JP2512988Y2 - A waterproof sheet that prevents the water-swelling clay from falling off in the dry state and allows passage in the gelled state - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a waterproof sheet used for waterproofing a structure in civil engineering and construction work.

More specifically, in a laminated waterproof sheet in which one side of a water-impermeable sheet such as polyethylene is coated with granular particles of water-swelling clay, the water-impermeable sheet is produced by utilizing the adhesive property of the clay or the clay itself. The granular particles of water-swellable clay that are adhered on one or both sides of the product easily fall off the surface of the impermeable sheet such as polyethylene, which makes it difficult for packaging, shipping work, and handling on site. To improve
A mesh that prevents the granular particles of water-swelling clay from falling off while it is in a dry state, and when it absorbs water and swells and gels, allows the generated gel to pass and flow to the outside. A laminated waterproof sheet having a size.

[Prior Art] As a waterproof sheet of this type, 1) as shown in FIGS. 2 (A) and 2 (B), a thickness of 0.3 to
A layer 2 of granular particles of water-swelling clay having a particle size of 5-150 Messi is deposited on one side of a water-impermeable sheet 3 of 1.5 mm polyethylene or the like, and edge portions 14, 15 and the like are formed as necessary. And is supplied as a long roll-shaped waterproof sheet having a length of 7 to 50 m, and the surface of the water-swelling clay is exposed on the side not covered with the sheet, 2) Typically, Japanese Patent Laid-Open No. 60-240446 (the third part attached to the present application)
As shown in FIGS. (A) and (B)), a highly water-absorbing and gelling substance 2 is sandwiched between two water-permeable material sheets 4 such as a non-woven fabric, and Gelling substance 2
By bonding and fixing the water-permeable material sheet 4 and the water-permeable material sheet 4 with a water-resistant adhesive agent 5, water-swelling clay, which is a highly water-absorbing and gelling substance, is sandwiched between the two water-permeable material sheets 4. There are two types: the type that is normally held in roll form and the type that is supplied in roll form.

These two types of waterproof sheets are related to the difference in their structures, and a remarkable difference is recognized in that they utilize the characteristics of a highly water-absorbing and gelling substance.

As is clear from the structure, the type 1) waterproof sheet has a layer of water-swelling clay, which is a highly water-absorbing and gelling substance, and one side of which is made of an impermeable sheet such as high-density polyethylene. Although it adheres to the surface, the other surface remains exposed and comes into direct contact with the soil or concrete surface, which is the object of construction, and the moisture that was previously present in the soil,
When it comes into contact with water leaking from construction objects such as ponds and dams, a boundary layer of gel of water-swelling clay, which is a gelling substance, is formed near the contact surface to form a strong waterproof layer.
Further, due to the volume expansion due to the swelling of the clay along with the gelation, the pressure at that portion also increases, competing with the waterproofing effect of the gel layer to achieve a strong waterproofing effect. Second
The prevention effect including the linear connection seam between the waterproof sheets will be described with reference to FIG.

The two waterproof sheets 1A and 1B are overlapped at both ends 1X and 1Y, and are joined by a collared nail 8.

In the figure, the upper tarpaulin 1A and the lower tarpaulin 1B, the bentonite layer 2W in the part away from the joint is the work piece 2S.
Although it is in direct contact with the soil, especially when the work is soil, the original soil 2S and the swollen and gelled waterproof sheet 2W are
Due to the volume expansion due to swelling, they mix with each other under pressure to form a dense and strong intermediate boundary layer to prevent water leakage.

In the figure, the side surface 2X of the upper waterproof sheet 1A that comes into contact with the soil, which is the work piece, and the side surface 2Y of the lower waterproof sheet 1B that is exposed to water or air have a waterproof layer 2Z made of swollen bentonite. Has been formed.

As can be understood from the above description, in the type 1) waterproof sheet, the granular water-swelling clay such as bentonite is directly contacted with the soil as the construction object without passing through the water permeable sheet or the like. It is possible to say that the increase in pressure and the increase in thickness due to the swelling are auxiliary actions for strengthening the boundary waterproof layer, with the main object being to form a dense and strong boundary waterproof layer.

