Tunnels — NATM • TBM • Cut & Cover • Immersed Tube

Xypex Waterproofing
& Enhanced Durability
for Tunnels

Xypex Crystalline Technology works inside the concrete. It waterproofs under extreme hydrostatic pressure, extends service life, and self-heals when water is present.

Trusted in over 110 countries for more than 55 years
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Xypex Crystalline Technology

Integral Waterproofing
& Increased Service Life

Xypex reacts with the by-products of cement hydration and water to form a non-soluble crystalline structure deep within the concrete. The concrete becomes impermeable to water — preventing penetration from any direction, even under extreme hydrostatic pressure.

The chemical-resistant crystalline matrix prevents chloride ingress and mitigates sulphate attack. It has also proven effective against carbonation and can self-heal static cracks up to 0.5 mm, ensuring long-term concrete performance under harsh environmental conditions.

Reactivates and self-heals cracks up to 0.5 mm when water is present

Extended service life

Waterproof under extreme hydrostatic pressure

The Xypex Advantages

  • ✓Permanent increase in durability and extended service life
  • ✓Protects against chlorides, sulphate attack and carbonation
  • ✓Permanently seals concrete from water ingress
  • ✓Self-heals static cracks up to 0.5 mm
  • ✓Lower carbon footprint than other waterproofing technologies
  • ✓Suitable for all types of tunnel construction
Waterproofing in Tunnels — Xypex vs Traditional

Fewer Layers, Fewer Processes.
Less Time, Less Risk, Less Cost.

Traditional surface-applied waterproofing membranes provide a thin, impermeable barrier that can be punctured during construction, may delaminate, and can fail within the structure's service life. Xypex works differently — integrated directly into the concrete mix or applied to the surface, it becomes a permanent part of the matrix.

Hammersmith Connection Tunnel

Thames Tideway, London, UK

Xypex was the sole waterproofing material. Xypex enabled an 11-week reduction in schedule.

Xypex Reduces the Construction Schedule

Traditional SCL with Sprayed Membrane
Primary Lining Construction
Primary Lining Preparation Including Leak Sealing
Secondary Lining Regulation
Spray Membrane Application (Full Circumference)
Membrane Protection Slab
Secondary Lining Construction
6 Activities 52 Weeks
vs.
Xypex Waterproofing
Primary Lining Construction
Primary Lining Preparation
Secondary Lining Construction
3 Activities 41 Weeks
11 weeks faster

The Xypex Tunnelling Advantages

  • ✓Shortens construction time and saves money
  • ✓Suitable for use in aggressive soils and groundwater
  • ✓Permanent increase in durability and extends service life
  • ✓Compatible with ground freezing methods
  • ✓Designed for greater efficiency with nozzle-added accelerators
  • ✓Suitable for all types of tunnel construction
  • ✓Self-heals static cracks up to 0.5 mm
  • ✓Globally available
Extended Service Life

Engineered for
Superior Performance

Concrete permeability is the primary predictor of service life in concrete infrastructure. It is directly related to the rate of deterioration from chloride-induced corrosion, sulphate attack, and carbonation.

Xypex Crystalline Technology reduces concrete permeability within its microstructure. Global independent testing confirms consistent, measurable performance improvement.

86.7%
Permeability Reduction
At 360 days — 11-year independent study
100+ yrs
Service Life Without Repair
Verified real-world, marine structures
50%
Corrosion Rate Reduction
In cracked concrete — independent testing
Xypex's integral waterproofing extends the active service life of tunnel structures, increases the time to first repair, and lowers total lifecycle costs — critical factors for infrastructure requiring a service life of 100+ years.

Competitive Validation

AVO II · €900M
Américo Vespucio
Oriente II
Santiago, Chile
4 crystalline products tested head-to-head. Xypex: 10.5–11 mm water penetration. Competitors: 20.3–20.7 mm. Xypex selected as sole specified product.
Metro Línea 7 · $2.6B
Metro Línea 7
Santiago
Santiago, Chile
120-day comparative testing. Xypex improved continuously: ~10 mm at 28 days → ~3 mm at 120 days. Reconfirmed as specified product.
Xypex in Tunnel Applications

Integral Protection
for Every Tunnel Construction Method

NATM & Shotcrete
Waterproofing
Watertight shotcrete primary liner with structural fibres.
Key Benefits
  • Eliminates lining procedures and reduces schedule
  • Designed for use with shotcrete and nozzle-added accelerators
  • No risk of puncture or damage during construction
  • Permanent protection
WestConnex M4E Tunnel, Sydney — 5,578 m³ Xypex-treated shotcrete.

