Fire resistance of concrete walls with light aggregate

Purpose – The purpose of this paper is to present the design methods for fire-exposed concrete columns and walls. In addition, it presents analyses and tests showing that the methods are applicable for designing columns and walls of lightweight aggregate concrete based on expanded clay aggregate as well as heavy normal weight concrete and that the methods fit smoothly with cold design, when the fire exposure varies towards no fire.

Design/methodology/approach – During the 1990s, some of these design methods were included in the Eurocode as “the zone method”. They are still a part of the code. The rest of the methods, which were not included, served in practice, teaching and research. The present paper derives calculation methods proving their connection with common design for load cases without fire exposure.

Furthermore, the paper presents full-scale tests proving the validation of the design methods for structural members of light aggregate concrete in addition to the full-scale tests of heavy concrete members. Findings – The design methods give correct estimates of the load-bearing capacity of eccentric loaded concrete columns.

An extended version of the methods estimates load-bearing capacity for walls with fire exposure on one side with sufficient accuracy for the purpose of design. Originality/value – The author developed the main parts of the design methods in the 1980s and 1990s and others have from time to time referred to some parts of them mainly the minor parts published in the Eurocodes.

However, owing to work overload, the author has not published the derivation and verification of them before. This paper provides in particular a verification against full-scale tests of light-aggregate concrete walls not published before.