On the other hand, the waterproof sheet of the type 2) is disclosed in JP-A-60-
No. 240446 [FIGS. 3 (A) and (B) attached to the present application] and the description of the detailed description of the invention in the specification, particularly the upper left column and the upper left column of the third leaf of the publication (total page 283). According to the water-stop effect test table in the pressurized state described in,
In the water-stop effect test, the obtained waterproof sheet is used as a permeable membrane, and the water-stop effect is the amount of water leakage for three items: the thickness of the waterproof sheet before water addition, the applied pressure, and the thickness of the waterproof sheet after water addition. It is clear from the point that it is examined in contrast with the above, its water-stopping effect depends on the increase of contact pressure due to the volume expansion of granular bentonite, which is a highly water-absorbing and gelling substance, so to speak This is due to the packing effect used in joints and chemical machinery.

Further, in the description, there is no mention at all on the permeability of the impermeable sheet to gel, the fact that the swollen and gelled bentonite or the like directly contacts the work to form a dense intermediate waterproof boundary layer. .

[Problems to be solved by the invention] When water-swelling bentonite or the like comes into contact with water and swells and gels, it comes into contact with soil, which is the work piece, and forms a dense and strong boundary waterproof layer, 1) It is widely used with the support of the user because the type of tarpaulin has some advantages, but for a few minutes granular particles of water-swelling clay
Due to the structure in which the surface of the impermeable sheet such as polyethylene is adhered to the surface with an adhesive, small particles of water-swelling clay drop off little by little during work and adhere to the hands and clothes of workers. However, there is a problem that the work site, especially indoor work, scatters on the floor and affects the work itself, and that it takes time to perform subsequent cleaning, and a solution has been demanded.

Measures were also taken to improve the adhesive strength by improving the adhesive and the adhesive method, but the granular particles themselves have the property that they easily fall off and scatter, so there is a limit to improvement by improving the adhesive strength. However, the fundamental solution was difficult.

[Means for Solving the Problems] On the surface of a water-impermeable sheet such as polyethylene, the upper surface of a layer of granular particles of water-swelling clay coated with an adhesive or the like is further covered with a porous sheet. Then, a granular small piece such as bentonite is sandwiched between the surface of the impermeable sheet and the inner surface of the porous sheet to prevent the granular piece from falling off.

On the other hand, by selecting the mesh size of the porous sheet to a range in which granular small pieces such as bentonite are prevented from passing, but not only water but also swollen and gelled bentonite and the like are allowed to pass. Solved the problem.

[Operation] Since the mesh size of the porous sheet is selected within the above range, while granular particles such as bentonite are in a dry state, they are prevented from falling through the mesh of the porous sheet. However, since water can pass through the water, the water passes through the mesh and enters the inside.As a result, gelated bentonite, etc., leaches outside through the mesh due to volume expansion and pressure increase due to swelling. A waterproof boundary layer is formed between the work and the work piece to provide a waterproof effect.

[Embodiment] FIGS. 1 (A) and 1 (B) show, as a basic embodiment of the present invention, waterproof treatment is applied to only one side and both sides of a water-impermeable sheet, respectively. It is a side view which shows a state.

Reference numeral 10 in the figure indicates the entire waterproof sheet, 11 is a water impermeable sheet of polyethylene, and the sheet itself is blackened by a pigment containing carbon black or the like.

Reference numeral 12 is a layer in which water-swellable clay is granulated and laminated and is a mixture of granular clay having a particle size of 4 to 0.1 mm and corresponding to 5 to 150 mesh as a whole. Reference numeral 13 is a porous sheet such as a woven fabric arranged on the surface of the granular clay layer 12 with an adhesive or the like.

These granular clays are adhered to the surfaces of the water-impermeable sheet 11 and the porous sheet 13 that face each other, but the adhesive is the surface of the water-impermeable sheet 11 and the porous sheet 13,
Further, it is difficult to illustrate because it is thinly removed by a spray method or the like so as to be as uniform as possible on the surface of each granular clay over each layer of the granular clay layer 12 forming several layers.

As already mentioned in the previous section, the conditions required for the porous sheet 13 are that the finest 0.1 mm particles in the clay granules constituting the granular clay layer 12 do not fall off, and this type of waterproofing Since it allows gelation of granular clay as a basic condition of the sheet, it has water permeability that allows water to pass freely, and further, gelled clay passes through and leaches out, so that soil etc. It must be able to pass through the clay gel to allow it to move towards the object.

