What force must be applied for SFRM failure in the bond strength calculation?

The correct choice in this scenario is 15 pounds, which is the standard force required when calculating the bond strength for Spray-Applied Fire-Resistive Materials (SFRM). In the context of bond strength testing, this specific force is established to evaluate the adhesion properties of fireproofing materials applied to structural elements. It ensures that the materials can withstand the physical stresses they may encounter in service conditions without detaching from the substrate.

Using this standardized force allows for consistent and reliable results when assessing the performance of different SFRM products. Testing at this specific force helps to ensure that the materials meet the necessary safety and compliance standards. Understanding this benchmark is crucial for professionals in the field when selecting and applying SFRM, as it directly impacts the safety and structural integrity of buildings subjected to fire conditions.