Watertight Expansion Joints and Construction Sealants by EMSEAL

Emshield® TFR-RWS

RWS Compliant, Fire-Rated, Tunnel Expansion Joint

A fire-rated tunnel expansion joint, TFR-RWS is Sika Emseal’s Emshield material confirmed by testing, and additionally affirmed by engineering judgement to meet the requirements of specific tunnel fire rating scenarios including RWS.

Fire-retardant-impregnated foam is coated with a high grade sealant coating. The resulting composite is then factory compressed to less than its nominal size for installation into the joint gap. The system is installed into epoxy adhesive field-applied to the sides of the joint face and tunnel-lining fireproofing materials. A sealant band of supplied caulking fills voids in the substrate to bellows interface and completes the system. The tunnel-facing surface of the TFR-RWS is durable and resistant to typical tunnel-lining cleaning procedures.

What is RWS Tunnel Fire Rating?

RWS (Rijkswaterstaat) is a tunnel fire standard created as a result of testing done in 1979 by the Rijkswaterstaat (Ministry of Infrastructure and the Environment) in The Netherlands. It is based on a worst case scenario of 1765 ft3 (50 m3) of fuel (a tanker load) being ignited in the relatively small confines of a tunnel.

The resulting heat load was found to be approximately 300MW, with temperatures reaching 2012oF (1100oC) after only 5 minutes, peaking at 2462oF (13500C) with a fire burn duration of 2 hours. It is known that spalling of the concrete tunnel structure when surface temperatures reach approximately 716oF (380oC). Spalling is very detrimental to the structural integrity of the entire tunnel, and if unchecked, may result in a complete tunnel collapse. Significant spalling may require costly remediation post-fire to restore structural integrity even if the tunnel isn’t collapsed. Life safety is a serious concern. The Mont Blanc tunnel fire in Europe killed 39. The Caldecott tunnel Fire in California killed seven people.

Concrete additives or fire resistive concrete coating or barrier products meeting the RWS standard are able to keep the concrete surface below 716oF (380oC) for the entire two hour duration of the RWS fire curve.

When a fuel tanker explodes in a tunnel there is a massive fire ball. The flame and heat almost instantly hits the tunnel ceiling. Concrete that is not treated or coated with a fire resistive material can spall in massive chunks compromising structural integrity. Coatings, like RWS-tested spray applied fire resistive material (SFRM) or fire resistive board can be used on the faces of concrete to meeting the RWS criteria.

But what if there is a gap in the fireproof coating?

Structural joints to accommodate seismic, thermal, concrete shrinkage and other movements are literally a gap through the fireproofing. Emshield TFR-RWS fills this gap, handles the movement, and restores the RWS fire rating to the tunnel lining.

By Finite Element Analysis (FEA) and engineering judgement for the Calgary Trail Airport Tunnel project in Alberta, Canada, Emshield has been shown to be able to handle the RWS time/temperature curve.

Additionally, by full-scale testing, TFR-RWS was proved to be capable of resisting a modified RWS time-temperature curve required for sealing the Alaskan Way Viaduct SR-99 Tunnel project in Seattle, WA.

Contact us for your specific tunnel fire proofing requirements.

Emshield® TFR-RWS

RWS Compliant, Fire-Rated, Tunnel Expansion Joint


1/2″ to 4″ (12mm – 100mm)

Depth of Seal: 4-inches (100mm)


100% Total (+50% and -50% of nominal supplied size)


Standard color is grey.  Can also be made in black and other colors on request (consult Sika Emseal).


For tunnel roofs and walls
• Structural, control, and seismic joints
• Meets RWS (Rijkswaterstaat) time/temperature curve
• FEA proven to handle worst case fuel tanker fire in tunnel
(2-Hour, 300MW fire load, max. temperature 2,462°F (1,350°C))
• Used in conjunction with spray-applied fire resistant materials
• Non-invasive anchoring; no mechanical fasteners
• Pre-compressed, self expanding, never in tension
• For curves, straight runs and 90-degree or other angle corners
• Handles variations in joint size through size-switching

U.S. Patents

10,316,661 B1
8,739,495 C1

(US Patent 9,200,437; 9,637,915)

  • Universal-90’s (or U-90’s) are factory-made 90-degree transition pieces that ensure continuity-of-seal and fire protection where expansion joints change plane.
  • Use of U-90’s eliminates the field work needed to make plane changes making overall installation fast and efficient.
  • Watertightness through the plane change is guaranteed–leaving nothing to chance in field-fabricating inside and outside transitions.
  • U-90 transitions are symmetrically coated on both faces allowing them to be installed as an inside corner or as an outside corner.
  • Straight-run sticks are joined in the field to the U-90’s.
  • U-90’s have a 12-inch (305mm) long leg and a 6-inch (152mm) vertical piece on each side of the elbow.

(US Patent 10,570,611)

  • Custom-90’s are available when field conditions and measurements are known up front.
  • Custom-90’s are used in applications where numerous inside and outside 90-degree transitions are required. Consult Sika Emseal.
Supplied LengthProduct CodeNominal Material size (=Joint Size at Mean T)Depth of Seal
6.56 LF (2M)StickTFR-0050-RWS1/2″(12mm)4″ (100mm)
TFR-0125-RWS1 1/4″(30mm)
TFR-0150-RWS1 1/2″(40mm)
TFR-0175-RWS1 3/4″(45mm)
TFR-0225-RWS2 1/4″(55mm)
TFR-0250-RWS2 1/2″(60mm)
TFR-0275-RWS2 3/4″(70mm)
TFR-0325-RWS3 1/4″(80mm)
TFR-0350-RWS3 1/2″(90mm)
TFR-0375-RWS3 3/4″(95mm)