Design Process

摘要

Following the Cardington tests, a number of simple structural models were developed which combine the residual strength of steel composite beams with the strength of the slab in fire. These models use the combined yield line and membrane action approach described in BRE Digest 462 to assess performance of a slab designed to generate tensile membrane action. Using these models, the designer is able to leave large numbers of secondary beams unprotected in buildings requiring 30 to 120 minutes fire resistance although some compensating features, such as increased mesh size and density, may be required.