JPH07266482A - Structure of composite waterproof sheet - Google Patents

Abstract

PURPOSE:To obtain a structure of a waterproof sheet to be used for a large- sized water-barrier work which can cope with large movement of a base ground of the waterproof sheet to be caused by earthquake or other cause. CONSTITUTION:In a structure of a single layer composite waterproof sheet, a composite interface of a low elastic modulus material sheet 1 and a high elastic modulus material sheet 2 has both of an inadhesive area 4 and an adhesive area having a discontinuous or continuous non-drying pressure sensitive adhesive 3. Conductivity is improved to the continuous non-drying pressure sensitive adhesive 3 so as be used for a sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof sheet structure for a water shield work such as a reservoir and a final landfill disposal site, and prevents damage and leakage of the waterproof sheet against an earthquake or ground movement having uncertainties. Used to do. In particular, when it is difficult to repair the leakage of waste liquid due to damage to the waterproof sheet after the start of use, as in the case of water-filling works at a landfill site, ensure a wide range of safety measures to prevent leakage of hazardous waste liquid to the ground foundation. It has a great effect on the utilization of soil, helps prevent the penetration of harmful waste liquid into the ground, and has a great effect on the prevention of environmental pollution of harmful waste liquid.

[0002]

2. Description of the Related Art Conventional waterproof sheets used for waterproofing in civil engineering have been single-layer sheets made of the same material or composite sheets made of different materials. Due to its limited characteristics, the performance of the ground foundation is limited, and composite sheets of different materials have been used to expand the performance and to secure workability. However, when these composite sheets are composited, the entire surface is adhered by an adhesive material or an adhesive material, so that the characteristics of the sheet having high strength are restricted, and the expected performance characteristic width cannot be obtained. Although single-layer waterproof sheets with different characteristics are also separately constructed, there are still problems such as construction cost, construction period, and external damage to the sheet during construction. Therefore, in the conventional waterproof sheet of the composite structure,
We cannot secure sufficient response performance to changes in the ground foundation,
It has been difficult to ensure reliable safety that can cope with impact stress due to uncertain ground movement such as an earthquake and movement due to large ground movement.

[0003]

In the conventional waterproof sheet, a composite sheet made of different materials has a composite interface in which the composite interface is entirely adhered and has an adhesive structure, so that stress between sheets is restrained against external stress. Therefore, it was difficult to secure the characteristics of each composite sheet. In the case of large-scale water works, in order to cope with land changes that have many uncertain factors due to earthquakes, etc., the waterproof sheet has the following characteristics: In this case, both sides are required to have a long stretchability even though the strength is low. Needless to say, a single-layered waterproof sheet cannot meet such required characteristics even with a conventional composite adhesive sheet having full adhesion and adhesion. The problem to be solved by the present invention is a composite tarpaulin structure having a wide range of corresponding characteristics, which has many uncertainties, can deal with ground cracks and ground movement due to earthquakes, etc., does not impair workability, and is suitable for mass production. It is an appearance.

The problem to be solved by the invention is that the workability is equivalent to that of a single-layer waterproof sheet, it is resistant to external damage during construction, and after construction, it quickly responds to the stress generated during earthquakes and ground movements. The performance of the composite tarpaulin having a wide range of properties, and the leakage of the waterproof layer with a large area that is difficult to repair after the start of use, such as a water barrier in a waste disposal site, can be prevented by the adhesive interface of the composite tarpaulin. It is a waterproof sheet structure that can be used for a leak detection sensor that has durability reliability and economic efficiency by utilizing the parts.

[0005]

Means for Solving the Problems The present inventor has paid attention to the problems associated with the composite adhesion and the boundary layer of the adhesive surface of the conventional composite waterproof sheet, and as a result, has studied the bonding material of the boundary surface of the composite layer.
The non-drying adhesive material is used, and the composite sheet has a structure in which a sheet having a high elastic coefficient and a sheet having a low elastic coefficient are made to coexist with the adhesive material portion through the non-adhesive region, so that The present invention has been completed by discovering that the performance is fully exhibited, and by confirming that the continuous non-drying adhesive material portion can be utilized to fulfill the function of a leak detection sensor.

