JP2008223336A - Water cutoff material for underground structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water cutoff material for an underground structure, which can be applied to a location of the underground structure where no gap is formed, and is inexpensive and effective. <P>SOLUTION: The water cutoff material A is for use at the location of the underground structure, where no gap is formed, and prepared by mixing bentonite of 35 to 50 wt.%, a thermoplastic resin of 18 to 30%, a water absorbing resin of 2 to 9%, a plasticizer of 19 to 22%, and a powdered synthetic rubber of 4 to 6%, with each other. The water cutoff material exerts not only suitable rubber elasticity and excellent follow-up capability at the time of construction even at the location of the underground structure, where no gap is formed, but also adhesive strength and tensile strength at constant values or more, respectively. Therefore the water cutoff material is easily used in construction work, exerts quick-acting property, and exhibits long-term water-cutoff effect. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a waterproofing material that is attached to a portion where there is no gap in the underground structure, for example, a concrete joint or a joint of a formwork material, and blocks the water leak at the location where the leakage occurs in the underground structure to stop the leakage. It is about.

  When constructing a segment for an underground structure, for example, a tunnel, backfilling of the injection material is performed between the natural ground and this segment. Secondary water stop is necessary to prevent water leakage from the natural ground to the tunnel. Therefore, as shown in FIG. 6, the joint of the joint surfaces 22 and 22 on the two adjacent sides of the segment 21 which is a curved plate body and has a joint surface 22 with the edges of the four sides suspended for a certain length. At the time of connection, a water-stop material M is usually used, so that water cannot enter the segment 21.

  The water-stopping material M affixed to these joint surfaces 22 and 22 is compressed by the tightening force of the bolts and nuts when assembling the segments at the time of construction, and the water-stopping material M is stopped by the elastic repulsive force of the water-stopping material M. Do water. Even if the seam opens at the seam at a later date and the elastic repulsion force decreases, as shown in FIG. 7, when water is absorbed, it self-expands and a force that expands in the direction of the arrow acts. If the surface stress σ due to this elastic repulsion force or self-expansion is greater than the water pressure P applied from the outside of the segment, the water stop function is maintained. That is, the basic condition of water stoppage due to the packing effect is that the contact stress σ> water pressure P.

  Currently, a water-stopping material obtained by mixing a vulcanized rubber (chloroprene rubber or the like) with a water-absorbing resin or the like is often used as a water-stopping material for the underground structure. However, these water-stopping materials have a large reaction force and expansion pressure accompanying compression, and sometimes have an adverse effect on underground structures. For this reason, the applicant of the present application has developed a new water-stopping material that has bentonite, which is an inorganic clay mineral, as the main component, minimizing these adverse effects.

This bentonite-based water-stopping material solves the problems of conventional products, is inexpensive, has excellent durability, has high swelling performance, and has excellent followability after expansion. As a result, it is highly reliable as a water stop material.
JP 2006-57275 A

However, further reductions in product price, expansion of applications, and review of more effective formulations are unavoidable for companies, and earnestly require research and development.
On the other hand, at locations where there are no gaps in the underground structure, such as concrete joints, the adhesive strength and tensile strength to the location where the water is to be stopped are required rather than the expansion rate of the water-stopping material.

  Therefore, in view of these problems, the present invention provides a new inexpensive and effective waterproofing material for an underground structure that can be effectively used in a place where there is no gap in the underground structure. As used herein, a portion having no gap means a portion having almost no gap or substantially no gap, and is not a portion having no gap.

  The invention of claim 1 is a water stop material used in a place where there is no gap in the underground structure, 35-50% by weight of bentonite, 18-30% of thermoplastic resin, 2-9% of water absorbent resin, A waterproofing material for underground structures formed by blending 19 to 22% of plasticizer and 4 to 6% of powdered synthetic rubber was obtained.

  The invention according to claim 2 is the water-stopping material for underground structures according to claim 1, wherein the water-stopping material has an adhesive tape shape, a band shape, or a sheet shape. The invention according to claim 3 is the underground structure according to any one of claims 1 to 2, wherein the water-stopping material is used as a water-stopping material for seams when performing concrete casting without providing a gap. A waterstop material was used.

