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Innovation In Structural Investigation

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Materials Testing and Structural Investigations

Visual Survey of Fire Damaged Structures

Classification of Fire Damage in Reinforced Concrete Structures

Class of Damage Element Condition of plaster/finish Colour Crazing Spalling Exposure and condition of main reinforcement* Cracks Deflection/Distortion
0 Any Unaffected or beyond extent of fire
1 Column some peeling normal slight minor none exposed none none
Wall some peeling normal slight Any none exposed none none
Floor some peeling normal slight Any none exposed none none
Beam some peeling normal slight Any very minor exposure none none
2 Column substantial loss pink ** moderate localised to corners up to 25% exposed, none buckled none none
Wall substantial loss pink ** moderate localised to patches up to 10% exposed, all adhering none none
Floor substantial loss pink ** moderate localised to patches up to 10% exposed, all adhering none none
Beam substantial loss pink ** moderate localised to corners, minor to soffit up to 25% exposed, none buckled none none
3 Column total loss whitish grey extensive considerable to corners up to 50% exposed, not more than one bar buckled minor none
Wall total loss whitish grey extensive considerable to surface up to 20% exposed, generally adhering small not significant
Floor total loss whitish grey extensive considerable to soffit up to 20% exposed, generally adhering small not significant
Beam total loss whitish grey extensive considerable to corners, sides, soffit up to 50% exposed, not more than one bar buckled small not significant
4 Column destroyed buff surface lost almost all surface spalled over 50% exposed, more than one bar buckled major any distortion
Wall destroyed buff surface lost almost all surface spalled over 20% exposed, much separated from concrete severe and significant severe and significant
Floor destroyed buff surface lost almost all surface spalled over 20% exposed, much separated from concrete severe and significant severe and significant
Beam destroyed buff surface lost almost all surface spalled over 50% exposed, more than one bar buckled severe and significant severe and significant

Table 1 Fire damage assessment

Notes:
* In the case of beams and columns the main reinforcement shall be assumed to be in the corners only unless other information exists.

** Pink discolouration due to ferric salts in aggregates. Not always present and seldom in calcareous aggregate.

The following action(s) will be required for the repair of members classified as above

Class of Damage Repair Classification Repair Requirements
Class 0 Decoration Redecoration if required.
Class 1 Superficial Superficial repair of slight damage not needing fabric reinforcement.
Class 2 General Repair Non-structural or minor structural repair restoring cover to reinforcement where this has been partly lost. The gunite or repair material reinforced with a nominal light fabric.
Class 3 Principal Repair Strengthening repair reinforced in accordance with the load-carrying requirement of the member. Concrete and reinforcement strength may be significantly reduced requiring check by design procedure.
Class 4 Major Repair Major strengthening repair with original concrete and reinforcement written down to zero strength, or demolition and recasting.

Reproduced from Concrete Society Technical Report No. 33 "Assessment and Repair of Fire-damaged Concrete Structures" (1990)

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