FR2713686A1 - Method of bonding between a bituminous layer and a thermal insulator. - Google Patents

Abstract

In a roof coating, a bituminous layer (2) is bonded to a heat insulation layer (3) by means of a hydraulic binder.

Description

Method of bonding between a bituminous layer and a thermal insulator
The present invention relates to a method of bonding between a sealing layer and a thermal insulation layer and between several sealing or thermal insulation layers.

It is known in the building to install a bituminous layer on which there is then a thermal insulator.

Such a system is commonly used in particular for achieving the tightness of masonry roofs. The coating usually comprises the following layers - a vapor barrier based on oxidized bitumen, in particular a bituminous felt of the type known under the reference 36 S, or else based on polymer bitumen, in particular elastomeric and plastomeric coatings (type SBS or APP); - a layer of thermally insulating material, in particular of polyurethane foam, expanded polystyrene, perlite or mineral wool; - A modified bitumen waterproofing layer which can be protected in particular by a metal sheet and / or held in place by an aggregate deposit or by a metal sheet.

In what follows, the term "layer" does not designate each of the homogeneous elementary layers making up the finished coating, but the various laminar components used on the site for the realization thereof, which can themselves be composed of several layers. elementary.

Traditionally, the above layers are joined together by hot-coated bitumen.

Bitumen melting and hot spreading operations are painful and present risks of burns and ignition because fusion requires the presence on the site of a melter.

There are also cold adhesives based on polyurethane or bitumen for this application, but these adhesives contain solvents which make them restrictive from the point of view of hygiene and safety, or even the quality of the bonding.

The object of the invention is to eliminate these drawbacks of the known method.

To this end, the invention relates to a process for linking several layers, characterized in that the binder used is a hydraulic binder comprising at least - a cement 100 to 400 parts (by weight) - a filler 200 to 500 parts ( by weight) - a superplasticizer, this hydraulic binder being mixed with water in a proportion by weight of 150 to 450 parts per 600 parts of binder.

Although there is a great variety of hydraulic binders, used in particular in building and public works, none of those known until now has been found suitable for bonding a layer based on bitumen and a thermally insulating layer. Surprisingly, the hydraulic binder used in the process according to the invention makes it possible to adhere the insulating layers not only to the bitumen, but also to various other materials capable of constituting the face of the sealing layer facing the insulating layer.

A colloid can also be added to these components.

Amino derivatives can also be added to improve the adhesiveness with certain bitumens.

According to the invention, the cement is either a pure cement of the type
CPA (Portland Portland Artificial Cement) or a cement comprising a secondary constituent, that is to say - CPJ type (Portland cement with Additions), - or CHF type (Hauts-Fourneaux cement), - or CLK type (Dairy cement with Clinker), - or CLC type (Cement with Dairy and Ash).

The filler can be of your choice - crushed limestone filler, - siliceous filler, - fly ash, - ground slag, - ground pozzolan - silica smoke.

When the cement used contains a secondary component, the filler content of the binder which is the subject of the invention is adjusted to take account of the supply of secondary components due to the cement.

Cement and filler are the usual hydraulic constituents which allow insulation-bitumen adhesion, but used alone they would not give a satisfactory result.

It is indeed necessary to prevent that the quantity of water used does not decrease the thermal performances of the insulator or does not cause any disorder in the system.

But at the same time it is necessary both to obtain a consistency allowing easy spreading without the spreading manipulations (using a trowel or a squeegee) causing separation of the water and the hydraulic binder.

It is to obtain this result that a superplasticizer adjuvant is used.

This superplasticizer can be - a sulfonated formaldehyde melamine, - a sulfonated formaldehyde naphthalene, - an acrylic copolymer, - a vinylester copolymer, - sodium saccharates or carbohydrates, - polyhydroxycarboxylic acids, - lignosulfonates.

This superplasticizer is added in the proportion of 0.1 to 1% of the cement (content expressed as dry extract).