  According to a fourth aspect of the present invention, the water-stopping material is used as a water-stopping material that closes the crack of a cracked pipe, for example, a centrifugal reinforced concrete pipe (so-called fume pipe, hereinafter referred to as “fume pipe”). The water-stopping material for underground structures according to any one of claims 1 to 2. Further, the invention according to claim 5 is that the water-stopping material is a plurality of concrete placement pots used when constructing the box culvert without excavation in manholes or caves in the method of constructing the box culvert by the open-cut method. The water-stopping material for underground structures according to any one of claims 1 to 2, which is used as a water-stopping material for joints between the formwork materials.

  According to the inventions of claims 1, 2, 3, 4 and 5, in a place where there is no gap in the underground structure, in addition to appropriate rubber elasticity, excellent followability during construction, Since it has tensile strength, it is easy to install and has immediate effect. Moreover, even if a gap is generated at the joint of the underground structure due to the change of the underground structure after construction, the gap is closed due to the followability due to the expansion of the water-stopping material. Furthermore, even if a crack or the like occurs in the water-stopping material, the water-stopping function can be maintained by self-sealing. Therefore, the water can be reliably and stably stopped for a long time.

  While exhibiting such an excellent water-stopping effect, it is inexpensive because it uses bentonite and can be widely used for water-stopping in underground structures, greatly contributing to a reduction in construction costs. In addition, bentonite used in this water-stopping material is stable for a long time because it does not deteriorate or rot, and has excellent performance such as excellent durability because it does not decrease expandability due to repeated water absorption and drying. .

  Further, according to the invention of claim 2, since the water-stopping material is in the form of an adhesive tape, a band or a sheet, it is more reliable only by sticking to the water-stop portion from above. In addition, the water can be stably stopped.

  This invention is a waterproofing material used in a place where there is no gap in the underground structure, 35-50% by weight of bentonite, 18-30% of thermoplastic resin, 2-9% of water-absorbing resin, and plasticizer It is a waterproofing material for underground structures formed by blending 19 to 22% and 4 to 6% of powdered synthetic rubber. Even if there are no gaps in the underground structure, moderate rubber elasticity, during construction In addition to the excellent followability, the adhesive strength and the tensile strength are more than a certain value, so that the construction is easy, has an immediate effect, and can be reliably and stably stopped for a long time.

Embodiments of the present invention will be described below with reference to the drawings.
The waterstop material of the present invention is mainly molded from bentonite, thermoplastic resin, water-absorbing resin, plasticizer, and powdered synthetic rubber, and these are blended and molded. Bentonite is mainly composed of montmorillonite, and it is formulated for the purpose of exhibiting properties such as swelling, water-stopping properties, and adhesiveness. descend. The molded water-stopping material is in a state where bentonite particles are uniformly dispersed in particles such as the thermoplastic resin.

  The thermoplastic resin (TPR) has rubber elasticity at room temperature but plasticizes at high temperature. Therefore, this water-stopping material is used by mixing with other materials after high-temperature heating for the purpose of exerting elastic force. . Depending on the main component of this thermoplastic resin, olefin (TPO), styrene (TPS), diene, ester (TPEE), urethane (TPU), amide (TPEA), vinyl chloride (TPVC), etc. There are many types available. Examples of the styrene resin include SEEP type, and examples of the diene resin include 1,3-pentadiene.

  The water-absorbent resin is basically the same as that used for a general water-swelling water-stopping material, and is blended with the expectation of swelling performance. In view of swelling speed and hardness after swelling, polyethylene oxide (PEO) is used here. However, the water absorbent resin is not limited to polyethylene oxide (PEO).

  The plasticizer is generally called process oil, and is a kind of oil obtained by refining petroleum, and by blending it in the thermoplastic resin, it facilitates its workability, or Although it mix | blends in order to provide a softness | flexibility, the kind of plasticizer is limited for every kind of synthetic resin.

  As the powder synthetic rubber, butyl rubber and other synthetic rubbers are used.

  Although a water-stopping material can be obtained by mixing these blends, it is desirable to mix them sufficiently so that the particles of each blend are uniform. Moreover, in order to improve the properties of this water-stopping material, various additives that have been used in conventional water-stopping materials can be blended as necessary. Examples of the additive include softeners (mineral oil, synthetic oil, fatty oil, etc.), stabilizers (surfactants, amines, phenols, etc.), antioxidants, colorants, fillers and the like.

  The method of forming this water-stopping material is the same as that of a conventional water-stopping material, and an extrusion molding method, a press molding method, or the like can be used. Moreover, although the shape of the water stop material shape | molded here is various, while selecting the shape from which sufficient water stop function is obtained, it is desirable to select the optimal shape which does not interfere with construction.