The present invention relates to a composite waterproof sheet composed of a rubber or polymer sheet, which has a high elastic modulus and a small elastic modulus, and a small elastic modulus and a large elastic modulus. When combining sheets, the characteristics of non-drying adhesive material, such as a small vertical peel force and a large shearing adhesive strength, are used to make the adhesive structure between each sheet continuous with the non-adhesive area. It was constructed by coexisting with the adhesive zone. With this structure, when a waterproof sheet is installed, it can be installed as a single-layer sheet due to the large adhesive strength of the non-drying adhesive in the shearing direction.When manufacturing a composite waterproof sheet, a sheet with a high elastic modulus and high tension is used as the liner. As a production form in which a sheet having a low elastic modulus is combined, a high-speed production becomes possible. Also, when installing the seam after laying the waterproof sheet, when welding the seam with a high elastic modulus sheet, for example, a high density polyethylene sheet as the lower layer, it is easy to use the upper low elastic modulus sheet, such as a rubber sheet. Can be folded back to ensure workability.

The non-drying adhesive material used in the present invention is preferably a tape-like material which is made of a polymer-based or rubber-asphalt-based material and which does not cause the material to be bonded to the composite sheet to be broken. A coated type may be used. In the composite sheet of the present invention, this non-drying adhesive material is always sandwiched between two sheets, and long-term performance retention is ensured. Therefore, even if a conductive filler is mixed in the adhesive material or a conductive metal material is compounded, long-term durability can be secured. Therefore, the function of the sensor for detecting the change of the waterproof sheet with respect to the external stress by the change of the electric resistance can be secured together.

[0008]

Operation When the composite waterproof sheet of the present invention is used in a water blocking work in which ground movement is likely to occur due to a large earthquake or the like, the operation will be described. A density polyethylene sheet of a high elastic modulus material is provided in parallel with the longitudinal direction of the sheet. In addition, a composite waterproof sheet having a structure in which multiple strips of non-drying adhesive tape at regular intervals are pasted and a rubber sheet of a low elastic modulus material is combined on it by roll pressure bonding, etc. On top of. When laying a sheet, the non-drying adhesive material provides the same workability as a single-layer sheet due to the strong shearing adhesive force. After laying the sheet on the ground foundation with the high elastic coefficient waterproof sheet as the lower surface, fold the low elastic coefficient waterproof sheet of the upper layer of the composite sheet at the seam of the sheet back to both sides and press the lower layer sheet with a sandbag etc. To wear. At this time, since the upper layer sheet is soft, the workability is not affected. After that, the seam treatment of the upper layer sheet is performed by welding or adhesion. Further, a protective layer is laid on the upper layer sheet. In this construction structure, the high-modulus, high-strength lower-layer sheet prevents external damage such as crushed stones and roots, which is a general condition in the ground, and the low-modulus upper-layer sheet has surface elasticity. Prevents damage to the protective layer by stretching due to crushed stone during construction.

[0009] In the composite waterproof sheet of the large water impeller constructed in this way, due to an earthquake or other causes,
When the base ground of the waterproof sheet is changed, the waterproof sheet has a weak adhesive force which is a characteristic of the vertical adhesive of the non-adhesive area used for the sheet composite boundary and the non-drying adhesive material provided side by side. Thus, the material characteristics of the lower layer or the upper layer of the composite waterproof sheet can be dealt with by partially deforming and peeling according to the situation so as to easily match the indefinite deformation of the ground foundation.

Further, the leak detection sensor of the waterproof sheet, which is being considered for large-scale water shield works, is directly embedded in the soil. In this case, it is difficult to guarantee long-term durability. In the case of the waterproof sheet of the present invention, the conductive non-drying adhesive material between the upper layer sheet and the lower layer sheet serves as a sensor due to a change in electric resistance, and thus the durability of the sensor portion is high. In the event of an earthquake or other ground deformation, changes in the electrical resistance can be determined using the non-drying adhesive material for the displacement and damage of the upper and lower sheets, so use the sketch of the construction drawing. By doing so, it can easily serve as a detection sensor.

