Citation

Khoury GA, Sullivan PJE. Fire Safety J. 1988; 13(1): 69-72.

Copyright

(Copyright © 1988, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Long-standing research at Imperial College into the effect of elevated temperatures on concrete for fire and nuclear reactor applications has recently been intensified. A wide range from the thermally unstable gravel aggregate concrete to the thermally more stable lightweight included mechanical properties, microstructural analysis and conditions within the test specimen.The transient thermal strain of concrete during first-time heating under load to 600 [deg]C can be described by two main components, the free thermal strain (FTS) and the load-induced thermal strain (LITS), which possess distinct and different properties but which were not significantly influenced by the age at testing. A 'master' LITS curve for concrete was found to exist for temperatures up to about 450 [deg]C.Basic creep studies at constant temperatures indicated a marked increase in creep above 550-600 [deg]C for cement paste and lightweight concrete which suggests that the structural, though not necessarily the refractory, usefulness of Portland cement-based concretes in general is limited to temperatures below 550-600 [deg]C.Initial studies of the effect of heating on the strength of concrete show certain trends which may differ from those expected from current knowledge. This suggests that it may be possible to design concretes in the future which retain a larger proportion of their initial strength after heating than is achieved at present.