JP3068445B2 - Lining sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lining sheet for preventing corrosion of concrete surface due to hydrogen sulfide or the like.

[0002]

2. Description of the Related Art In a concrete structure such as a sewage treatment facility, there is a problem that the concrete surface is corroded by an acidic gas such as hydrogen sulfide generated in the vicinity, and furthermore, a crack is generated to cause unnecessary leakage of wastewater. is there.

Conventionally, in order to prevent such problems caused by corrosion and cracks on the concrete surface, a large number of projections having a neck portion and a bulging portion at the tip thereof are formed on a synthetic resin sheet in a grid-like or staggered manner. A method has been proposed in which a plastic sheet for lining integrally provided in a shape is covered and fixed on concrete at the time of casting concrete (Japanese Patent Laid-Open No. 6-126837). The plastic sheet for lining used in this method is used for corrosion of concrete surface,
It is an excellent means for preventing the above-mentioned problems due to cracks.

However, according to the above-mentioned conventional lining plastic sheet, the lining plastic sheet undergoes thermal expansion and contraction due to heat generated during hardening of the concrete and changes in the environmental temperature after hardening, and partially peels off from the concrete surface due to elongation. There is a disadvantage that floating occurs.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a synthetic resin lining sheet which does not have the above-mentioned drawbacks.

[0006]

According to the present invention, in order to achieve the above object, a large number of mushroom-like projections comprising a body and an umbrella at the tip thereof are arranged in a grid pattern on the surface of a synthetic resin sheet. Or in a staggered and integrally formed lining sheet, the woven or non-woven porous fiber body is in a non-buried state at a flat surface portion of the synthetic resin sheet, and at a protrusion portion at the protrusion portion. The gist is a lining sheet that is buried at the base end and stretched over the surface of the synthetic resin sheet.

The porous fibrous body stretched over the lining sheet of the present invention is formed on the surface of the synthetic resin sheet in a non-buried state at a flat surface portion and a buried state at a base end portion of the protrusion at a protruding portion. , Which are stretched integrally and serve to suppress the elongation of the lining sheet due to the thermal expansion and contraction of the synthetic resin.

Further, the porous fibrous body stretched over the lining sheet is used to fix the lining sheet to the concrete surface between the concrete to be cast and the flat surface of the lining sheet. It serves as an escape path for air bubbles that may be generated, and improves the adhesion of the lining sheet to the concrete surface.

[0009] Needless to say, a large number of projections provided on the surface of the lining sheet are embedded in the concrete into which they are cast, and by their anchoring action,
This is for firmly fixing the lining sheet to the concrete surface.

As a method for integrally forming a large number of projections on the surface of a synthetic resin sheet as a lining sheet,
Usually, a roll forming method is applied.

The roll forming method employs a forming device comprising a mold roll having a large number of conical concave portions for forming projections formed in a checkerboard or zigzag pattern on a roll peripheral surface and a pressure roll facing the roll. A first step of pressing the molten material sheet supplied to the substrate to form a large number of conical projections on the material sheet, and heating the large number of conical projections on the material sheet obtained in the first step from the top And crushing the upper portion to form a mushroom-shaped projection having an overhanging umbrella.

According to the present invention, in the first step of the roll forming method, when a material sheet is supplied between a mold roll and a pressure roll, a porous fiber body is interposed between the material sheet and the mold roll. Let it. Then, at a position corresponding to the conical recess of the mold roll, the molten resin flows through the porous fibrous body and fills the conical recess while flowing toward the conical recess. In the flat part excluding the conical recess, the flat part except the conical recess is pressed against the flat part of the mold roll by the molten resin, so that it is half-buried in the molten resin and is in a non-buried state that is in close contact with the material sheet surface. It is stretched integrally. In the second step, the material sheet thus obtained is heated from the top with a hot plate or the like, and the upper part is crushed to a desired height in a softened state. By forming the mushroom-shaped projections with the parts, the lining sheet can be finished.

The projections of the lining sheet do not impede the flow of the concrete at the time of placing the concrete, exert an anchoring action on the concrete to be coated and fixed, and have a size and shape as long as they can be firmly fixed. Is not limited, but usually has a height of 3 to 10 mm and a diameter of 2 at the base end.
It is preferable that the umbrella part has a circular cross section within the range of 1.2 to 1.7 times the body part diameter.

The arrangement of the projections is basically a grid or staggered arrangement, but does not impede the flow of the concrete at the time of placing the concrete and exerts an anchoring action on the concrete to be fixed. The arrangement shape and the interval are not limited at all as long as they can be firmly fixed.

As the synthetic resin used for the synthetic resin sheet of the present invention, for example, a thermoplastic synthetic resin such as polyethylene, polypropylene, polyvinyl chloride and ethylene vinyl acetate is applied.

Further, the porous fibrous body used in the present invention is alkali-resistant, has high tensile strength, and is easily formed so that the molten resin is sufficiently filled into the conical concave portion of the mold roll when the projections are formed. Anything can be applied as long as it can pass through it. For example, a woven or nonwoven fabric made of synthetic fibers such as polyester fibers or inorganic fibers such as glass fibers is preferably used. Among them, a glass fiber net having 3 to 20 mesh squares, rhombuses and other desired meshes can be mentioned as the most suitable porous fibrous body.

