What method uses polystyrene beads in SFRM testing?

The displacement method utilizes polystyrene beads in Spray-Applied Fire-Resistive Materials (SFRM) testing to assess the density and performance of the material being tested. In this method, polystyrene beads are incorporated into the testing process to create a more accurate representation of how the fireproofing material behaves under various conditions. This approach allows for the measurement of the density and effectiveness of the applied fireproofing by observing how the polystyrene beads interact with the material and its ability to displace them.

Using polystyrene beads helps simulate real-world conditions where air and other materials may influence the behavior of fireproofing materials. This method is significant in determining properties like thermal performance, structural integrity under fire conditions, and overall effectiveness for fire resistance as the polystyrene beads can indicate how the SFRM will hold up over time.

In contrast, other methods such as adhesion tests or pull-off tests primarily focus on measuring the bond strength between the SFRM and the substrate, and the spray test typically assesses the application process rather than the specific performance characteristics indicated by the use of polystyrene beads.