Adhesion Testing of Rapid Set Membranes

Adhesion of Tufflon, Elaston, Hybron, Polytuff and Colourtuff Range

The rapid-curing protective membranes based on polyurea, polyurethane or a blend (Hybrid) exhibit excellent adhesion to steel and concrete. Understanding the parameters for testing adhesion and the time restraints required for full adhesion is essential.

Rapid-set membranes gel within 5 to 30 seconds can be walked on after 5 to 30  minutes and returned to service generally within 24 hours. Understanding that full physical properties may take up to 14 days to develop is essential.

Adhesion testing should be performed with a hydraulic adhesion testing device. A 50mm dolly should be used for concrete, and a 20mm dolly for steel applications. This test should be left until the polyurea has been cured for seven days. However, this is only sometimes possible. It is crucial, therefore, to leave it at least two days. A minimum of 1.5MPa is necessary on both concrete and steel.

However, if left for the entire development period of 7 to 14 days, a much higher result (up to 3.5MPa in concrete and even higher on steel) will often be achieved.

Pulling by hand on the cured polyurea to test for adhesion is not recommended, as until the product has cured for 14 days this will usually result in the polyurea being pulled away from the substrate or primer. The force placed on the polyurea by pulling is not comparable to the force using a hydraulic testing device and, therefore, is not a reliable indicator of adhesion.

TYPICAL CURING SCHEDULE RAPID MEMBRANES
Gel time
5 to 30 seconds
Tack-free time
30 to 60 seconds
Walked on (carefully)
5 to 30 minutes
Normal Return to service
24 Hours
Full immersion in water
7 Days
Full physical properties
7 to 14 days
If you have any other issues, please feel free to contact our technical office at 1300 123 085 and speak to either Bryant or Ben.