NL7906971A - Synthetic element for covering concrete - produced by pressing broken stone into unhardened synthetic surface - Google Patents

Abstract

Covering element for concrete is prepd. by casting a liq. synthetic material onto a plate or into a mould and allowing the synthetic to harden, and sprinkling broken stone over the unhardened synthetic during or after the casting. Pref. of the stones penetrate into the synthetic, whilst the rest extend out from the synthetic. Element bonds firmly to concrete and can be applied over a frontage. Element strengthens the concrete and provides protection against acids.

Description

- 1 - IT.O. 27815

Amerglass B.Y. in Oosterhout.

Short designation: Method for the production of a concrete cladding element and for the production of a concrete body clad with such an element.

In the first instance, the invention relates to a method for the production of a coating element for concrete, in which a plastic in the flowing state is poured on or in a plate or mold, after which the plastic turns into the solid state.

Attempts have been made in the past to coat concrete bodies with plastic sheets for aesthetic reasons and to protect against acids. These attempts were unsuccessful, especially since a firm bond between concrete and plastic sheet could not be achieved.

An attempt to manufacture a coated facade panel. 15 in which plastic plates were fitted with cast-on T-pieces, which were embedded in the concrete mortar, was not sufficient because this did not allow a tight facade plate to be achieved.

The object of the invention is to carry out the above-mentioned method for manufacturing concrete cladding elements, which results in a product which can adhere extremely firmly to the concrete to be coated and which can be applied tightly over a facade or the like.

In accordance with the invention, the method mentioned in the preamble is characterized for this purpose in that after or during the casting of the plastic crushed rock is sprinkled over the plastic which has not yet become solid, whereby care is taken that the pebbles have a part of their content in penetrate the plastic 79 0 6 S 7l -I- Λ 2 nd and the remainder out of plastic.

Preferably, the stones are pressed into the plastic for about half of their content.

Good results are achieved "when the stones are largely sized between 3 and 5 nrn. 5

The stones can be pressed into the cast viscous plastic using a roller.

In order to prevent the porosity of the protruding part of the pebbles from being destroyed by adhesion of plastic, before the roller is moved over the plastic, the surface of the plastic and the pebbles sprinkled thereon will be covered with tissue paper.

The stones preferably consist of a porous basalt grit.

The porosity of the stones is essential for bonding with the concrete.

It has been found that when the said basalt grit is used, the tensile strength and shear strength of the bond between the cladding plate and the concrete can be greater than the tensile strength and shear strength of the concrete itself. In fact, a cladding element anchored to a concrete body by the embedded protruding rock parts imparts to that concrete body the tensile strength it normally lacks for the most part. In addition, a plastic covering element provides good protection against acids. 25 "Many plastics - both thermoplastics and thermosets - are suitable for the production of a cladding element. Examples include the plastics ABS and PVC. Preferably, however, the plastic consists of a fiber-reinforced polyester resin. Bit material is easy to process. and strong fibers suitable for reinforcement are mainly glass fibers, but also synthetic fibers and asbestos fibers.

The invention also relates to a method for the manufacture of a concrete body, in which concrete mortar is poured into a formwork and cured.

This method is characterized in that before the casting of the hot spout against at least one of the walls of the formwork a coating element manufactured according to the above method is applied, the side with the projecting stones facing inwards. 5

For casting a curable polyester resin on or in a plate or mold, a known per se gun can be used, in which the following can be supplied separately: 1. polyester with an accelerator (for example cobalt naphthenate) 10 2. styrene or vinyl toluene with a catalyst (for example, a peroxide) and 3. a glass wire, which is cut into fibers in the gun.

The materials also leave the gun individually and are mixed on or in the mold, crosslinking the polyester and setting relatively quickly. Immediately after pouring, cleaning and dried basalt grit (bags 3 and 5 mm) are scattered over the hardening polyester. After spreading a sheet of blotting paper over the free surface of the polyester and 20 over the stones, the latter are half pressed into the polyester by means of a roller. The function of the blotting paper is to prevent the roller from coming into contact with a still liquid plastic, whereby the adhering plastic could then end up on the protruding rock parts. 25

The shear strength and tensile strength were determined on the basis of test pieces consisting of a concrete body and an attached polyester coating element.

To determine the shear strength, a concrete cube was provided on two opposite surfaces with cladding plates of glass fiber reinforced polyester resin manufactured according to the invention and attached to the concrete.

7906971

Claims (9)

1. A method of manufacturing a cladding element for concrete, in which a plastic in a flowing state is applied to it. or is poured into a plate or mold, after which the plastic turns into the solid state, characterized in that after or during the pouring of the plastic crushed rock is sprinkled over the plastic which has not yet become solid, whereby care is taken that the pebbles penetrate part of their contents into the plastic and the remaining part out of the plastic sign. 2. Method according to claim 1, characterized in that the pebbles are pressed into the plastic for about half of the content. 7906971 Method according to claim 1 or 2, characterized in that the pebbles largely have dimensions between 5 and 5 ™ di ". Method according to one of the preceding claims, characterized in that use is made of a roller for pressing the stones into the plastic. 5. Method according to claim 4, characterized in that, before the roller is moved over the plastic, the surface of the plastic and the stones sprinkled thereon are covered with tissue paper. 10 Method according to one of the preceding claims, characterized in that the stones consist of a porous basalt grit. 7. A method according to any one of the preceding claims, characterized in that the pebbles are cleaned and dried beforehand. Method according to one of the preceding claims, characterized in that the plastic consists of a fiber-reinforced polyester resin. 9. Method for the production of a concrete body, wherein the concrete mortar is poured into a formwork and cured, characterized in that before pouring the concrete mortar against at least one of the walls of the formwork, a one of the claims 1 to 8 made of the covering body is applied, wherein the side with the projecting stones is turned inwards. 7906971