Tunnel Segment Gasket, also called of shield segment sealing rod, is one of the most effective waterproof material for joint of segment assembly under shield tunneling construction. According to its function, tunnel segment gasket can be classified into elastomeric gasket type, hydrophilic gasket type and compound of elastomeric and hydrophilic gasket type.
Tunnel segment gasket is made of extruded EPDM | Elastomeric tunnel segment gasket porous type |
Tunnel Segment Gasket Types
Elastomeric tunnel segment gasket is made of neoprene rubber(CR) or EPDM rubber. Cause EPDM rubber has strong chemical stability, electrical insulation, excellent weather resistance, water resistance and ozone resistance, at the same time, porous type gasket can reduce the compressive stress during assembly and prolong its service lifetime. So that EPDM tunnel segment gasket with porous type is the main materials used for sealing water of assembled tunnel segments at home and abroad.
Physical Performance of Elastomeric Tunnel Segment |
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Item |
Index |
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CR |
EPDM |
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Ⅰ Type |
Ⅱ Type |
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Hardness(Shore A)/Durometer |
50-60 |
50-60 |
60-70 |
|
Hardness Deviation/Durometer |
± 5 |
± 5 |
± 5 |
|
Tensile Strength/MPa ≥ |
10.5 |
9.5 |
10 |
|
Elongation at Break/% ≥ |
350 |
350 |
330 |
|
Compression Set/% |
70℃ × 24 h, 25% ≤ |
30 |
25 |
25 |
23℃ × 72 h, 25% ≤ |
20 |
20 |
15 |
|
Hot Air Aging 70℃ × 96 h, |
Hardness Change/Durometer ≤ |
8 |
6 |
6 |
Decrease Rate of Tensile Strength ≤ |
20 |
13 |
15 |
|
Decrease Rate of Tensile Strength ≤ |
30 |
30 |
30 |
|
Grade of Mildew Proof |
Not less than grade 2 |
Not less than grade 2 |
Not less than grade 2 |
|
Ⅰ Type is without hole type gasket, Ⅱ Type is with |
Physical Performance of Hydrophilic Tunnel Segment Gasket’s Rubber Compound |
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Item |
Technical Index |
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Hardness(Shore A)/Durometer |
42 ± 10 |
45 ± 10 |
|
Tensile Strength/MPa ≥ |
3.5 |
3 |
|
Elongation at Break/% ≥ |
450 |
350 |
|
Volume Expansion Rate/% ≥ |
250 |
400 |
|
Repeated immersion test |
Tensile Strength/MPa ≥ |
3 |
2 |
Elongation at Break/% ≥ |
350 |
250 |
|
Volume Expansion Rate/% ≥ |
250 |
300 |
|
Bending at Low Temperature (-20℃ × |
No Cracks |
No Cracks |
This type of tunnel segment gasket is consisted of extruded rubber with a hydrophilic sealing insert. The cell structure allows the gasket to be compressed as the segments are installed and pushed together during installation of a lining ring. And hydrophilic sealing inserts will swell automatically in contact with moisture or water. So this type of tunnel segment gasket has excellent water stopping performance.
The elastomeric part shall confirm to the elastomeric tunnel segment gasket physical properties. Hydrophilic sealing insert shall confirm to the hydrophilic segment gasket physical properties.
Tunnel Segment Gasket Section Type
Type | Specification | Section View |
BL-1 | 47*16.5 | |
BL-2 | 47*16.5 | |
BL-3 | 47*19.5 | |
BL-4 | 35*17 | |
BL-5 | 35*20 | |
BL-6 | 22*10.5 |
Tunnel Segment Connecting Corner
BAOLI produce the connecting corners according to each tunnel segment gasket.
Tunnel Segment Gasket Production
Machine for making tunnel segment gasket | Tunnel segment gasket through cooling system |
Tunnel Segment Gasket Production Packing
Tunnel segment gasket before packing | Tunnel segment gasket marks |
Tunnel segment gasket in roll | Tunnel segment gasket on wooden pallet |
Tunnel Segment Gasket Application
Tunnel segment gasket installed in tunnel segment |