Unraveling the temperature distribution in fire-damaged concrete by means of PFM microscopy: Outline of the approach and review of potentially useful reactions
article
Concrete is a poor conductor of heat. Nevertheless, heating of concrete results in physico-chemical conditions shifting in or out the thermodynamic stability field of specific phases (minerals) in the concrete, effectuating their (dis)appearance. Metamorphic petrology is a branch of geology that deals with the study of such changes; as a basic approach to unravel the heating history of rocks, domains with phases (minerals) specific for a set of discrete physico-chemical conditions are delineated (mapped). Unravelling the heating history of concrete is important to forensic research or to determine whether a concrete structure subjected to fire and its components are still structurally sound. Analogous to metamorphic petrology, thermally triggered reactions in concrete result in changes in specific phases which may be used to trace isograds. In the case of heated concrete, these occur in response to temperature alone, and may hence be used to trace temperature variations in concrete with depth (isograds). The method involves a combination of visual inspection and the use of microscopic methods in a systematic way to study the thermally affected concrete. It is a powerful diagnostic tool that has successfully been applied in research and testing of concrete linings in tunnels, assessment of fire-damage to structures and evaluation of fireproofing in waste incinerators
TNO Identifier
330246
Source
Heron, 46(4), pp. 253-264.
Pages
253-264