Building Fire Safety, Structural Fire Tests, and Performance Based Codes

Abstract

Building fire safety is a general term covering life safety of occupants and fire resistance of buildings. The former deals with emergency exits, escape signs, detecting system, alarms, sprinklers, smoke control, and fire extinguishers. The later involves with construction materials, architectural design to prevent fire spread, and theoretical analysis as well as experimental study to maximize structural performance in fire. Among them the experimental study, particularly structural fire tests, has attracted serious attentions from international engineering societies. The first ISO TC-92 meeting held in London, 1961 entitled, “Fire Tests on Building Materials and Structures” set a landmark of fire resistance research. Since then, innovative technologies on building materials, engineering analyses, structural designs, and fire tests have been developed to generate fire ratings of steel and concrete elements. Of these developments, an element fire test is the most expensive attributed to a need a large furnace equipped with sophisticated hydraulic system, temperature control and data acquisition units. The obtained data have been widely used by engineers, insurers, and building officials in assessing fire safety of buildings. Fire tests of full sized concrete beams, slabs, and columns in North America were carried out in accordance with the ASTM E-119 standard procedure or ISO 834. One of the standard’s weaknesses involves with a provision allowing the supported regions of a specimen be protected from fire exposures. The fire endurance of a structural element tested without exposing its end points to fire conceivably differs from that of a correspondent member of an actual building in fire. An idea to include structural joints in a fire test surfaced 4 decades ago but did not receive public attention until PBC was introduced in early 1980’s. The uniqueness of PBC includes design flexibility and requiring verification tests of frame structures. The 911 WTC disaster investigation conducted by National Institute of Standards and Technology (NIST) supports PBC requirements on frame fire tests.