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In some cases, it is necessary to evaluate and document structures which were subjected to fires during construction. Due to the lack of official regulations on the subject, the analyses and documentation on these incidences, when reported to the regulatory authorities, implied unconventional activities, both for the utility and the A/E. The paper describes several fires affecting nuclear power plant concrete structures. They were all caused by inadvertent human actions. The presence of highly combustible auxiliary cons-truction materials contributed to their propagation. It is recommended that the cost (purchase and installation) of these auxiliary materials be evaluated against the use of alter nate (noncombustible)ones before making any decision, sufficiently in advance to avoid costly and time-consuming changes that may affect a usually tight schedule. As a result of visual inspection, followed by "in situ" and laboratory tests and engineering analyses of the affected elements, some elements had to be demolished and reconstructed while others were found to be acceptable.

A major three span highway bridge in Southern Ontario was 1nvYived in a construction fire while it was being widened 25 years ago. Concrete, ranging in age from 6 days to 20 years, in an abutment, the adjacent arch rings and spandrel columns was severely damaged. The structure is now revisited to assess the long term performance of the remedial works and to consider whether the investigation and repairs might have taken a different course if today's testing, analytical and repair techniques had been available then. The strengthening of the damaged arch springings and the shotcrete restored concrete sections exposed to a harsh environment have stood the test of time. The review of investigative and repair methods identifies advances made in recent years, and justifies long term confidence in o'lder procedures which are still in use.

The purpose of this paper is to outline some of the proposed changes to the Concrete Society Technical Report 15 which is the most comprehensive UK document dealing with assessment and repair of fire-damaged concrete structures. The publication is being updated to take into account changes of practice and methods of assessment since 1978. Repair techniques other than Gunite are to be included with particular comment in respect to resin repairs.

Evaluation of fire-damaged concrete has been made using field-applicable test techniques which are valuable but limited. With the advent of reliable non-destructive testing methods, a much more comprehensive assessment of damage is available. The objective of this paper is to present. information on Pulse-Echo, magnetic and microwave testing techniques. Pulse-Echo non-destructive testing can be conducted on insitu concrete for: measuring thickness of damaged concrete assessing bond loss between concrete and reinforcing steel detecting internal cracks and their orientation determining degree and extent of cement matrix microcracking estimating insitu concrete compressive strength Accompanying the Pulse-Echo method are steel reinforcement location techniques that involve microwave and magnetic principles. These tests can determine remaining concrete cover and additional data for engineering the required repairs. Of equal importance to the assessment of damage is the evaluation of the performed repairs to determine that the repairs satisfy all the structural requirements of the original specifications.

Experiments were carried out ith measurements of the total defo ission in order to investigate the evelopment and deformation behavio y temperature conditions.S purpose specimens were loaded wi th different stress le- on normal concrete specirmation and of the acou-correlation between ur of concrete during vels and heated up to maximum temperatures between 150 "C and 750 OC. After a holding period the specimens were cooled under load. The creep deformations showed strongly increasing rates at about 450 OC during heating and at the beginning of the cooling phase. , In the heating phase the activity of acoustic emissions increased considerably. During the holding period no remarkable activity e observed. A new increase of the acoustic activity could rly observed at the beginning of the cooling phase. rmal concrete specimen, the main a.ctivity in the damaging occurs during unsteady temperature conditions, and is nt on the maximum temperature reac hed. parison between acoustic emission activity and creep de-formations shows that the acoustic emission activities are high at e time that creep deformations areI high.