In other words, it has not only the water permeability but also the mesh porosity of the mesh which is slightly coarse to the extent that it allows the passage of clay gel which is slightly more difficult to pass than water, and is the finest grain in the clay granules. It is required to be a porous sheet of mesh to the extent that particles with a diameter of 0.1 mm do not fall off.

As a sheet that meets these conditions, a particle size of 0.1 m
Although it is suitable if it is a porous sheet finer than 150 mesh corresponding to m (100μ), granular clay is originally fragile and is pulverized due to contact between clay particles and other objects, vibration, etc. Naturally, the proportion of fine powder finer than the grain size of 0.1 mm which is the control limit at the beginning of granulation or as a waterproof sheet is increased.

Since it is actually necessary to use a porous sheet finer than 150 mesh, it is necessary to examine to what extent the porous sheet is suitable for the passage of clay gel.

Therefore, as a finer item including 150 mesh, 5 kinds of 200, 330, 440, 500 mesh wire mesh, Tetoron sheet (a porous sheet used for screen printing) and wire mesh are dipped in water and clay gel swollen sufficiently The results of pouring and measuring the state of passage are shown below.

From the above results, although there is no problem in the passage of the clay gel with the porous sheet of 150 to 330 mesh, the passage becomes difficult with 440 mesh and it is necessary to apply pressure. However, it can pass under the condition that the ground pressure is applied. Clay gel does not pass through with 500 mesh, so it cannot be used for the porous sheet of the present invention.

Which of the 150-330 mesh porous sheets to use is a matter of how much the user will tolerate the loss of fine clay that is smaller than 0.1 mm in particle size.

[Effect of the device] A porous sheet within the range of 150 to 330 mesh is placed on the exposed surface of the granular clay adhered to the surface of the impermeable sheet such as polyethylene on the opposite side to the adhered side. Due to the relatively simple structure of deposition, it is possible to effectively prevent the granular clay sandwiched in the middle and the fine pulverized clay generated by crushing the granular clay from falling off and gelling. Since clay can pass through and leach out, move toward an object to be constructed such as soil to form a strong boundary waterproof layer tank, it greatly contributes to waterproof construction and waterproof sheet related industries.

[Brief description of drawings]

1 (A) and 1 (B) are side views showing an embodiment of the waterproof sheet of the present invention, and FIGS. 2 (A) and 2 (B) and FIGS. 3 (A) and 3 (B) are related arts. It is a schematic explanatory drawing which shows. Explanation of symbols 10 ,: Waterproof sheet, 11 ,: Water-impermeable sheet, 12 ,: Granular clay layer, 13: Porous sheet.

Claims (4)

(57) [Scope of utility model registration request] 1. A layer composed of granular particles of water-swelling clay is attached to at least one surface of a water-impermeable sheet such as polyethylene, and is used for civil engineering, bottom wall, side wall, floor of building structure, water conduit, etc. In a waterproof sheet used for waterproofing a place where water may leak, the waterproof sheet is further adhered to the surface of a layer composed of the granular small pieces of the water-swellable clay, and the impermeable sheet. And a porous sheet for holding the layer of the water-swellable clay between them, and the granular sheet passes through the porous sheet while the water-swellable clay is in a dry state and falls off to the outside. When the gel is formed by absorbing water and swelling and swelling, it has a mesh size enough to allow the generated gel to pass through and flow to the outside. Prevents falling and prevents passage in a gelled state Contents waterproof sheet. 2. The waterproof sheet according to claim 1, wherein the granular clay layer is an aggregate of small particles each having a particle size in the range of 5-150 mesh, and the porous sheet has a mesh size of 150. A waterproof sheet that prevents water-swelling clay from falling off in a dry state and allows passage in a gelled state, which is in the range of −440 mesh. 3. The waterproof sheet according to claim 1, wherein the porous sheet has a mesh size in the range of 150 to 330 mesh, and the water-swellable clay is removed in a dry state. A waterproof sheet that prevents the passage and allows passage in a gelled state. 4. The waterproof sheet according to any one of claims 1 to 3, wherein the granular clay layer and the porous sheet disposed on the upper surface of the granular clay layer are the water-impermeable sheet. A waterproof sheet that prevents water-swellable clay on both sides from falling off in a dry state and allows passage in a gelled state.