Next, the compounding example of these main raw materials is shown.
The blending example of the waterstop material of this example is 35-50% by weight of bentonite, 18-30% of thermoplastic resin, 2-9% of water absorbent resin, 19-22% of plasticizer, and powdered synthetic rubber. It was formed by blending 4 to 6%.

  Here, as a sample of the example, sample No. 11, Sample No. 17, Sample No. 19 and sample no. Four of 20 were molded. Table 1 shows the composition (% by weight) for each specific sample in these examples. In addition, the water stop performance of the samples in Table 1 was measured in the water stop performance list in Table 2.

  According to Table 2, it was found that all the examples had a water pressure resistance of 1.0 Mpa or more and could withstand a water pressure of 100 m below the ground water surface.

  In addition, the surface stress is generated by the restoring force and elastic repulsive force of the water stop material in the short term, and the water stop material may expand in the long term. It is a water stop material used at a location, and it is considered that the point due to the adhesive strength and tensile strength of the water stop material itself is larger than the expansion.

Next, the adhesive strength measured the tensile shear strength with respect to the said steel plate adhesion | attachment at the time of sticking a water stop material on the steel plate using the adhesive agent ("Konishi Bond G10Z" by Konishi Co., Ltd.). As a result, as shown in Table 2, the sample No. 11 is 0.24 N / mm ² , Sample No. 17 is 0.10 N / mm ² , sample no. 19 is 0.10 N / mm ² , and sample no. 20 was 0.30 N / mm ² .

  At the right end of Table 2, for comparison, data on the water stop material of Japanese Patent Application No. 2006-57275 filed earlier by the applicant of the present application is shown as a comparative example.

In the adhesive strength, the comparative example was 0.02 to 0.03 N / mm ² , whereas each example was found to have an adhesive strength approximately 3 to 15 times that of the comparative example. In addition, the blend of the comparative example was formed by blending 30 to 40% by weight of bentonite, 30 to 35% of a thermoplastic resin, 5 to 15% of a water absorbent resin, and 15 to 20% of a plasticizer. In this comparative example, the powdered synthetic rubber is not used.

Next, the tensile strength was measured. Sample No. 11 is 4.3 N / mm ² , sample no. 17 is 2.0 N / mm ² , sample no. 19 is 2.1 N / mm ² and sample no. 20 was 2.2 N / mm ² , and the comparative example was 0.86 to 1.08 N / mm ² . As a result, it was found that each example had a tensile strength approximately 2 to 5 times that of the comparative example.

By the above, the sample, the adhesion strength of approximately 0.1~0.3N / mm ^2, and the tensile strength have each 2.0~4.3N / mm ^2, also, than Comparative Example 3-15 Because it has double adhesive strength and 2-5 times tensile strength, it has good workability, has immediate effect, and has a long-term effect due to durability. It is suitable as a water material. In particular, sample No. 17 is the most suitable because it has a good balance of water pressure resistance, adhesive strength and tensile strength.

  FIG. 1 is a cross-sectional view of a state in which a water-stopping material according to an embodiment of the present invention is used in a concrete joint in an open-cut method. Sample No. The water-stopping material A formed from 17 was used as the water-stopping material A at the joint of the concrete 1. In this case, after placing the lower concrete 1, the said concrete 1 is cast, and the water-stopping material A is bonded and fixed to the upper edge of the solidified concrete 1, and the upper concrete 1 is poured from above and cast. The joints of these concretes 1 are stopped.

Conventionally, in order to provide a water-stopping material at the joint of concrete, it has been pushed into concrete that has not yet solidified immediately after being placed so that only the lower part of the band-shaped water-stopping material is buried at a right angle. It took a long time to provide a water-stopping material on the concrete that was not solidified, and could not be easily provided.
In this invention, since the water-stopping material is applied on the solidified concrete, it can be easily bonded and fixed on the concrete, and the working time can be greatly shortened.

  Further, this water-stopping material can be used in the form of an adhesive tape having adhesiveness, and in this case, it is more efficient if it is formed into a double-sided tape. Furthermore, it can also be used in the form of a strip or sheet. FIG. 2 is a side view showing a state in which the water-stopping material of the embodiment of the present invention is used as a water-stopping tape B by being attached to the side face of the joint 1 of the concrete 1.

