JPH01287367A - Formwork for concrete of improved durability - 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 "Field of Industrial Application" The present invention relates to a formwork that improves the durability of concrete cast within the formwork.

"Prior Art" Conventionally, as shown in Figures 6 to 8, this type of formwork for forming durable concrete has been designed to improve the shape and dimensions of structures to be constructed, such as columns, beams, walls, floors, etc. A weir board 1 made of plywood or the like is assembled into a predetermined shape in accordance with the above, and a large number of small holes 2 for dewatering are bored over the entire surface of the weir board 1, and a bar 4 and a thick end are installed on the outside of the weir board 1 to hold it. Formworks having a structure in which timber or supporting frames 3 are arranged are known.

Concrete is poured into this formwork in the same way as in normal formwork, and moisture in the concrete near the weir plate l of this formwork is discharged to the outside of the formwork through the small holes 2. Then, the concrete near the weir plate l is dehydrated and a dense concrete layer is formed.

Therefore, the existence of this dense concrete layer makes it possible to slow down the carbonation speed of the concrete placed in the formwork and improve the durability of the concrete.

``Problems to be Solved by the Invention'' However, such conventional formwork for forming concrete with increased durability is often unsatisfactory when used.

That is, the weir plate is required to have such strength that deformation such as deflection is not noticeable due to the pressure of concrete when it is placed inside the formwork.

However, since the weir plate 1 of the above-mentioned conventional durability-enhancing formwork has a large number of small holes 2 drilled over its entire surface, a cross-sectional defect occurs, and the weir plate 1 with no small holes 2 is It is undeniable that the strength will be lower than that of a plate. In particular, when the small hole 2 is expanded and the cross-sectional area is increased for the purpose of improving durability, this decrease in strength may become significant.

In addition, as shown in Fig. 8, when the shoring frame 3 is provided on the outer surface of the weir plate l via the struts 4, the strength of the weir plate l decreases as described above, and when concrete is poured. Then, the weir plate 1 is deformed outwardly between the above-mentioned beams 4.

Therefore, the surface of the poured concrete does not become flat and it is difficult to expect an improvement in the finishing accuracy. Furthermore, narrowing the distance between the trusses 4 in order to prevent this bending deformation results in an increase in the material for the trusses 4, and therefore an increase in the weight of the entire formwork. Even so, if the number of small holes 2 is reduced, water will not flow out sufficiently, and therefore durability cannot be expected to improve. Furthermore, in this formwork, small holes 2 are drilled in the entire surface of the weir plate I that is in contact with the poured concrete.
Since moisture in the concrete leaks out from the mold, when the formwork is removed, the surface of the formed concrete is not smooth and the mortar protrudes from the small holes, resulting in an unsightly appearance.

The present invention has been made in view of the above-mentioned circumstances, and in a formwork for forming concrete that improves the durability of poured concrete by dewatering it, the strength of the weir plate can be reduced without sacrificing the durability improvement effect. □The purpose is to provide a formwork for forming concrete with improved durability that can prevent the above problems and improve the finishing accuracy and appearance of the poured concrete surface.

"Means for Solving the Problems" In order to achieve the above object, the durability-enhancing concrete forming formwork according to the present invention includes a weir plate and a frame material for reinforcing the weir plate. A plurality of narrow grooves extending in the short side direction are provided on the surface of the weir plate, and a water-permeable sheet is pasted on the inner surface of the weir plate except for the inner surface of the narrow groove.

In addition, as a preferable implementation means of the durability-enhancing concrete molding form of the present invention, the above-mentioned narrow grooves are provided on the surface of the weir plate in a state that they intersect with each other.

"Function" In the formwork for concrete forming configured as above,
The water and mortar paste contained in the concrete near the weir plate flow toward the water-permeable sheet, and only the water passes through the sheet and reaches the narrow grooves on the weir plate surface. Since this narrow groove is provided extending in the direction of the short side of the weir plate, the moisture that reaches the narrow groove will travel along the narrow groove through the shortest distance, and the water will be transferred to the narrow groove located below. is discharged outward from either end.

At the same time, moisture contained in the concrete inside the formwork and mortar paste also move toward this weir plate. At this time, the aggregate located near the weir plate acts as a filter and causes clogging, resulting in the formation of a dense concrete layer near the weir plate.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a perspective view showing the structure of the formwork of this embodiment. The code lO in the figure is a formwork, and this formwork 10 is connected to the weir plate 11.
and a thick end member 12 for supporting the weir plate 11 from the outside and fixing it in a predetermined position. The above weir plate 11
Plywood or metal plates are used for this purpose. This weir plate 11
As shown in Figures 1 and 2, there is a weir plate 1 on the surface of the
A plurality of narrow grooves 13 are provided extending in the direction of the short side.

When the weir plates 11 are assembled into a predetermined shape and size as shown in FIG. 1, the weir plates 11 located on both sides
The narrow groove 13 is formed in the form of a vertical groove from the upper end to the lower end of the weir plate 11 and is located on the inner surface side of the formwork 10.

Further, reference numeral 14 is a water-permeable sheet pasted on the surface of the weir plate 11, as shown in FIG. sheet 14
Plastics, textiles, hard paper, etc. are used as the water-permeable materials that make up the material.