This result is further improved by adding a water-retaining adjuvant which will increase the stability, thixotropy and insensitivity of the material vis-à-vis possible variations in the dosage of water.

This water-retaining adjuvant is, according to the invention, a colloid which can be chosen from the following products - colloidal clay, - methylcellulose or hydroxymethylcellulose, - stearates, - alginates, - casein, - polyvinyl acetate, - welan gums, - xanthan gums.

This colloid is added to the portion of 0.1 to 1% of the cement (content expressed as dry extract).

 It also turns out that the combination of a superplasticizer and a colloid is advantageous because the deflocculating power of the superplasticizer makes it possible to increase the dispersion of the colloid, the latter inhibiting the phenomenon of bleeding.

The amino derivative is, according to the invention, chosen from the following products - polyamines and derivatives, - tallow dipropylene triamine and derivatives, - alkyl-amido imidazo polyamines and derivatives, - fatty amines and derivatives, including quaternary ammonium salts.

This amino derivative is used in a proportion of 0.01 to 0.1% by weight (content expressed as dry extract).

According to the invention, this composition with three cement elements + filler + superplasticizer, or else with four elements if a colloid is added, or else with five elements if an amino derivative is added, can be adapted according to the conditions on site temperature by incorporating a setting retarder in hot weather (ambient outside temperature of around 40 "C and substrate temperature up to 80" C) or by incorporating a setting accelerator in cold weather (temperature of the order of 00C and even lower).

The setting accelerators are the following adjuvants - calcium or sodium chloride, - alkaline bases, - sodium nitrate, borates and thiosulfate.

The setting retarders are the following adjuvants - hydroxycarboxylic acids, - oxalic acids, gluconic, - sodium and calcium phosphates and gluconates, - sucrose, glucose, - lignosulfonates.

The manufacture of the paste from the binder is carried out directly on the site by kneading said binder with water, the amount of water possibly being between 150 and 450 parts per 600 parts of binder (by weight). This fork allows in particular the installation of the insulation on a vapor barrier already wet (by rain for example).

This hydraulic binder has multiple advantages over all known binders or glues - on-site manufacturing by simple mixing, - cold manufacturing without the need for burners, - manufacturing achievable in a wide range of outside temperatures (0 to 40 "C), - spreading of the product with an easy rubber squeegee because of its smoothness and its thixotropy, - constant maintenance of this unctuous state (or of rheology) for one hour, - method of positioning allowing work to progress , - laborious work without any problem of toxicity and safety (no vapor, no heating, no toxic vapors), - possible implementation of the binder on a slightly wet bituminous support, - absence of bleeding when the binder is mixed with the proportion of water indicated, - almost instantaneous adhesion of the insulating panel to the bituminous vapor barrier with the possibility of slightly moving the panel during approximately thirty minutes, which enables installation faults to be corrected, - possibility of circulating on the insulating panels as soon as they are put in place, - tear resistance greater than that of the insulators.

And to all these advantages concerning the ease of installation, it should be added that this product does not release toxic vapor in the event of fire and is non-combustible.

Obviously, the invention is not limited to the example described above concerning the laying of an insulating layer of rock wool on a bituminous vapor barrier.

It provides in particular the following possibilities - The first and second layers are respectively an insulating layer and an outer sealing layer.

- The first and second layers are respectively a vapor barrier and an insulating layer on which is fixed by the same binder an outer sealing layer.

- The first and second layers are both insulating layers.

- The waterproofing layer is based on bitumen.

- The sealing layer has an aluminum sheet on its face to stick to the insulating layer.

- The insulating layer is based on a material chosen from plastic foams, in particular polystyrene or polyurethane, perlite and mineral wools, in particular rock wool.

The characteristics and advantages of the invention will be explained in more detail in the description below, with reference to the accompanying drawing, the single figure of which is a partial perspective view of a waterproofing coating in progress, using the method according to the invention.

