be lower than the mechanical resistance of a layer of a prefabricated concrete element comprising a single-layer structure given that it essentially provides an ornamental function.

[0057] Example 4: Concrete called “ready-mix” for cast concrete elements: • Mirror glass grain size 0 / 4: 970 kg • 4 / 10 limestone gravel: 900 kg • Water and additives: 120 kg • CPA CEM 2 52.5 CP2 cement: 300 kg

[0058] A manufacturing process is implemented for a cast concrete element, for example extruded.

[0059] This concrete can be used for the production of screeds, slabs, or surface coverings, in order to improve visibility in very poorly lit sites and also to give an aesthetic appearance to these concrete elements.

Claims

Claims

1. Concrete composition, for example for a prefabricated or cast concrete element, comprising at least one hydraulic binder and an aggregate, characterized in that the aggregate comprises, by mass relative to the total mass of the composition, at least 10 to 70% of glass debris, the glass debris containing exclusively essentially reflective glass debris having at least one metallized or enameled surface.

2. Composition according to claim 1, characterized in that the aggregate comprises by mass relative to the total mass of the composition from 15% to 50% of glass debris.

3. Composition according to one of claims 1 or 2, characterized in that the glass debris is mirror shards.

4. Composition according to any one of claims 1 to 3, characterized in that the glass debris has a particle size less than or equal to 8 mm.

5. Composition according to any one of claims 1 to 4, characterized in that the aggregate comprises, by mass, relative to the total mass of the composition, from 10% to 55% of gravel.

6. Composition according to any one of claims 1 to 5, characterized in that the glass debris contains by mass relative to the total mass of glass debris between 55% and 90% of glass debris with a first particle size of between 4 mm and 8 mm and glass debris with a second particle size of less than 4 mm.

7. Composition according to any one of claims 1 to 6, characterized in that the aggregate comprises, by mass, relative to the total mass of the composition, from 5% to 35% of sand.

8. Composition according to any one of claims 1 to 5, characterized in that the glass debris has a particle size less than or equal to 4 mm.

9. A concrete element, for example for a precast or cast concrete element formed from a composition according to any one of claims 1 to 8.

10. Use of the concrete composition according to any one of claims 1 to 7, for the production of prefabricated concrete elements such as road or sidewalk borders, quayside borders, foundations, paving stones or signaling elements, or concrete elements cast such as slabs, screeds or surface coverings.

11. Use of the concrete composition according to claim 8, for the production of cast concrete elements such as slabs, screeds or surface coverings.