Next, the effects of concrete forming according to this embodiment will be explained.

Figure 4 shows the state in which the weir plate 11 configured as described above is fixed, a water-permeable sheet 14 is pasted on the surface of the weir plate 11 to form the formwork 10, and concrete C is poured inside the formwork. To explain based on this, among the concrete C placed in this formwork 10, the concrete CI near the weir plate 11
Moisture and mortar paste contained in the weir plate 11 move toward the water-permeable sheet 14 attached to the weir plate 11, and only the water permeates the water-permeable sheet 14 and flows into the narrow grooves 13 of the weir plate 11. The water that has permeated and flowed into the narrow grooves 13 of the weir plate 11 passes through the narrow grooves 13 to reach the lower part of the weir plate 1-1, and is drained to the outside of the formwork 10.

At the same time, moisture and mortar paste contained in the concrete C2 located outside the concrete Ct also move toward the outside of the formwork 10 (toward the weir plate 11 side). At that time, since the aggregate near the weir plate 11 acts as a filter,
The mortar paste becomes clogged near the sheet 14 of the weir plate IK, forming a dense concrete layer C3. By forming this concrete layer C3 along the inner surface of the weir plate 11, the carbonation speed of the concrete C placed in the formwork 10 can be slowed down. That is, this concrete layer C3 improves the durability of concrete C. Furthermore, since the air on the concrete surface in contact with the weir plate 11 easily escapes outside the formwork IO, air bubbles are less likely to form on the concrete surface.

As described above, concrete with improved durability is poured and formed. Here, weir plate 1 according to this embodiment
1 is provided with the thin grooves 13 for dewatering, as mentioned above, so there is no loss of cross section as in the conventional case where a large number of small holes are temporarily bored in a bottle, so the strength of the weir plate 11 is reduced. There is almost no decline.

In addition, the groove I3 provided on the surface of the weir plate 11 is narrow, and the water-permeable sheet 14 is stuck on the surface of the weir plate 11, so even after pouring concrete C, the surface finish of the member remains accurate even after demolding. has almost no effect. The appearance of the concrete surface is also good.

Moreover, the physical properties of the concrete are improved, such as increasing the compressive strength and abrasion resistance of the concrete, as well as increasing the specific gravity, and the durability of the structure can be improved, which is exactly the same effect as in the conventional example. be.

FIG. 5 shows another embodiment of the weir plate 11. In other words, weir plate 1
One narrow groove 13 is provided in a diagonally intersecting state.

The use of the water-permeable sheet 14 attached to the surface of the weir plate 11 is the same as described above.

Therefore, this weir board 1! By using this, it is possible to obtain the same functions and effects as those of the above embodiment. In particular, since the weir plate 11 of this embodiment is provided with narrow grooves 13 diagonally intersecting, water in the concrete mentioned above flows in two directions, and the weir plate 11 The advantage is that concrete can be reliably dewatered regardless of the installation situation.

It goes without saying that the shape of the narrow groove of the weir plate and the cross-sectional shape of the narrow groove are not limited to those of the above embodiment as long as they achieve the object of the present invention.

"Effects of the Invention" As explained above, the formwork of the present invention has a structure in which a plurality of thin grooves for dewatering are provided on the surface of the weir plate, and the weir plate itself has no cross-sectional defects, so compared to the conventional one. This prevents the strength of the weir plate from decreasing. This prevents the weir plate from deflecting outward as concrete is placed, and improves finishing accuracy.

In addition, the grooves provided on the surface of the weir plate are narrow, and a water-permeable sheet is pasted on the surface of the weir plate, so concrete does not protrude outward from these narrow grooves, and the concrete The appearance of the surface is also improved. Moreover, water near the substrate is reliably discharged to the outside of the formwork through the sheet and narrow grooves, which forms a dense concrete layer on the concrete surface, improving the durability of the concrete as before. You can also do it.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention.
The figure is a perspective view for explaining the structure of the formwork of the present invention.
The figure is an enlarged perspective view of the weir plate, Figure 3 is a partially cutaway perspective view of the weir plate and sheet, Figure 4 is a partially cutaway cross-sectional view of the weir plate with concrete poured into the formwork, and Figure 5 is a partially cutaway perspective view of the weir plate. A perspective view showing another embodiment of the weir plate, and FIGS. 6 to 8 are partially cutaway perspective views and enlarged front views of essential parts showing the respective structures of conventional weir plates. lO... Formwork! ! ...Weir board, 12.
...Frame material, 13...Narrow groove, 14...
...Sheet.

Claims (2)

[Claims] (1) A formwork comprising a weir plate and a frame material for reinforcing the weir plate,
A plurality of narrow grooves extending in the short side direction of the weir plate are provided on the surface of the weir plate, and a water-permeable sheet is pasted on the inner surface of the weir plate other than the inner surface of the narrow groove. Formwork for concrete molding with improved durability. (2) The formwork for forming concrete with improved durability according to claim 1, wherein the narrow grooves are provided in a diagonally intersecting state on the surface of the weir plate. .