As described above, in the lining sheet of the present invention, the porous fibrous material is formed on the surface of the synthetic resin sheet on which a large number of mushroom-shaped protrusions are integrally formed, in a non-buried state at a flat portion, The base end of the projection is buried and integrally stretched with a synthetic resin. And
The lining sheet suppresses elongation of the lining sheet due to thermal expansion and contraction of the synthetic resin due to the stretched porous fibrous body, and is generated between the concrete to be cast and the flat portion of the lining sheet. It functions as an escape path for air bubbles, and exhibits functions such as improving the adhesion between the lining sheet and the concrete by being interposed between the lining sheet and the concrete.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 (a) and 1 (b), the lining sheet (1) is composed of a body (3a) and an umbrella (1) on the surface of a synthetic resin sheet (2) made of polyethylene. 3b), a large number of mushroom-shaped projections (3) are arranged in a grid pattern, and a porous fiber body (4) made of a glass fiber net is formed of a synthetic resin sheet (2). The flat portion (2a) is in a non-buried state, and the base end (3c) of the projection (3) is in a buried state and is integrally stretched on the surface of the synthetic resin sheet (2). .

The dimensions of each part of the lining sheet (1) will be described.
The average thickness of a) is, for example, 1.5 mm including the porous fibrous body (4), and the cross section of all portions of the projection (3) is circular, and the base end (3c) 3 mm in diameter and 2.5 m in diameter at the upper end (3d) of the trunk (3a)
m, the diameter of the umbrella portion (3b) is 4 mm and its thickness (d) is 1
mm, and the overall height (h) was 5 mm.

The projections (3) were arranged in a grid pattern with a grid spacing (s) of 15 mm.

As the porous fiber body (4), a glass fiber net composed of a plurality of twisted yarns having a square of 15 mesh was employed.

Here, as an example of the method for manufacturing the lining sheet of the present invention, first, as shown in FIG. 2A, a forming apparatus (11) using a roll forming method is used. In step E), the synthetic resin (R) is heated and melted, extruded into a plate, and supplied between the mold roll (12) and the pressure roll (13), and simultaneously synthesized with the mold roll (12). A continuous porous fibrous body (4) is interposed between the resin (R) and pressed by both rolls to form a conical projection (3 ') on the surface, and the porous fibrous body ( 4) Obtain a material sheet (2 ') on which is stretched.

In this case, the part of the synthetic resin (R) flowing toward the conical recess (12a) of the mold roll (12) passes through the perforated portion of the perforated fibrous body (4) and is conical. Recess (12
In the other portion, the porous fibrous body (4) is pressed against the flat portion (12b) of the mold roll (12) and the synthetic resin (R) is brought into close contact with its own surface. As a result, the porous fibrous body (4) is buried in the synthetic resin (R) at a portion corresponding to the conical recess (12a), and is not buried in the surface of the synthetic resin (R) at other portions. A material sheet (2 ') having a large number of conical protrusions (3') stretched in this manner is obtained.

Next, as shown in FIG. 2 (b), a large number of conical projections (3 ′) on the material sheet (2 ′) obtained above.
While heating and softening the area near the top with a hot plate (14)
The desired height is crushed and then cooled to form an umbrella (3b). Thus, finally, the lining sheet of the present invention is obtained.

As shown in FIG. 3, the backing of the lining sheet (1) is bonded to the surface of the concrete formwork (21a) by fixing the covering of the lining sheet (1) obtained above to the concrete surface. After attaching the other concrete formwork (21b) correspondingly via the adhesive or the double-sided adhesive tape (22), concrete between the lining sheet (1) and the concrete formwork (21b) in the direction of the arrow. Is carried out.

[0027] Lining sheet according to the present invention (1)
When the lining sheet (1) is coated on the concrete surface, the lining sheet (1) does not peel off or float from the concrete surface due to thermal expansion and contraction.

[0028]

As described above, the lining sheet of the present invention has a woven or non-woven porous fiber on the surface of a synthetic resin sheet and a non-buried state on a flat surface of the synthetic resin sheet. In the protruding portion, the protruding portion is buried at the base end of the protruding portion, and a large number of mushroom-shaped protruding portions are arranged in a grid or staggered shape and are integrally formed. Can be used to cover concrete structures during construction of sewage treatment facilities, etc. to prevent corrosion of concrete surfaces and leakage of wastewater due to cracks. The thermal expansion and contraction of the lining sheet caused by the heat generation at the time and the change in the environmental temperature after curing is suppressed, especially the elongation is reduced, and the lining sheet is partially There is an effect that or peeling, the lifting of occurring can be prevented.

Further, when fixing the lining sheet on the concrete, the porous fibrous body stretched on the lining sheet is used between the concrete to be cast and the flat surface of the lining sheet. Since it is a escape path for generated bubbles, the generation of bubbles is reduced, the adhesion of the lining sheet to the concrete surface is further improved, and the anchoring action by many projections can be more effectively exerted. Thus, there is an effect that the lining sheet can be more firmly covered and fixed to the concrete surface.

[Brief description of the drawings]

FIG. 1 shows a lining sheet of the present invention, and FIG.
1A is a plan view, and FIG. 1B is a sectional view taken along line II.

FIG. 2 is an explanatory view of a process for manufacturing a lining sheet of the present invention, wherein FIG.
FIG. 2 (b) shows a step of forming a mushroom-shaped projection.

FIG. 3 shows a state where the lining sheet of the present invention is covered and fixed on a concrete surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lining sheet 2 ... Synthetic resin sheet 2a ... Flat part 3 ... Protrusion 3a ... Trunk part 3b ... Umbrella part 3c ... Base end part 3d ... Top end part 4 ... Porous fiber body

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E03F 11/00 B29C 63/26 E04G 9/10 103

Claims (1)

(57) [Claims] 1. A lining sheet in which a large number of mushroom-shaped projections comprising a body and an umbrella at the tip thereof are arranged in a checkerboard or staggered pattern on a surface of a synthetic resin sheet and are integrally formed. The woven or non-woven porous fiber body is in a non-buried state at the flat surface of the synthetic resin sheet,
A lining sheet in which the protruding portion is buried at the base end of the protruding portion and stretched on the surface of the synthetic resin sheet.