EP2644341B1

EP2644341B1 - Method for manufacturing a reflective construction element.

Info

Publication number: EP2644341B1
Application number: EP13160494.4A
Authority: EP
Inventors: Willy Meirlaen
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-03-26
Filing date: 2013-03-21
Publication date: 2021-05-26
Anticipated expiration: 2033-03-21
Also published as: EP2644341A1; BE1020502A3

Description

The present invention concerns a method for manufacturing a reflective construction element.
The reflective construction element may for example be a reflective paving element such as a reflective concrete clinker or a reflective pavement.
Although concrete clinkers are mainly referred to here, it is clear that the reflective construction element can be any construction element whatsoever which is used as a part or a building stone of a speed bump or any other part to be highlighted in constructions or road constructions, on public roads and motorways and/or in private infrastructure works.
The reflective construction element may be a prefabricated construction element or it may be built on the construction site.
Moreover, the reflective construction element can also be made of plastic.
A known method for manufacturing a concrete clinker to be visually highlighted consists in taking an ordinary construction element as a basis, and providing this construction element with a white or coloured layer, usually after it has been placed.
A known method consists more particularly in scattering glass beads or micro glass beads on a freshly applied layer of paint.
Such micro glass beads concern spherical and translucent particles intended to ensure the night visibility of road markings by retroflection of incident light beams from vehicle lights towards the driver.
A glass bead which settles in the paint by 60% and protrudes from the paint by 40% is considered to be an ideally applied glass bead.
Often, mixtures of micro glass beads and roughening granules are provided on the road markings.
A disadvantage of this known method is that it is labourintensive and that the adhesion of the reflective layer to the construction element has limitations.
US-B-6616874 discloses a method of manufacture of a reflective construction element.
Another known method for manufacturing a concrete clinker to be visually highlighted consists in providing a mould, in putting a wet or moist mixture in it, which mixture contains gid, for example white marble grid, water and cement, for example white cement, and sand, and in subsequently filling the mould with concrete which is then vibrated or compressed.
A disadvantage of this known method is that the reflective qualities are restricted.
The present invention aims to remedy one or several of the above-mentioned and other disadvantages and/or to provide an alternative method for manufacturing a reflective construction element.
To this end, the present invention concerns a method for manufacturing a reflective construction element as defined in claim 1.
According to a practical variant of the embodiment, this method for manufacturing a reflective construction element which, starting rom a mould or the like, comprises the steps of providing a mainly dry film which contains glass beads, providing a wet mixture on the latter which contains at least cement, water, and sand and/or grit and/or another grain material, and applying the concrete or plastic or another material on the latter which forms the structural part of the construction element.
According to a preferred variant of the embodiment, the dry film also contains roughening particles or roughening means, such that the dry layer contains between 70% and 80% of glass beads and between 30% and 20% of roughening particles or roughening means respectively.
A practical composition for the dry film is a mixture of three parts by volume of glass beads having diameters between 125 µm and 850 µm and larger if necessary, and one part by volume of broken glass particles with the largest diameter between 250 µm and 850 µm as roughening means.
According to a preferred variant of the embodiment, also the wet film contains glass beads and/or roughening particles or roughening means.
By dry film glass beads, possibly mixed with roughening particles or roughening means, are meant a layer of such particles without any binders or with less than 50% of the volume of binders which is provided in the wet film.
A major advantage which is obtained by applying the method according to the invention is that the glass beads, which provide for an optimal retro-reflective power, have an immediate effect as they are mainly applied in a dry manner.
Indeed, the mainly dry coated layer will be partially penetrated by the binder, in the practical embodiment by the wet or humidly coated layer, whereby the cement and the water or any other binder serve as a binder.
The dry glass beads are bound, whereby a large part of the bound glass beads retain an uncoated side, however.
A glass bead which settles in the binder mass by 60% and protrudes from the latter by 40% is considered to be an ideally applied glass bead.
Naturally, the degree of settling in de binder mass will not be even. A large quantity of glass beads will not even be bound and will be recycled after the construction element is removed from the mould.
A possible post-processing can detach the glass beads which are only bound to a limited extend for re-use.
According to a preferred embodiment, the dry film glass beads are applied in a layer having a thickness of 1 to 2 millimetre, whereas the layer of the wet mixture has a thickness of for example 10 millimetre.
The concrete or the plastic or the other material which forms the structural part of the construction element preferably has a colour which is adapted to the desired appearance and composition of the wet film.
The wet film may contain for example four parts by volume of white cement, one part by volume of white sand, two parts by volume of water or according to need, and possibly also one part by volume of titanium dioxide when an intense white colour is desired.
As mentioned above, the wet film may also contain glass beads, for example three parts by volume of glass beads having diameters between 125 µm and 850 µm to be added to the last-mentioned composition, and possibly additionally also one part by volume of broken glass particles with the largest diameter between 250 µm and 850 µm as roughening means.
It is clear that also other pigments can be used where other colours are envisaged.
Moreover, the dry film and/or the wet film may also include other similar inert materials as roughening means.
The obtained reflective top layer will have the desired reflective qualities immediately after the manufacturing of the construction element.
As stated earlier, the dry film preferably contains a mixture of glass beads having different dimensions in view of a proper penetration of the wet film.
A mix of beads with diameters between 125 µm and 850 µm will entail a proper penetration.
Optionally, the glass beads are mixed with grains of sand or the like.
It is clear that some things will have to be adapted to the composition of the wet film and also to the possible vibration and/or compression following the application of the wet film and/or following the application of the concrete or the plastic or the other material which forms the structural part of the construction element.