The figure shows a roofing masonry 1 on which a waterproofing and thermal insulation coating is being produced. This covering comprises a vapor barrier 2 constituted by a bituminous felt of type 36 S applied to the masonry 1, and on which must be glued insulating panels 3, for example of rock wool. To carry out this bonding, a binder in the pasty state is prepared by kneading with water in the proportions indicated.

The binder is spread uniformly on the screen 2, by means of a squeegee or the like, at a rate of approximately 4 kg per square meter to obtain a film 4 with a thickness of 2 mm. The panels 3 can be placed immediately on this binder film.

Another similar binder film can then be formed on the upper surface of the panels 3 for bonding an external sealing layer, not shown, for example based on modified bitumen.

Claims (18)

Claims 1. Method of mutual bonding of a bituminous layer (2) and a thermally insulating layer (3) for the production of a waterproofing and insulation coating in the field of building and public works, in which , after having put in place a first (2) of said layers on site, a binder (4) is applied to it in a pasty state which is in turn covered by the second layer (3), characterized in that said binder is based on a hydraulic binder consisting essentially of the following products - cement 100 to 400 parts (by weight) - filler 200 to 500 parts (by weight) - superplasticizer 0.1% to 1% relative to the cement. 2. Method according to claim 1, in which a colloid is added to the binder in the proportion of 0.1% to 1% of the cement. 3. Method according to claim 2, in which the colloid is chosen from the following products - colloidal clay, - methylcellulose or hydroxymethylcellulose, - stearates, - alginates, - casein, - polyvinyl acetate, - welan gums, - xanthan gums. 4. Method according to one of the preceding claims, in which an amino derivative is added in the proportion of 0.01% to 0.1% of the cement. 5. Method according to claim 4, in which the amino derivative is chosen from the following products - polyamines and derivatives, - tallow dipropylene triamine and derivatives, - alkylamido imidazo polyamines and derivatives, - fatty amines and derivatives, including salts of 'quaternary ammonium. 6. Method according to one of the preceding claims, in which a setting retarder is added when the outside temperature is high. 7. The method of claim 6, wherein the setting retarder is chosen from the following products - hydroxycarboxylic acids, - oxalic acids, gluconic, - sodium and calcium phosphates and gluconates, - sucrose, glucose, - lignosulfonates. 8. Method according to one of claims 1 to 5, wherein a setting accelerator is added when the outside temperature is low. 9. The method of claim 8, wherein the setting accelerator is chosen from the following products - calcium or sodium chloride, - alkaline bases, - sodium nitrate, borates or thiosulfate. 10. Method according to one of the preceding claims, in which the cement is chosen from the following cements - CPJ type, - CPA type, - CHF type, - CLK type, - CLC type. 11. Method according to one of the preceding claims, in which the filler is chosen from the following products - ground limestone filler, - siliceous filler, - fly ash, - ground slag, - ground pozzolan - silica smoke. 12. Method according to one of the preceding claims, in which the superplasticizer is chosen from the following products - sulfonated melanin formaldehyde, - sulfonated naphthalene formaldehyde, - acrylic copolymer, - vinylester copolymer, - sodium saccharates or carbohydrates, - polyhydroxycarboxylic acids, - lignosulfonates. 13. Method according to any one of the preceding claims, according to which the binder is mixed on site in order to obtain a paste, the quantity of water possibly being between 150 and 450 parts per 600 parts of binder (in weight). 14. Method according to one of the preceding claims, characterized in that the first and second layers are respectively a vapor barrier screen (2) and an insulating layer (3). 15. Method according to one of claims 1 to 13, characterized in that the first and second layers are each an insulating layer. 16. Method according to any one of claims 1 to 13, characterized in that the first and second layers are respectively a vapor barrier screen covered above with an aluminum face and an insulating layer. 17. Method according to one of the preceding claims, characterized in that the sealing layer comprises an aluminum sheet on its face to be bonded to the insulating layer. 18. Method according to one of the preceding claims, characterized in that the insulating layer (3) is based on a material chosen from plastic foams, in particular polystyrene or polyurethane, perlite and mineral wools, in particular the Rockwool.