This paper shows how temperature and rate of burning data from an
international programme of experiments on the behaviour of fully developed fires
in compartments can be used to calculate, for each fire, the thermal properties
of a protected steel column which just attains a critical temperature. It
demonstrates how the time tf for the same column to reach this temperature in
the standard fire resistance test can be calculated. A correlation is then
obtained for a range of scales, shapes, fire loads, ventilation areas and fuel
thicknesses in the form tf = K(L/?(AWAT)) where L, AW, AT denote respectively
fire load, window area and the sum of wall and ceiling area. The value of K
varies slightly with fuel spacing. Data from other experimental fires in
larger scale brick and concrete compartments, including those by Odeen with
forced ventilation, have been examined and give a somewhat lower value of K.
Reasons for this are discussed. The calculations are compared with those of
Kawagoe and Sekine, Lie, Pettersson and Odeen, and the relation to Ingberg's
early experiments is examined.
