SU852840A1 - Method of freshly layed concrete maintenance - Google Patents

Description

(54) METHOD OF CARE FOR FRESHLY DESIGNED

12

The invention relates to the field of building materials, in particular, to methods that are pre-specified for the moisture-free maintenance of freshly laid monolithic concrete, which hardens under conditions of a dry hot climate.

A known method of caring for fresh-laid concrete by applying a 507 ° aqueous emulsion on its surface based on polyvinyl chloride 1.

The closest to the invention in its technical essence and the achieved result is the method of care for fresh concrete, by applying to the 15 surface of the concrete a 0.007-0.014% aqueous solution of high molecular weight cetyl alcohol 2.

The known method of care for fresh concrete does not sufficiently prevent the evaporation of moisture from the surface of the concrete. Concrete treated in a known manner, has insufficient strength, frost resistance, water resistance. 25

The purpose of the invention is to reduce moisture loss, increase strength, frost resistance and water resistance.

This is achieved by the fact that in the method of care for freshly laid concrete by way of 30 CONCRETE

carrying a film-forming substance onto its surface, a 5-10% aqueous solution of polyvinyl alcohol is applied to the surface of the concrete.

The preparation technology and method for applying the depressor is the following; polyvinyl alcohol (grade PVA 16/1 or PVA 20/1) is dissolved with water at room temperature, the resulting 5-10% aqueous solution of polyvinyl alloy is applied to the surface of freshly laid concrete with a fishing rod. After the first layer dries, a second layer of 5-10% polyvinyl alcohol solution is applied. Examples of performance and physical and mechanical indicators of the proposed method and prototype are given in the table.

The proposed method of caring for fresh concrete has been given to protect the concrete from evaporation of moisture from it, and has a high degree of water resistance during the month. Significantly reducing the loss of moisture from concrete, and the proposed method allows to obtain increased strength (up to 25%) and durability (MRS 200, B-6) of concrete hardening under conditions of high temperatures and low humidity.

A moisture-based depressor based on polyvinyl alcohol is fairly stable, ensuring uniform distribution over the surface of the concrete, it is non-toxic; does not contain components that react with cement and inhibit the hardening of concrete, thus excluding the possibility of destruction of the surface layer of concrete.

After drying, the film-forming coating based on polyvinyl alcohol acquires a silver-gray color, improving the decorative appearance of concrete.

The economic effect of using a PVA-based moisture evaporation depressant is due to the increased durability of the concrete, the simplification of the preparation technology, the reduction of safety costs, and O-91 rubles. on 1 m of the laid concrete.

Claims (2)

Invention Formula A method of caring for fresh concrete by applying a film-forming substance to its surface, characterized in that, in order to reduce moisture loss, increase the strength, frost resistance and water resistance of concrete, 5-10% aqueous solution of polyvinyl alcohol is applied to the surface of the latter. Sources of information taken into account in the examination; 1. Skupin L. Polymer solutions and plastic concrete. SI., M., 1967, p. 126. 2. USSR author's certificate No. 652154, C 04 B 41/30, 02.08.77 (prototype) ..,. i