Ardex RA 54 Joint Sealant

For industrial concrete floors subject to heavy-duty vehicle traffic, ARDEX RA 54 fills interior control joints and new construction saw joints to support heavy wheels and prevent joint edge spalling. This fast-setting, semi-rigid polyurea formulation cures rapidly, allowing repaired joints to be shaved in 45 minutes and opened to full traffic in 90 minutes at 23°C.

What it does

ARDEX RA 54 is a semi-rigid joint sealant designed to protect concrete joint edges from chipping under the impact of heavy warehouse and industrial traffic. With a Shore A hardness of 75 to 80, it provides the necessary rigidity to support wheel loads across the joint while maintaining 10% to 12% joint movement to accommodate minor thermal cycling. The material feeds by gravity into prepared joints, can be overfilled, and is shaved flush with the floor surface using a sharp floor scraper after curing.

Numbers that matter

• 90-minute cure time: Rapid return-to-service window at 24°C, minimizing facility downtime by allowing vehicle traffic shortly after application.
• 75 - 80 Shore A hardness: High semi-rigid support to reinforce concrete joint shoulders against heavy-duty wheel loads.
• 8.3 MPa tensile strength: High cohesive strength to maintain joint integrity under stress.
• 45-minute shave window (at 23°C): Practical timing for installers to scrape excess overfilled material flush with the concrete surface. This window varies by temperature: 20 minutes at 38°C to 49°C, 45 minutes at 21°C to 27°C, and up to 2 hours at 10°C to 15°C.
• 0 g/L VOC: Clean formulation suitable for interior industrial installations without solvent emissions.

Where to use it

Suitable for horizontal concrete surfaces, including interior control joints, new construction saw joints, and cured cracks. It can be used in exterior applications only when joint movement from thermal cycling remains minimal (10% to 12%). For heavy-duty traffic areas, joint width must be a maximum of 19mm with a minimum depth of three times the width, or 60mm. For light foot traffic, the joint width must be a maximum of 19mm with a minimum depth of 13mm.

Limitations

• Do not use in expansion joints; ARDEX RA 54 is not designed for joints subject to high movement.
• Highly sensitive to moisture during application and cure. Do not apply if any dampness or moisture is present in the substrate or environment.
• New concrete must be fully cured for a minimum of 28 days to release moisture before application.
• In exterior applications, the grey material will initially change colour to grey-green before returning to grey after 90 days.
• Do not attempt to force adhesive out of a hardened mixing nozzle; always use a new nozzle with each new cartridge to avoid cartridge rupture or improper mixing.

How to apply

Ensure the concrete bonding surfaces are clean, sound, and dry. Old concrete must be profiled or mechanically roughened with a wire brush or sandpaper, while new concrete must be at least 28 days old. Cut along cracks using a saw or grinder with a dry diamond or abrasive blade to create a clean 90° angle, preventing feathered edges. Blow out all dust and debris from the joint.

Insert a backer rod or clean kiln-dried sand into the bottom of the joint prior to dispensing. This prevents three-sided adhesion (bonding to the bottom), which causes sealant failure during joint expansion and contraction. Dispense the polyurea using steady, full trigger pulls to gravity-feed the joint, slightly overfilling if the joint is to be shaved flush.

Topcoat compatibility

If applying a topcoat over ARDEX RA 54, wait 24 hours after application before applying a primer. A premium primer must be applied before any topcoat is laid down. Always install a small test area of the primer and topcoat system and observe it for 7 days to verify adhesion and compatibility before proceeding with the full application.