LU85995A1 - NOVEL MORTAR COMPOSITION, PROCESS FOR IMPLEMENTING SAME AND DEVICE THEREFOR - Google Patents

Description

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* NEW COMPOSITION OF MORTAR, PROCESS FOR THE IMPLEMENTATION THEREOF AND DEVICE THEREFOR ^ The present invention relates to a new composition of mortar containing an organic binder and 05 inert fillers; it also relates to a method of using said new type mortar, as well as to a device for using such a composition.

Various resinous concretes are known which have been developed for decorative or construction elements affecting in particular particular surface aspects and allowing the most varied colors. These compositions are however not suitable for use in the construction or repair of buildings by a process known as gunning, in which said mortar is sprayed under pressure on the support to be covered over a desired layer thickness. This technique is already well known and allows considerable time savings for the implementation of the mortar since it no longer requires formwork or other support means.

The aim of the present invention is to provide a new mortar composition having interesting properties, intended for the construction or for the repair of concrete slabs, concrete coverings and the like, by a gunning process.

Another object of the present invention is to provide a new quick-setting mortar composition which allows accelerated implementation and which requires practically no more formwork.

The invention also aims to provide a method for using the above-mentioned composition.

Finally, the invention aims to provide a projection device forming part of the gunning apparatus which allows the implementation by gunning of the mor-35 tier according to the invention and which also allows I obtaining a particularly smooth and smooth surface finish.

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According to a first aspect of the invention, the mortar composition comprises at least inert fillers, a liquid epoxy resin of the oligomer type and a crosslinking hardener of the modified polyamide type.

05 Advantageously, the inert fillers consist of quartz with a high content of S1O2, of at least 98%, previously crushed and calibrated, washed with acid and then calcined.

The particle size is of the double-coating type, sometimes qualified as replenishment of the binder. The binder is a resin. liquid diepoxy crosslinked by a hardener of the modified polyamide type, reacting at normal temperature, that is to say between 5 and 25 ° C. The reaction of the two partners forms a continuous coating matrix. During the binder-filler mixture, the reactive partners coat the grains and trap them in a hardening system and a more per- hard material, forming than concrete.

The liquid diepoxy resin is of the oligomer type and advantageously has a viscosity of the order of 1000 mPa.s. at 25 ° C; it is preferably of a non-crystallizing nature. The hardener advantageously consists of a modified amine of the cycloaliphatic type with very low viscosity and is added to the resin in an amount of approximately 40% by weight. ---

Advantageously, the quartz binder ratio can vary between 1 to 5 and 1 to 20, depending on the particular applications and the goals sought.

The composition according to the invention has very advantageous properties and avoids many inconveniences. disadvantages compared to the conventional mortar compositions used up to now. By way of example, an adhesion to conventional concrete may be cited which is greater than its cohesion, high adhesion to steel, rapid hardening and without significant shrinkage, high re-resistance in compression and even in traction.

Y * According to another aspect of the present invention, -; 3 this provides a process for the preparation of the new mortar composition, from which the inert fillers are drawn by means of a pressurized fluid, the pulsed fillers are wetted, by spraying the liquid diepoxy resin playing the role of binder in combination with the hardener at the outlet of a spray head and the mixture thus obtained is projected at very high speed onto the support to be covered, in at least one layer.

Preferably, the inert fillers are subjected to turbulence movements by lateral injection of pressurized fluid in the trajectory of said mineral fillers transported under pressure, before injection of the resin and the hardener. It is obvious that the binder (resin plus hardener) can be sprayed in proportion proportioned on the moving filler particles.

Advantageously, the pressurized fluid is compressed air.

The use of the composition according to the invention makes it possible to obtain a very resistant coating and having an acceptable surface appearance. This can be further increased by using a spray head according to the invention which ensures a high-performance mixture and the most uniform possible distribution of the material projected onto the surface to be covered. According to the invention, the projection head consists of a divergent nozzle, the short side of which has an essentially circular opening adapted to the supply conduit 30 for inert filler materials and the long side of which has an essentially rectangular opening which is relatively long but whose height is less than the diameter of the opening of the short side, the lateral sides of said divergent nozzle being constituted by two 35 arcs of consecutive circles joining at mid-length of J!) said nozzle by forming a point d 'inflection, the arc of £ circle adjacent to the intake opening being concave Λ *' 1: ./ · '' '¥ "" & βί "Α ·'.