[0011]

The present invention will be described in detail below with reference to the illustrated embodiments, but the present invention is not limited thereby. Example FIG. 1 is a perspective view of the structure of the composite waterproof sheet of the present invention. This structure is composed of a soft rubber sheet (1) with a low elastic modulus and a large elongation in the upper layer, a hard high-density polyethylene sheet (2) with a high elastic modulus and a high tensile strength and a small elongation at the yield point, and an upper sheet and a lower layer sheet. It is composed of a strip-shaped continuous non-drying adhesive material (3).
(4) is a non-adhesive portion between the composite sheets which is indispensable for the structure of the present invention and coexists with the adhesive portion of the composite sheet (3). (5) and (6) are indicated by vectors showing the magnitude of the adhesive force of the non-drying adhesive material of (3). The large difference in the adhesive force along with the function of the non-adhesive region (4) makes it possible to demonstrate the effect of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a composite waterproof sheet of the present invention has been used for a water blocking work, and after the waterproof sheet has been laid due to an earthquake or other causes, a large movement has occurred in the ground. Indicates. (12) is a moving foundation ground, (13) is a space between the waterproof sheet and the ground caused by the ground movement, (8)
A protective layer of a waterproof sheet in a water barrier work, (9) is a state of the upper layer of the waterproof sheet which is soft and has a large elongation, and has a low elastic coefficient, which follows the movement of the ground, and (10) is mixed with the ground soil. Crushed stones, (11) trees, bamboo roots, etc.

The operation of the demonstrative effect in the water blocking work model will be described with reference to FIGS. A rubber sheet having a thickness of 2 mm was used for (1), and a high density polyethylene sheet having a thickness of 1 mm was used for (2). For (3), a longitudinally stretch-restrained butyl rubber adhesive tape having a thickness of 1 mm was used. In (4), a non-adhesive region having a width of 1 m was taken, and the composite sheet had a width of 3 m and a length of 4 m. The protective layer in (8) had a thickness of 30 cm. In such a structure, the perimeter of the waterproof sheet is fixed to the frame, 2
As shown in the figure, when a load is applied from the side of the protective layer while escaping the ground soil, when the sheet of (2) breaks from the place where the cut was made in advance so as to easily break (1)
The swelling of the sheet from the upper layer caused expansion and closed the damaged part. According to this experiment, when the base ground is moved, the waterproof sheet has high strength and low elongation (2).
It was confirmed that the fractured part of (2) can be enclosed by the effect of the non-adhesive region, and the elongation is large due to the effect of the non-adhesive area. In addition, it was confirmed that the peeling of the adhesive part of (1) and (2) can be dealt with while matching the internal stress of the sheet that occurs as the movement of the ground foundation expands. If the adhesive material is made conductive, the resistance change I got the prospect that it can be used for the sensor. Further, an indoor test was conducted using the test method of ASTM D 3786 to verify the same effect when the high-density polyethylene sheet of (2) was broken.

[0014]

Since the present invention has the above-mentioned structure,
It has the following excellent effects. (A) By using the composite sheet of the present invention in a water blocking work such as a large-scale reservoir or a hazardous waste treatment plant, it is possible to obtain a waterproof sheet caused by an earthquake or other causes that cannot be solved by the conventional technology. Since it is possible to follow the large movement of the ground foundation, it is possible to remarkably improve the reliability for preventing the leakage of harmful waste liquid and the like. (B) Since a sheet having a high elastic modulus can be used also as a take-up liner in a composite production process, a high degree of productivity can be secured, which is economically advantageous. (C) Since the adhesive material part which plays the role of the composite adhesive of the upper layer sheet and the lower layer sheet can play the role of a sensor that can be expected to have long-term reliability, another sensor can be dispensed with and the economical efficiency and reliability can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a waterproof sheet of the present invention.

FIG. 2 is an effect cross-sectional view when the waterproof sheet of the present invention is used in a water barrier work.

[Explanation of symbols]

1 Low elastic coefficient waterproof sheet 2 High elastic coefficient waterproof sheet 3 Non-dry adhesive material 4 Non-adhesive area of composite boundary of waterproof sheet 5 Vector showing shear direction adhesive force of non-dry adhesive material 6 Vertical adhesion of non-dry adhesive material Vector representing force 7 Space created on the ground under the ground movement 8 Protective layer of waterproof sheet 9 High elastic modulus Deformation of low elastic sheet when waterproof sheet is damaged 10 Crushed stone in underlying layer 11 Roots of trees and bamboo 12 Movement of tarpaulin of waterproofing foundation ground 13 Space between waterproof sheet and ground

Claims (2)

[Claims] 1. A waterproof sheet in which a high elastic coefficient waterproof sheet and a low elastic coefficient waterproof sheet are combined with a non-drying adhesive material in a structure in which a non-adhesive area and an adhesive area are present together. 2. An adhesive composite in which a conductive filler or a conductive metal material is put into a continuous non-drying adhesive material to form an adhesive composite.
Composite tarpaulin.