JPH028438A - Composite sealing material - Google Patents

Abstract

PURPOSE:To obtain a composite sealing material capable of maintaining the better watertightness over an extended period of time by applying a water swelling elastomer to a groove in a contact section of a seal body of a non- water swelling elastomer. CONSTITUTION:A water swelling elastomer 14 is applied to a groove 12 in a contact section which is a seal part of a seal body 11 of a non-water swelling elastomer. Most part of such a composite sealing material 10 is constituted of the non-water swelling elastomer, so that contact surface compressive reaction force necessary for watertightness is obtained, and, at the same time, a water leakage in the early submersion is prevented. An amount of compressive deformation of the sealing material 10 is reduced by the water swelling elastomer 14 of the groove 12, so that it is prevented to act strong compressive reaction force on a structure to eliminate unloadings. Accordingly, the better watertightness can be maintained over an extended period of time.

Description

[Detailed Description of the Invention] Sou 1 = Suushi Tomoyoshi 1 The present invention relates to a sealing material for structures whose joint parts come into contact with rainwater, rivers, seawater, etc., and particularly relates to a sealing material for sealing joints in concrete structures. be.

The sealing material 01 is made of a non-water-swellable elastomer such as rubber or soft synthetic resin that does not expand even when it comes in contact with water, as shown in FIG. It maintains watertightness and hangs due to the flexural compression reaction force.

However, in the sealing material 01 shown in FIG. 1, since the amount of compressive deformation is large in order to obtain sufficient watertightness, the reaction force is large. When one segment 02a moves relative to the other segment 02b and is assembled, a large frictional force acts between the sealing materials 01a and 01b, or the sealing materials 01a and 01b are caught on each other. , the seal members 01a and 01b are more likely to fall off than the segments 02a and 02b, and the seal 101a is more likely to fall off due to the pressure generated by the jacking of the shield machine during tunnel excavation.

01b undergoes large repeated compressive deformation, and the sealing material 01a
, Olb was prone to sagging.

Furthermore, it was difficult to reduce the opening between the segments 02a and 02b due to the large compression reaction force acting on the sealing materials 01a and 01b.

Furthermore, after the segment is installed, the contact surface compression reaction force decreases due to stress relaxation (a phenomenon in which the stress corresponding to the amount of deformation gradually decreases over time), so water leakage may occur several years after construction. If this occurs, or if the openings occur due to ground subsidence, it may become impossible to follow the openings and it may become impossible to maintain watertightness.

In addition, the sealing material 03 is made of a water-swellable elastomer such as a new water-based polyurethane resin, polyvinyl alcohol resin, acrylic acid polymer resin, maleic anhydride copolymer resin, etc., which can expand upon contact with water, as shown in FIG. In addition, when the segment is not in contact with water, the amount of compression when assembling the segment is smaller than that of non-water-swellable Exmers, and as a result, the workability is excellent, but on the other hand, the contact surface compression reaction force is Because of the low height, water leaks easily at the initial stage of flooding, and also when openings occur or the segments are relatively displaced.

Furthermore, the strength of water-swellable elastomers is about 1/10 lower than that of non-water-swellable elastomers, and during the application of the sealant, the sealant 03 is slightly stretched, so the sealant will not stretch. Due to the decrease in height,
Watertightness is not good.

Furthermore, after assembling the segments, a backfilling injection agent is injected to stabilize the ground, but in areas where the pressure is high, 10KFj
/cM, and as a result, in the case of segments without grooves, the sealing material 03 may be pushed in and deformed or broken, leaking from segment 1~ and unable to perform its watertight function. .

Moreover, water-swellable elastomers are inferior to non-water-swellable ex-1~mers in terms of physical properties such as strength and elasticity, so if their physical properties deteriorate even slightly due to aging, it will be fatal as a sealing material. easy.

And since the water aqueous elastomer has no directionality, the second
When the sealing material 03 shown in the figure comes into contact with water and swells, it cannot swell significantly in the direction in which the two sealing materials 03a and 03b come into pressure contact with each other due to the compression reaction force of the contact surfaces, and the sealing material 03 shown in FIG. As it swells in a direction perpendicular to this direction with little resistance, no contact surface compression reaction force large enough to counteract the pressure of external water seepage is generated, ensuring reliable watertightness. I can't do it.

In order to improve this point, as shown in FIG. 4, the water-swellable elastomer 04 contains a core material 05, or as shown in FIGS. 5 to 7, the water-swellable elastomer 04 is There is a product in which a restraining material O6 is attached to the required surface, but with this structure, the expansion effect in the direction perpendicular to the sealing material surface can be enhanced, but the water-swellable elastomer 04 is Since it does not expand unless touched, water leakage cannot be prevented at the initial stage of flooding, and it may not be possible to maintain reliable watertightness for a long period of time.