Λ · · - · »- · -— 4 and the circular arc adjacent to the essentially rectangular outlet opening being convex, the upper and lower surfaces of said divergent nozzle also being constituted by two arcs of circles consêcu-05 tifs joining mid-length of said nozzle by forming an inflection point, the arc of a circle adjacent to the; inlet inlet being convex and the arc of a circle adjacent to the outlet opening being concave, said nozzle being provided with at least two sprayers each arranged on the opposite faces of the nozzle.

Advantageously, the nozzle has two sprayers, the first of which is situated on the upper face and the other on the lower face of the latter.

Preferably, said sprayers are adjustable in direction so as to be able to adjust the jet of binder or resin as a function of the jet of particles of filler material.

In order to further improve the uniform distribution of the projected composition, the essentially rectangular outlet opening has a slight narrowing in the middle.

Said projection head can be made of composite material or of steel or of cast iron with high resistance T in particular to abrasion and can be produced by molding or shaping and welding.

Thanks to the use of the projection head according to the present invention, a uniform speed of the material jet is obtained and, therefore, a better distribution of the material over the entire exit section. Furthermore, it has been found that the particular shape of the projection head prevents a segregation of the fillers in the jet, which would result from differential speeds, and consequently a homogeneous composition is obtained at the outlet of said projection head.

I The invention is described in more detail below, ^ jf in support of the appended figures in which;

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5 - Figure 1 is a plan view of the projection head * according to the invention; - Figure 2 is a side view of the projection head according to the invention; and 05 - Figure 3 is a front view thereof.

With reference to the figures, the projection head 1 connected to a projection gun (not shown) assumes the shape of a divergent nozzle which starts from a circular section 3 to arrive at an outlet section 10 which is essentially rectangular or oblong 5. The inert filler materials are subjected to turbulence upstream of the barrel, which entrains the particles transported at high speed by rotating air under pressure. This turbulence can advantageously be created by a lateral injection of air into helical grooves. The upper 9 and lower 11 faces of said = nozzle are formed by two arcs of consecutive circles (FIG. 2) which join at an inflection point 7 disposed at mid-length of said nozzle. The circular arc 20 adjacent to the circular inlet opening 3 is convex and the second circular arc adjacent to the outlet opening 5 is concave. The lateral sides 13, 15 are also constituted by two consecutive arcs of circle which join at an inflection point arranged at mid-length of the nozzle. The circular arc adjacent to the inlet opening 3 is concave and that which is adjacent to the outlet opening is convex.

The projection head according to the invention comprises. at least two sprayers adjustable in their direc-tion, arranged in the immediate vicinity of the opening of * outlet 5, on the upper and lower faces (the sprayers are not shown in the figures). This advantageous arrangement of the sprayers prevents hardening of the composition in the barrel 35 or in the projection head and, consequently, a blockage thereof.

j In order to further improve the uniform distribution À "'ri *' 'l -i 6 * * of the material over the entire outlet section 5 and to promote uniformity, said outlet section 5 is slightly narrowed in the middle.

The inert fillers advantageously consist of ground quartz particles having an S1O2 content greater than 98%, washed with acid and calcined.

The binder sprayed in proportions dosed on the particles of inert filler, at the outlet of the spray head, consists of an oligomeric diepoxy resin having a viscosity of approximately 1000 mPa.s. at 25 ° C, added with a crosslinking hardener of the modified cycloaliphatic amine type with very low viscosity.

On a support, whether prepared or not, a first fluid layer having zero thixotropy is projected by means of the device according to the invention and then a viscous layer having an approximate thixotropy of 10. One or more layers of the composition according to the invention while respecting a pro-20 binder-quartz portion ranging from 1/5 to 1/10.

The composition according to the invention has a high reactivity and hardens in a time of the order of 20 minutes for 150 g of mixture, at 25 ° C.

