JPH0686761B2 - Mortar finishing method for architectural base materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a cement mortar after applying a shrinkage reducing agent for cement on a mixture layer composed of a lightweight aggregate and a hydraulic substance formed on a base material on a plate. The present invention relates to a mortar finishing method for an architectural base material, which is characterized by coating.

(Prior Art) Conventionally, in the mortar coating of wooden buildings, a mortar base material for construction has been devised in which a cement mortar coating layer is formed in advance on a wooden plate-like substrate, and this base material is labor-saving in the wet method. It is often used as a member.

Mortar finishing using this base material is a sufficient finishing method by omitting the lath base material plate-clad, felt-clad, lath wire mesh-clad and undercoat coating and applying a topcoat coating. It is what is done.

Further, if a cement mortar coating layer containing synthetic resin foamed particles is formed on a wooden plate-like substrate, the thickness of the cement mortar coating layer itself can be increased, and in terms of weight reduction, workability, etc. It is an excellent, almost dry type mortar finishing method.

(Problems to be solved by the invention) However, in the finishing method using such a base material, even after the base material is attached between the structural materials, the drying shrinkage of the cement mortar coating layer coated with time is reduced. Therefore, a warp occurs with the structural material as a fulcrum, which causes a new problem that cracks occur not only in the butt joint between the base materials but also along the structural material.

Furthermore, as a result of a coating boundary surface being formed between the cement mortar coating layer and the base material, an external impact force is likely to be concentrated on this boundary surface, and a separation phenomenon may occur at the boundary surface.

On the other hand, even if the above peeling phenomenon does not occur, there is an advantage that the total strength as the outer wall material increases because the finishing material is directly applied to the base material, but on the other hand, in terms of aging of the structural material itself. There was a weak point that the effect of preventing cracks could not be expected so much.

In order to solve such problems, it is possible to prevent warpage and bending by thickening the plate-shaped base material itself, by installing it horizontally between structural materials or by reducing the space between structural materials. Also, as the outer wall finishing material such as cement mortar coated on the base material, those having less drying shrinkage have been selected and used.

However, in both cases, labor and member costs are involved, but there is a problem in that the expected effect cannot be obtained.

(Means and Actions for Solving Problems) Therefore, the present invention provides a cement mortar after applying a shrinkage reducing agent for cement on a mixture layer composed of a lightweight aggregate and a hydraulic substance formed on a plate-shaped substrate. An attempt is made to provide a mortar finishing method for a building base material that solves the above problems by performing construction.

Hereinafter, the mortar finishing method of the architectural base material of the present invention will be described in detail.

First, as a building base material used in the present invention, a waterproof adhesive layer 2 is provided on the surface of a plate-shaped substrate 1 as shown in the figure, and a lightweight aggregate 31 and a hydraulic adhesive are provided on the upper surface of the waterproof adhesive layer 2. Substance 32
A mixture layer 3 consisting of is applied.

The plate-shaped substrate 1 is usually a plywood of about 4 to 12 mm, a hard board,
Wood-based substrates such as particle boards and inorganic plate materials are used.

The waterproof adhesive layer 2 is formed in order to prevent rainwater and surplus water for hardening mortar from entering from the outer surface and to improve the adhesiveness with mortar, and is usually used in a waterproof coating method. Resins with high adhesive properties, such as acrylic styrene, synthetic resin such as ethylene vinyl acetate, butyl rubber, SB
Synthetic rubber resins such as R and MBR are used.

The waterproof adhesive layer 2 is formed to have a desired thickness by a coating device such as a roll coater.

Further, as the lightweight aggregate 31, fine aggregate such as synthetic resin foam granules or pearlite is used. After the lightweight aggregate 31 is kneaded with a hydraulic substance 32 such as cement and water, the plate-like substrate 1 A desired thickness is formed on the surface by a roll coater or the like.

The method for manufacturing the above-mentioned architectural base material is specifically disclosed in Japanese Patent Application No. 53-102729 (Japanese Patent Application Laid-Open No. 55-30049), which the applicant has already applied for.

On the other hand, the shrinkage-reducing agent 4 used has the function of lowering the surface tension inside the mortar during mortar drying shrinkage, and is usually one or a mixture of two or more compounds represented by the general formula of RO (AO) nH. Consists of.

In the above formula, R is an alkyl group having 1 to 4 carbon atoms, A is one or two alkylene groups having 2 to 3 carbon atoms, and n is 1 to 1.
It is a sum of 10, and polyoxyethylene alkylphenol ether and lower alcohol alkylene oxide adducts are preferable.

The coating thickness of the shrinkage-reducing agent 4 on the mixture layer 3 composed of cement and synthetic resin foam particles formed on the plate-shaped substrate 1 is usually 200 to 500 g /, although it depends on the thickness of the mixture layer 3.
It is applied in the range of m2.

At the time of coating, a commonly used coating device and means such as brush coating, air spray coating and roll coater coating can be used.

If the coating thickness is less than the above range, the effect of reducing the shrinkage of the cement mortar 5 is not sufficient, and if it is more than the above range, the adhesiveness between the mixture layer 3 and the cement mortar 5 is poor, and the plastering finish. Problems such as poor workability and peeling of cement mortar 5 occur.

(Effects of the Invention) As described above, the mortar finishing method for a building base material of the present invention is a simple method of applying a shrinkage reducing agent before coating a cement mortar, and the plastering workability is also good,
Moreover, it is a mortar finishing method for a construction base material that is extremely effective in terms of both technology and economy, such as a high effect of preventing mortar from cracking.

(Example) Next, an example of the present invention will be described.

Example 1 3 parts of expanded polystyrene particles and 100 parts of Portland cement were placed on plywood having a thickness of 6 mm which had been subjected to antiseptic / insecticide treatment.
Part of water and 20 parts of water is formed into a thickness of about 6 mm by a roll coater and dried, then 300 g / m2 of ethylene oxide adduct of lower alcohol "Trade name: Tetra Guard S3 (manufactured by Nippon Cement Co., Ltd.)" is applied and dried. It was

Next, when a 12 mm iron coating of an exterior cement mortar having a normal mixture (Portland cement 1: sand 3) was applied, an exterior finish with good coatability and almost no cracks was obtained.

[Brief description of drawings]

The figure is a schematic cross-sectional view showing a state in which cement mortar is applied to a building base material. 1 ... plate-like substrate, 2 ... waterproof adhesive layer, 3 ... mixture layer, 31 ... lightweight aggregate, 32 ... hydraulic material, 4 ... shrinkage reducing agent for cement, 5 ... cement mortar.

Claims (1)

[Claims] 1. A cement composed of a mixture of one or more compounds represented by the general formula RO (AO) nH on a mixture layer composed of a lightweight aggregate and a hydraulic substance formed on a plate-shaped substrate. A mortar finishing method for a building base material, which comprises applying a cement mortar coating after applying a shrinkage reducing agent.