Claims

Method for manufacturing a reflective construction element which method, starting from a mould, comprises the steps of providing therein a mainly unbound or what is called a dry film which contains reflective particles, and providing thereon a binding layer or what is called a wet film and applying thereon a material which forms the structural part of the construction element, whereby the wet film comprises glass beads and/or roughening particles or roughening means and in that the unbound or what is called the dry film comprises glass beads whereby the glass beads concern a mixture of glass beads having diameters between 125 µm and 850 µm.
Method according to claim 1, characterised in that the dry film also contains roughening particles or roughening means, in such a proportion that the dry film contains between 70% and 80% of glass beads and between 30% and 20% of roughening particles or roughening means respectively.
Method according to claim 2, characterised in that the dry film contains, per three parts by volume of glass beads, between a half part by volume and two parts by volume of roughening particles or roughening means, whose largest diameter is situated between 250 µm and 850 µm.
Method according to one or several of the preceding claims, characterised in that the binding layer or what is called the wet film concerns a wet mixture comprising cement and water, and sand and/or grit and/or another granular material.
Method according to one or several of the preceding claims, characterised in that the wet film comprises titanium dioxide.
Method according to one or several of the preceding claims, characterised in that the wet film comprises, per four parts by volume of cement, mainly one part by volume of sand, two parts by volume of water or an amount according to need, mainly one part by volume of titanium dioxide, between two and four parts by volume of glass beads having diameters between 125 µm and 850 µm, and between a half and two parts by volume of broken glass particles with the largest diameter between 250 µm and 850 µm as roughening means.
Method according to one or several of the preceding claims, characterised in that the material which forms the structural part of the construction element is concrete or plastic.
Method according to one or several of the preceding claims, characterised in that the mainly unbound or what is called the dry film of reflective particles has a thickness of at least 1 millimetre.
Method according to one or several of the preceding claims, characterised in that the mainly unbound or what is called the dry film of reflective particles has a thickness of at least 2 millimetre.
Method according to one or several of the preceding claims, characterised in that the binding layer has a thickness of at least 5 millimetre.
Method according to one or several of the preceding claims, characterised in that the binding layer has a thickness of at least 8 millimetre.
Method according to one or several of the preceding claims, characterised in that the mould is vibrated and/or compressed before and/or after the application of the material which forms the structural part of the construction element and which is made of concrete or plastic.