The present invention relates to an improvement of a composite sealing material that overcomes these difficulties, and in which a water-swellable elastomer is attached to a concave portion of a sealing portion of a seal body made of a non-water-swellable elastomer. It is characterized by this.

In the present invention, most of the sealing material is made of non-water-swellable elastomer, so even if the sealing material does not come into contact with water, the contact surface compression reaction force necessary for watertightness can be obtained, and water leakage at the initial stage of flooding can be prevented. be done.

In addition, in the present invention, water-swellable elastomer is attached to four parts of the seal portion of the seal body made of non-water-swellable elastomer, so the amount of compressive deformation is reduced compared to a sealing material made only of non-water-swellable elastomer. The reaction force can be reduced, a large compressive reaction force can be prevented from acting on the structure to which the sealing material is applied, and openings can be prevented as much as possible.

Furthermore, in the present invention, since the contact surface compression reaction force acting on the sealing material is small, the stress relaxation phenomenon is less likely to occur, and good watertightness can be maintained for a long period of time.

Furthermore, in the present invention, since the water-swellable elastomer is integrally attached in advance to the concave portion of the sealing part of the seal body made of a non-water-swellable elastomer, unlike the sealing material made of a water-swellable elastomer alone, the water-swellable elastomer is attached during construction. It is possible to prevent "thinning" due to expansion of the sealing material and breakage of the sealing material due to backfill injection compressive force, and moreover, it is possible to efficiently perform II in a short time.

Moreover, in the present invention, even if the water-swellable elastomer attached to the concave portion of the seal portion of the seal body deteriorates and loses its water-stop function, the seal body is made of a non-water-swellable elastomer, so a large amount of water leaks. The situation can be avoided.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention illustrated in FIGS. 8 to 10 will now be described.

Segment 1a for a shield tunnel laid under the sea
, 1b are respectively formed with recesses 3a, 3b having trapezoidal cross-sections oriented in the vertical direction.

The sealing material 10 attached to the recessed portion 3 of the segment 1 includes a non-water-swellable seal body 11 that is highly elastic and lυ, and a water-swellable material 14 attached to the bottom of the groove portion 12 having a ladder-shaped cross section of this seal body 11. This water-swellable material 14 has a thickness of about 2/3 of the depth of the groove portion 12.

Further, the seal body 11 is made of vulcanized rubber, a thermoplastic resin such as vinyl chloride resin, EPDM, SBS, etc., and the water-swellable material 14 is hydrophilic to these non-water-swellable elastomers. It is constructed by blending organic swelling compounds such as polyurethane resin, polyvinyl alcohol resin, acrylic acid polymer resin, and isobutylene-maleic anhydride copolymer resin.

The embodiment shown in FIGS. 8 to 10 is constructed as described above so that when each side wall 2a, 2b of segment 1a, 1b is laid in the sea, the
, Ib approach each other, and the seal bodies 11a, 11
The ninth contact portion 13a and 13b of b are mutually compressed.
The contact portion 13a is elastically deformed as shown in the figure.
A compressive reaction force necessary to maintain watertightness is generated in 13b.

Therefore, even if water does not enter the joint 4 between the side walls 2a and 2b, the joint 4 has sufficient watertightness and will not leak.

In addition, the seal body 11a, the contact portion 13a of llb,
13b, the contact surface compressive reaction force is reduced due to stress relaxation, and at the location where water has entered the joint 4, the contact portions 13a, 1
Even if water penetrates into the space 15 between the water-swellable materials 14a and 14b through the gap between the water-swellable materials 14a and 14b, the water-swellable materials 14a and 14b swell as shown in FIG. Since the compressive force necessary to maintain mutual watertightness works,
Can prevent initial water leakage.

This phenomenon is illustrated in FIG. 11, and in the conventional water-swellable sealing material 03 illustrated in FIGS. 2 and 3, the contact required for maintaining watertightness is A period T1 occurs during which the contact surface compression reaction force is lower than the surface compression reaction force, and initial water leakage occurs during this period, but in this example, the contact surface compression reaction force is as shown by curve 81 in FIG. Although it gradually decreases, it is always maintained higher than the contact surface compression reaction force required to maintain watertightness.

Furthermore, when the segments Ia and 1b open and the opening displacement X is small, as shown in FIG. 12,
Conventional water-swellable seal 03 shown in FIGS. 2 and 3
In this case, the contact surface compression reaction force changes as shown by curve A2, and water leakage occurs for 12 hours, but in the composite sealing material 10 of this example, the contact surface compression reaction force changes as shown by curve 82. The change will occur and no leakage will occur. In addition, non-water-swellable sealing materials 01, such as rubber and soft synthetic resins that do not expand even when they come in contact with water, are highly elastic and have a large initial contact surface compression reaction force. It is higher than the contact surface compression reaction force, and no water leakage occurs.

