DE1807252A1 - Polyacrylate or concrete treated with poly - acrylic acid and electrolyte - Google Patents

Abstract

Concrete units, particularly for lift-slab process, are provided with water-repellent film interfaces by treating, pref. by spraying set concrete surfaces with an aqs. polyacrylate or polyacrylic acid solutions as well as with a solution of an electrolyte, particularly an alkaline earth salt or hydroxide.

Description

Process for the production of a separating layer for the production of Concrete elements, in particular for the lift-slab method. The invention relates to a process for the production of a separating layer for the production of concrete elements, especially for the lift-slab method, in which several concrete elements are stacked on top of each other be made in such a way that on an already tied, carefully A separating layer is applied to the smoothed concrete surface and then on top of this Area is re-concreted. The separating layer prevents the two from sticking Concrete elements. This process can be repeated any number of times, each time The final concrete element is used as the shuttering base for the next element.

As a dry separating layer, wood wool panels are preferably used, Plastic sheeting, layers of clay improved with kakk and cement, stiff slabs of lesser ones Thickness, e.g.

made of hard PVC, hardboard with or without a water-repellent coating or made of sheet metal.

Oils, e.g. lubricating oils, waxes are used as liquid coatings or paraffinic solutions that are sprayed onto the concrete element as follows you can put on the concrete element rock powder1 graphite or similar fine-grain mineral Spread fabrics, creating a water-repellent layer.

However, all these procedures are made more expensive and more difficult the follow-up work has disadvantages.

In the production of ceiling elements, for example, makes use of A subsequent pecking of the surface is necessary for roll-on-roll lightweight building boards, Plastic films are particularly problematic as they can even with larger die) d only can be processed within a certain temperature range. In addition, there is the risk that the film bides wrinkles if the tension is not perfect, the Mark yourself in the concrete. The use of stiff plates of smaller thickness in any case causes the formation of joints; this usually becomes a follow-up treatment necessary.

The application of oils, waxes or solutions containing paraffin makes it difficult the subsequent finishing work, e.g. the application of a floor covering, there the adhesive effect of Kleborn is reduced by the oil-soaked concrete elements or is completely prevented. Therefore, chemical cleaning or

Mechanical removal of residues required.

The invention is based on the object of providing a separating layer for Manufacture of concrete elements, in particular he to develop the lift-slab process, which enables a perfect separation of the concrete elements and no residues leaves behind in subsequent work processes (painting, spatula, gluing or Cleaning) cause poor adhesion or chemical or mechanical Make cleaning of the concrete surfaces necessary. The separating layer is soli without special knowledge Applied to concrete elements with simple, inexpensive tools. can be.

According to the invention, a separating layer for the production of concrete elements, especially for the lift slab process, made by going for water repellent Film formation of a hardened concrete surface at the same time as an aqueous po lyacrilat or polyacrylic acid solution and an electrolyte solution, in particular an alkaline earth salt or alkaline earth hydroxide solution.

Applying the two solutions aanf di? bonded, worry.

creased smoothed concrete surface can help clay portable or bit mobile sprayers.

The polyacrylate or polyacrylic acid solution can by known methods, e.g. by polymerizing acrylic acid in aqueous neutral or solution containing alkali in the presence of potassium persulfate as initiator A 10% polymer solution is preferably used to produce the separating layer used. All water-soluble alkaline salts can be used to fill the polymer and used for film formation. 10% solutions are preferably used.

The invention is to be described in more detail below using an exemplary embodiment explained.

Example On a set, carefully smoothed concrete surface a 10% aqueous polyacrylic acid solution neutralized with sodium hydroxide solution and a 10% calcium chloride solution is applied to fill the polymer in such a way that that both solutions are sprayed onto the concrete surface at the same time with spray guns will.

The formation of a closed film is shown by its white coloration during the precipitation of the polymer on the concrete surface. After the Water and hardening of the film can begin the following work.

The resulting separating layer has the following properties: You is sufficiently resistant to mechanical stress in the following Work processes (laying the reinforcing steel, concreting and compacting the Concrete).

After hardening, the separating layer is insoluble in water and shows Sufficient lightfastness for the period between application and concreting on .

The use of this separating layer reduces costs and time for the subsequent expansion work and is therefore disgusting for a economic use of the lift-slab method.

Claims (2)

Patent claims: 1. Method of making a release liner for manufacturing of concrete elements, in particular for the lift-slab method, characterized in that, that for the water-repellent film formation a hardened concrete surface at the same time with an aqueous polyacrylate solution or polyacrylic acid solution and an electrolyte solution, in particular an alkaline earth salt or alkaline earth hydroxide solution is treated. 2. The method according to claim 1, characterized in that the application of the two solutions on the smoothed concrete surface with the help of portable or mobile jumping devices takes place.