Passive Fire Protection Flashcards
7 cards from real CFPS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Passive Fire Protection flashcards as text
Spray-applied fire-resistive material (SFRM) provides fire protection to structural steel primarily by:
Answer: Insulating the steel from heat, slowing its temperature rise and delaying loss of structural capacity
SFRM is a low-density insulating material that slows heat transfer to the steel, extending the time before the steel reaches its critical temperature and loses load-bearing capacity.
In structural fire protection, the W/D ratio for a steel member represents:
Answer: The ratio of the weight per linear foot of the member to its heated perimeter, used to calculate required SFRM thickness
W/D (weight-to-heated-perimeter ratio) is a thermal property used in SFRM design: higher W/D sections heat more slowly and require less insulation thickness.
The 'critical temperature' for structural steel in performance-based fire engineering is most commonly defined as:
Answer: The temperature at which steel retains approximately 60% of its ambient yield strength, approximately 1000°F (538°C)
The critical temperature for steel is typically taken as 538°C (1000°F), the point at which it retains about 60% of its room-temperature yield strength, representing a threshold for structural instability.
How does an intumescent coating for structural steel differ functionally from SFRM?
Answer: Intumescent coatings provide no protection until activated by heat, at which point they expand to form a thick insulating char layer
Intumescent coatings appear thin at ambient conditions but expand dramatically when exposed to heat, forming an insulating char foam that shields the steel, unlike the pre-applied bulk of SFRM.
In fire-resistance testing per ASTM E119, the 'restrained' condition for a floor-ceiling assembly refers to:
Answer: The assembly's thermal expansion being resisted by surrounding structure, which generally increases measured fire resistance
A restrained assembly has its thermal expansion resisted by the surrounding structure; this typically develops compressive arching forces that can significantly enhance fire-resistance compared to the unrestrained condition.
A fire-resistive joint system (linear gap seal) is specifically designed to:
Answer: Seal the gap between curtain wall assemblies and floor slabs to prevent passage of flame and hot gases between floors
Linear gap seals (tested per ASTM E1966/UL 2079) protect the perimeter gap between the slab edge and curtain wall, a common pathway for vertical flame spread in multi-story buildings.
Which test standard evaluates the fire resistance of curtain wall/floor slab perimeter joints (linear gap seals)?
Answer: ASTM E1966 / UL 2079
ASTM E1966 and UL 2079 are the test standards for fire-resistive joint systems, including the curtain wall perimeter gap and other linear joints in fire-rated construction.