When the opening displacement X further increases, the contact surface compression reaction force of the conventional water-swellable sealing material 03 changes as shown by the A3 curve in FIG. Although the sealing material also causes water leakage, the leakage time is as short as t3. As shown in curve C3 in Figure 13, the contact surface compression reaction force of the conventional non-water-swellable sealing material 01 decreases over time to less than the contact surface compression reaction force required to maintain watertightness. Once a water leak occurs, the leak cannot be stopped.

Furthermore, FIG. 14 shows the state of stress relaxation after a long period of time after installing these sealing materials, and the contact surface compression reaction force changes as shown by the B4.04 curve, and in this example,
Even if water leakage occurs, the contact surface compression reaction force recovers and the leakage can be stopped, but with the conventional non-water-swellable sealing material 01, once water leakage occurs, the leakage cannot be stopped.

In the embodiment illustrated in FIGS. 8 to 10, the water-swellable material 1
The surface of No. 4 was flat, but as shown in Fig. 15,
The surface of the water-swellable material 14 may be formed into a concave shape so that both edges of the water-swellable material 14 match the outer edges of the groove portion 12. In such an embodiment, as shown in FIG. 10a in the recesses 3a and 3b of 1a and 1b,
10b is attached, and when water enters the convex lens-shaped space 15, the water evenly spreads over the entire water-swellable material 14, and the parts near both ends of the water-swellable material 14 are pressed against each other, rapidly When the water leakage stops, this sealed space 15
The water inside will not evaporate, and the central portion of the water-swellable material 14 will not shrink. This embodiment is particularly suitable for tunnels and communication cable tunnels where initial water leakage is a problem.

Alternatively, grooves 12 may be formed on both side surfaces of the sill body 11 as shown in FIGS. 17 and 18, and the water temperature material 14 within the grooves 12 may be formed in a concave shape as shown in FIG. good.

Further, in the above embodiments, the surface of the water-swellable material 14 is lower than the surface of the contact portion 13 of the seal body 11, but as shown in FIG. 14 may be formed on the same plane.

Furthermore, as shown in FIG. 20, the water-swellable material 14 may be made to protrude outward from the surface of the contact portion 13.

Furthermore, as shown in FIG. 21, a plurality of grooves 12 may be formed on the surface of the seal body 11, and a water swelling material 14 may be attached to each of the grooves 12.

Furthermore, if the direction of water inflow is determined and you want to stop water leakage early, a groove 12 is formed on the water ingress side as shown in FIG. 22, and a water swelling material 14 is attached to this groove 12. You may.

Furthermore, the sealing material 10 may be configured by combining each of these embodiments.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional non-water swellable sealant applied to both segments of a structure, and Figures 2 and 3 are a cross-sectional view of a conventional non-water swellable sealant applied to both segments of a structure. Fig. 2 shows the unswollen state, Fig. 3 shows the swollen state, and Figs. 4 to 7 are cross-sectional views of the conventional Haku sealing material. Figure 8 is a cross-sectional view of an embodiment of the composite sealing material according to the present invention;
Figures 9 and 10 are cross-sectional views of the composite sealing material applied to both segments of the structure; Figure 9 shows the unswollen state, Figure 10 shows the swollen state, and Figure 11 shows the swollen state. A characteristic diagram illustrating how the contact surface compression reaction force of the above embodiment and the conventional non-water swellable sil material changes over time;
Figures 12 and 13 are characteristic diagrams illustrating how the contact surface compression reaction force changes over time when the opening displacement between segments is small and large, and Figure 14 is a stress relaxation state. FIG. 15 is a cross-sectional view illustrating an embodiment of the present invention; FIG. 16 is a cross-sectional view when this embodiment is attached between segments and water infiltrates;
17 and 18 are cross-sectional views of an embodiment of the present invention in which grooves are formed on both sides of the seal body and a water-swelling material is attached to the grooves, and FIGS. 19 to 22 respectively show the present invention. FIG. 7 is a cross-sectional view of another embodiment. DESCRIPTION OF SYMBOLS 1... Segment, 2... Side wall, 3... Recessed part, 4
... joint, 5 ... space, 10 ... sealing material, 11 ... seal body, 12 ...
・Groove portion, 13... Contact portion, 14... Water swelling property, 15
···space.

Claims (1)

[Claims] A composite seal material characterized in that a water-swellable elastomer is attached to a concave portion of a seal portion of a seal body made of a non-water-swellable elastomer.