Thames Tideway Hammersmith Connection Tunnel — sole waterproofer, 11 weeks ahead of schedule.
Tunnel Boring
Machine (TBM)
Precast segments, station boxes, and method transitions.
Key Benefits
  • Waterproofing of precast segments, station boxes, and transitions from TBM to other methods
  • Improved durability and increased service life
  • Waterproof under positive and negative pressure
  • Self-healing of concrete cracks up to 0.5 mm
Delhi Metro DMRC Phase III & IV — precast segments, station boxes, transitions.

Tuen Mun–Chek Lap Kok Link, Hong Kong — world's largest TBM (17.6 m), avg. 50 m below sea level.
Cut &
Cover
Reduced excavation footprint and labour on site.
Key Benefits
  • Reduced excavation width by eliminating externally applied waterproofing
  • Reduced labour onsite
  • No risk of membrane puncture during construction
  • Extended service life
Tsuen Wan West Station & Tunnels, Hong Kong — 75,000 m³ Admix concrete; 56,800 m² coatings.
Immersed
Tube
Marine, submerged conditions with extreme hydrostatic pressure.
Key Benefits
  • Self-healing of cracks up to 0.5 mm
  • Increased durability and protection from harsh marine chlorides, sulphates, and aggressive groundwater
  • Waterproofs against extreme hydrostatic pressure after submersion
  • Consistent integral protection across precast elements and closure pours
Zhou Tou Ju Tunnel, Guangzhou — self-healing documented in field. Opened 2015.
Repair &
Rehabilitation
Applied from the negative side. Stops active leaks.
Key Benefits
  • Applied from the negative side
  • Stops active leaks, seals joints, extends service life
  • No extended service interruptions required
Ankara Metro (12 stations, 160,000 m²)

Istanbul Metro

Dosquebradas Tunnel
Xypex

A More Sustainable Solution

Our crystalline technology provides permanent concrete waterproofing that supports resilient infrastructure, extends service life, and enables circular construction practices.

Central to our commitment is helping projects reduce their carbon footprint while achieving their durability and sustainability objectives.

~60%
Lower Carbon
vs typical waterproofing technology
Up to187yrs
Extended Service Life
The most sustainable waterproofing is the one you never have to repeat.
Certifications
Type III EPD → 1.5 LEED pts HPD → 1 LEED pt No VOCs → LEED EQ 4.2 LCA Cradle-to-Grave ISO 9001:2015

Visual Detection System

Xypex Admix products include the proprietary Visual Detection System (VDS) tracer — invisible in natural light, visible under special light and goggles. Confirms the presence of Xypex Admix in hardened concrete, allowing independent on-site quality verification.

No other crystalline admixture offers this.

Concrete sample as seen in natural light Same concrete sample under UV light revealing Xypex VDS tracer
As seen in natural light As seen under special light and goggles
Xypex Tunnel Projects

Proven Excellence in
Global Tunnel Infrastructure

From the Washington DC Metro (1982) to today's multibillion-euro megaprojects — every construction method, every region.

Project Method Region Highlight
Hammersmith Connection Tunnel, Thames Tideway NATM / SCL United Kingdom Sole waterproofer. 120-yr design life. 11 weeks saved.
Metro Línea 7, Santiago TBM + NATM Chile 26 km, $2.6B. Confirmed via 120-day competitive testing.
Américo Vespucio Oriente II (AVO II) NATM Chile €900M. Best of 4 crystalline products tested.
Tuen Mun–Chek Lap Kok Link TBM Hong Kong World's largest TBM (17.6 m). Avg. 50 m below sea level.
WestConnex M4E Tunnel NATM Australia 5,578 m³ Xypex-treated shotcrete.
Delhi Metro DMRC Phase III & IV TBM / Cut & Cover India Precast segments, station boxes, transitions.
Tsuen Wan West Station & Tunnels Cut & Cover Hong Kong 75,000 m³ Admix concrete; 56,800 m² coatings.
Zhou Tou Ju Tunnel Immersed Tube China Self-healing documented in field. Opened 2015.
Also featured Washington DC Metro (1982), Channel Tunnel, Paris & Marseille Metro, Copenhagen Metro, Dubai Metro, Cairo Metro Line III, São Paulo Metro, Warsaw Metro, Tohoku Shinkansen, Suez Canal Road Tunnels, and 50+ additional tunnel projects worldwide.

Ready to Specify Xypex
for Your Tunnel Project?

Download the Tunnels Brochure Contact Us