JPS62111061A - Prevention of crack of outer wall - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The base is not integral throughout, but is divided into several blocks. The present invention relates to a construction method capable of preventing cracks in an outer wall when the outer wall is constructed by coating mortar on the surfaces of foundations that are butted against each other.

(Prior art) When plywood or concrete blocks are butted together to create a wide base and mortar is painted on the surface, cracks will occur in the mortar due to the expansion and contraction of the base, regardless of whether lath is applied to the base surface or not. This has often been considered a problem. There are various possible causes for this, but when a large shear stress that cannot be absorbed by the mortar is applied between the base surface and the mortar, cracks occur from the base side of the mortar and cracks appear on the outer surface of the mortar. It is thought that this is due to the fact that it is being propagated.

In order to prevent this, various attempts have been made to incorporate fibers into the mortar, but this method is not considered desirable due to the difficulty in uniformly mixing the fibers into one mortar, the complexity, and poor painting workability.

(Problem to be solved by the invention) When painting with mortar, it is important to prevent mortar cracks from occurring at least on the painted surface even if the base moves or one dimension changes. This is important from the perspective of preventing infiltration.

(Means for Solving the Problem) As a result of intensive research into preventing cracks on mortar-coated surfaces, the inventor found that the problem can be solved by making a network exist in a special form in the mortar layer. The present invention has now been completed.

That is, the gist of the present invention is that when applying mortar to a base surface having an abutting portion to form an outer wall, the mortar is applied in at least upper and lower layers, and between the upper and lower layers and at least at the abutting portion. This is a method of preventing cracks on the exterior wall by placing a net on the outside.

Hereinafter, the content of the present invention will be explained using the drawings.

1 to 3 show cross-sectional views of three examples of mortar-coated outer walls obtained by the construction method according to the present invention.

FIG. 4 is a sectional view showing an opening in the abutting portion of the base material of the painted outer wall shown in FIG. 1 and a crack state in the wall.

FIG. 5 shows a cross-sectional view of a painted wall obtained by a conventional construction method, and corresponds to a comparative example corresponding to FIG. 1 showing an example according to the present invention.

FIG. 6 is a sectional view showing openings and cracks in the abutting portions of the base material of the painted outer wall shown in FIG. 5.

In the conventional construction method, as shown in Fig. 5, the plywood IA, IA, .
The base is formed by being spread in...
A metal lath 6 is stretched and fixed on the surface,
Mortar (for example, mortar whose main solid components are Portland cement and sand is most widely used) is applied over it.

In this case, the lath 6 is for improving the bonding between the mortar and the base.

Although the explanation has been omitted because it is not particularly related to the structure of the present invention, when plywood is used as the base material for the wire, asphalt paper, etc. Waterproof paper is often placed between the plywood and lath.

Now, in the case of plywood and concrete, environmental conditions (
It is well known that the butt part 2 expands and contracts depending on moisture, temperature), but especially when it contracts, the butt part 2 opens with the lath 6, which applies tensile stress to the mortar layer 8, causing cracks 7.
B (Figure 6).

That is, in conventional construction methods, dimensional changes in the base often immediately lead to cracks throughout the entire thickness of the mortar layer 8.

In this case, lath 6 does nothing to prevent this crack from occurring. I can't get up.

The present invention solves this problem, and as shown in FIG. 1, the base materials IA, LA, . ...... to form a base, cover the surface widely with lath 6, and then apply mortar lower layer 3.
After applying and setting, or before that, align the mesh piece 5A to the same position as the abutting parts 2, 2, old...
Then, a mortar upper layer 4 is applied from above.

In this case, the net-like body must be made of metal, synthetic AM, #alkaline ceramic TA fiber, carbon fiber, etc. that has corrosion resistance for many years in one mortar.In this case, the thickness of the fiber, thread, wire, etc. .

The weaving method is not particularly limited, but the mesh needs to be large enough to allow the upper and lower layers of mortar to pass through and connect to each other, and is preferably about 1 to 10 m.

FIG. 2, which is another embodiment of the present invention, shows that a concrete base material IB is laid across the butt portions 2 to form a base, a mortar lower layer 3 is applied to the surface of the base, and a mortar lower layer 3 is applied on the surface of the base.
This shows a case where the butt portions 2.2, . things are used.

FIG. 3 shows another example of the base material IA shown in FIG.
On the layer consisting of the lath 6 and the mortar lower layer 3 in this order, there are several abutting portions 2.2, . . . . At the same time, the net-like body 5C having a width that covers the butting portion 2.2, . . .
The mortar is then spread to cover the upper part of the mortar, and the following mortar crack prevention effect occurs from the mortar. The effect will be explained with reference to FIGS. 1 and 4.

If the base material IA in FIG. 1 is displaced or deformed due to shrinkage or the like and separation occurs at the abutting portion 2.2, the effect extends to the mortar lower layer 3 and causes cracks 7A. However, this crack collides with the mesh body 5A and stops. That is, the propagation of cracks can be easily prevented by inserting a mesh into the mortar layer. This propagation prevention effect is the second
The same results can be obtained in both the case shown in the figure and the case shown in FIG.

By employing the above configuration, the present invention can obtain the effects shown in the overall description and the description of the embodiments.

[Brief explanation of drawings]

Figures 1, 2, and 3 are cross-sectional views of a mortar-coated wall obtained using the construction method of the present invention, and Figure 4 shows the opening of the butt part of the base material of the painted wall shown in Figure 1 and the wall. Each shows a cross-sectional view in a cracked state. FIG. 5 is a sectional view of a painted wall obtained by the conventional construction method, and FIG. 6 is a sectional view of openings and cracks in the abutted portion of the base material of the painted wall shown in FIG. 5. The symbols used in the drawings will be explained.

Claims (2)

[Claims] (1) When applying mortar to a base surface having abutting portions to form an outer wall, the mortar is applied in at least upper and lower layers, and a net-like structure is formed between the upper and lower layers and at least outside the abutting portions. A construction method for preventing cracks on exterior walls, which is characterized by placing. (2) The method for preventing cracks in an exterior wall according to claim 1, wherein the outer surface of the base surface having the abutted portion is lathed and mortar is applied to the surface.