Some advantageous properties of the composition according to the invention are summarized below: - adhesion to conventional concrete greater than the cohesion of conventional concrete; - high adhesion to steel (* 3.5 N / mm ^); - rapid hardening (4 to 24 hours depending on the case), resulting in time savings and better profitability * during processing; - hardening without shrinkage (therefore without tension in the adhesion plane and, as a result, better stability); - high mechanical strength (real) in compression; 35 - high internal cohesion due to a high tensile strength ranging from 5 to 20 N / mm ^; yL - high chemical stability; i - · <~ '·! i Λ water: .c, κ. tm ,; speed dV ^ éyctioA.- - thickear --2 lay of. pu c.f ccî-e: thinner (ie its ·? - ·. · 3 éai ictéristiques) superior y 05 - a protection by cover r-certI ~ ce feue ν · ρι, ο · - ·; ·. ion to rap irt.ci ·· u2 V ·: ·: - · s);

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Claims (11)

8 * 1. Mortar composition characterized in that it comprises at least inert fillers, a diepoxide liquid resin of the oligomer type and a crosslinking hardener 05 of the modified polyamine type. 2. Composition according to claim 1 characterized in that the inert fillers are quartz particles with a high content of S1O2, namely greater than 98%, crushed and graded, washed with acid and then calcined. 3. Composition according to claim 1 or 2 characterized in that the diepoxide liquid resin has a viscosity of the order of 1000 mPa.s. at 25 ° C and is non-crystallizing. '' 4. Composition according to any one of the preceding claims, characterized in that the content of hardener in the resin is of the order of 40% by weight. 5. Composition according to any one of the preceding claims, characterized in that the binder-quartz ratio is between l / 5 and 1/10. 6. Process for the preparation of the mortar composition according to any one of the preceding claims, characterized in that the inert fillers are drawn by means of a pressurized fluid, the pulsed fillers are wetted by spraying the resin diepoxide liquid acting as a binder in combination with the hardener at the outlet of a spray head and the mixture thus obtained is projected at very high speed onto the support to be covered, in at least one layer. 7. Method according to claim 6 characterized in that the inert filler particles are subjected to turbulence movements by lateral injection of pressurized fluid in the trajectory of said inert char-Ies transported under pressure, before injection. Ί tion of resin and hardener. Vi / ri! "·; ' VfÎ1 w + 4 ... 9 8. Method according to claim 6 or 7 characterized in that the pressurized fluid is compressed air v. 9. Method according to any one of the claims 5 to 5 6 to 8 characterized in that a first layer of relatively fluid composition is projected having a zero thixotropy and then a viscous layer having a thixotropy of about 10 and then optionally a or several layers of the composition in which the binder-quartz ratio is between 1/5 and 1/10. 10. Device for implementing the method according to any one of claims 6 to 9 characterized in that it consists of a divergent nozzle (l) the short side of which has an essentially circular opening (3) adapted to the feedstock supply conduit, the long side of which has a; , „Essentially rectangular or oblong opening (5) relatively long but whose height is less than the diameter of the opening of the short side (3), the> 20 lateral sides (13,15) of said diverging nozzle (l) being formed by two arcs of consecutive circles joining at mid-length of said nozzle by forming a point of inflection (7), the arc of a circle adjacent to the opening *, of intake (3) being concave and the arc of a circle adjja-25 cent at the essentially rectangular or oblong outlet opening (5) being convex, the upper (9) and lower (11) faces of said diverging nozzle also being constituted by two arcs of consecutive circles joining at mid-length of said nozzle by forming a point of inflection (7), the arc of circle adjja-. cent at the inlet opening (3) being convex and the arc of a circle adjacent to the outlet opening (5) being concave, said nozzle being provided, in the immediate vicinity of the outlet, at least two dis-35 sprayers each placed on the opposite faces (9,11) of the nozzle. 11. Device according to claim 10, characterized in that the sprayers are adjustable in 10. rection, 12 Device according to claim 10 or 11 characterized in that the essentially rectangular or oblong outlet opening (5) has a slight dreaming 05 in the middle. 1 7 ^ · * T t