Fireproof sealant for bridge arch cavities

Fireproof sealants and cavity barriers designed for structural applications can provide up to 120 minutes of fire resistance for bridge arch cavities, with options including intumescent sealants, acrylic fire caulks, and polymer-based wet-zone sealants.

Recommended Fireproof Sealant Types

1. Intumescent Sealants and Cavity Barriers Intumescent materials expand when exposed to heat, effectively sealing gaps and preventing fire spread. Products like PFC Corofil cavity barriers are designed for cavities up to 600mm and provide up to 120 minutes of fire resistance, suitable for ventilated and non-ventilated bridge arch cavities. They are available in strips or blocks and can be customized to fit specific cavity dimensions, ensuring robust fire protection . 2. Polymer-Based Wet-Zone Sealants For bridge arches exposed to moisture or weathering, Siderise FR-X Fire Rated Wet Zone Sealant offers up to 4 hours of fire resistance. It is certified under EN 1366-3 and EN 1366-4 and provides flexibility, durability, and acoustic sealing performance, making it ideal for external structural cavities . 3. Acrylic Firestop Sealants Universal fire caulks like Hilti CP 606 provide flexible firestop sealing for joints and penetrations. These sealants are suitable for linear gaps and can be applied in bridge arch cavities where movement or vibration may occur. They are tested for fire-rated joints and through penetrations, ensuring compliance with safety standards . 4. Spray-Applied and Rigid Board Fireproofing For larger structural cavities, Isolatek CAFCO® and FENDOLITE® products offer spray-applied or rigid board fireproofing solutions. These materials are UL-certified and can be applied to steel or concrete bridge arches, providing a continuous fire-resistant layer that meets commercial and infrastructure standards .

Key Considerations for Bridge Applications

• Fire Rating: Ensure the sealant or barrier meets the required fire resistance period (e.g., 60–120 minutes) for bridge safety codes.
• Environmental Exposure: Choose wet-zone or weather-resistant sealants for outdoor bridge arches.
• Installation: Precut blocks or ready-to-install noggins reduce labor and ensure consistent fire protection.
• Compliance: Verify UL, EN, ASTM, or local standards certification for structural fire protection .
• Maintenance: Inspect periodically for cracks or degradation, especially in high-moisture or high-vibration areas.

Conclusion

For bridge arch cavities, intumescent cavity barriers, polymer-based wet-zone sealants, and acrylic fire caulks are all viable options depending on environmental exposure and fire rating requirements. Products from PFC Corofil, Siderise, Hilti, Sika, and Isolatek provide tested and certified solutions that ensure fire safety, structural integrity, and compliance with international standards .