  Further, FIG. 3 is a side view showing a state in which the water-stopping material of the embodiment of the present invention is used as a water-stopping tape C for a joint between the formwork materials 2 for placing concrete. This sample No. In the method of constructing a box culvert by the excavation method described in Japanese Patent No. 2969607 using No. 17, as shown in FIG. It can also be used as a waterproofing tape C for joints between a plurality of formwork materials 2 for concrete placement.

  Moreover, when a crack is generated in a pipe buried underground, it can be used as a pipe repair tape. FIG. 4 is an explanatory diagram of a state where the water-stopping material of the embodiment of the present invention is used as a pipe repair tape and used for water-stopping of cracks generated in the fume pipe 4, and FIG. 4 (a) is a side view. FIG. 4B is a front view. As shown in FIG. 4, when a crack 5 is generated on the outer periphery of the fumed pipe 4 through which the cable 3 is inserted, the pipe repair tape D formed in the tape shape is wound around the outer side of the fumed pipe 4. A state in which the crack 5 is repaired by rotating it so as to close the crack 5 is shown. After this, in order to reinforce the structure, there is a case in which a body-clamping concrete is placed on the outer periphery.

  And when using as the pipe repair tape D, there is also a method of fixing to the fume pipe 4 as follows. By applying an adhesive to the entire back surface of the water-stopping material and sticking it to the fume tube, sticking both ends of the water-stopping material wrapped around the fume tube (adhesion with double-sided butyl tape), or a binding band, This is a method of fixing without using an adhesive. Further, when the pipe repair tape D, which is a water-stopping material, is spirally wound around the fume pipe 4 without applying an adhesive on the back surface of the water-stopping material provided in a tape shape, as shown in FIG. The adhesive repairing material E is filled in the gap where the pipe repair tapes D are overlapped, and the pipe is closed.

  Also, pipes for repairing cracks using the pipe repair tape D include reinforced concrete pipes such as the fume pipes, prestressed concrete pipes, ceramic pipes, asbestos cement pipes, etc., and cracks occur in the pipe body. , All tube types that can seal cracks by applying this water-stopping material from above are targeted.

It is sectional drawing of the state which used the water stop material of the Example of this invention for the joint joint of the concrete in an open-cut method. It is a side view of the state which is using the water stop material of the Example of this invention for the side of the joint of concrete as a water stop tape. It is a side view of the state which is used for the joint of the some formwork material for concrete placement as the water stop material of the Example of this invention as a water stop tape. (A) It is a side view of the state which uses the water stop material of the Example of this invention as the HP repair tape, and is used for the water stop of the crack which generate | occur | produced in the fume pipe | tube. (B) It is a front view of the state which uses the water stop material of the Example of this invention as the HP repair tape, and is used for the water stop of the crack which generate | occur | produced in the fume pipe | tube. The water-stopping material of the embodiment of the present invention is provided in a tape shape, the water-stopping material is spirally wound around a fume tube, and a state where the gap between the water-stopping materials overlaps is filled and sealed. It is a conceptual diagram. It is a perspective view which shows the state which affixed the water stop material on the segment. It is explanatory drawing which shows the surface pressure (sigma)> water pressure P by the restoring force of a water stop material, an elastic repulsive force, and expansion which are the basic conditions of water stop.

Explanation of symbols

A Water-stopping material B Water-stopping tape C Water-stopping tape D Pipe repair tape E Adhesive 1 Concrete 2 Formwork material for placing concrete 3 Cable 4 Hume pipe 5 Crack

Claims (5)

It is a waterproofing material used in places where there are no gaps in underground structures,
35-50% by weight of bentonite, 18-30% of thermoplastic resin, 2-9% of water absorbent resin, 19-22% of plasticizer, 4-6% of powdered synthetic rubber A waterproofing material for underground structures. The water-stopping material for underground structures according to claim 1, wherein the water-stopping material has an adhesive tape shape, a band shape, or a sheet shape. The water-stopping material for underground structures according to any one of claims 1 to 2, wherein the water-stopping material is used as a water-stopping material for seams when concrete is cast without providing a gap. . The water-stopping material for underground structures according to any one of claims 1 to 2, wherein the water-stopping material is used as a water-stopping material that closes the crack of a pipe in which a crack has occurred. The water-stop material is a joint stop between a plurality of formwork materials for placing concrete used in the construction of the box culvert without overexcavation in a manhole or a cave in a method of constructing the box culvert by an open-cut method. The waterstop material for underground structures according to any one of claims 1 to 2, wherein the waterstop material is used as a water material.

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