Basic approach for the diagnosis of concrete after fire...
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Concrete structures don’t necessarily collapse during a fire. It is of economical interest to reuse the structure after appropriate repair. A scientific and systematic methodology to assess the damage and to estimate the residual strength is of great importance. Concrete changes physically when heated: crack development and colour change. Quantification of these alterations supplies the needed information to assess the temperature and the residual strength. TC and SCC are two types of concrete; SCC has higher flow ability which results in a larger potential for practical applications. Colour change Crack development Strength degradation Cracks in cementmatrix and interfacial zone Effect of storage after fire (Recuring) ASSESSMENT OF RESIDUAL STRENGTH Basic approach for the diagnosis of concrete after fire exposure E. Annerel, L. Taerwe and P. Vandevelde Magnel Laboratory for Concrete Research Department of Structural Engineering, Faculty of Engineering, Ghent University Technologiepark-Zwijnaarde 904, 9052 Gent http://www.LaboMagnel.UGent.be Ir. Arch. Emmanuel Annerel PhD Student T: +32 (0) 9 264 55 19 ; F: +32 (0) 9 264 58 45 [email protected] The authors would like to thank the Fund for Scientific Research in Flanders (FWO) for the financial support . . CONCLUSIONS 1. Measurements of colour and porosity are good indicators for assessing the residual strength of concrete after fire exposure. An elliptical path in the a*b*- colour space can be noticed. In this colour space: a* ~ red and b* ~ yellow. 2. A strength recovery is noticeable after a further degradation of 7-28 days, but is still lower than the strength directly after cooling down (0 days after fire) to ambient temperature. 3. There are two types of cracks: interfacial and matrix cracks. They have the same contribution to the increase of the total porosity.
Transcript of Basic approach for the diagnosis of concrete after fire...
Concrete structures don’t necessarily collapse duri ng a fire.
It is of economical interest to reuse the structure after appropriate repair.
A scientific and systematic methodology to assess t he damage and to estimate the residual strength is o f great importance.
Concrete changes physically when heated: crack deve lopment and colour change.
Quantification of these alterations supplies the ne eded information to assess the temperature and the residual strength.
TC and SCC are two types of concrete; SCC has highe r flow ability which results in a larger potential for practical applications.
Colour change Crack developmentStrength degradation
Cracks in cementmatrix and interfacial zone
Effect of storage after fire (Recuring)
ASSESSMENT OF RESIDUAL STRENGTH
Basic approach for the diagnosis of concrete after fire exposure
E. Annerel, L. Taerwe and P. Vandevelde
Magnel Laboratory for Concrete ResearchDepartment of Structural Engineering, Faculty of En gineering, Ghent University
Technologiepark-Zwijnaarde 904, 9052 Gent
http://www.LaboMagnel.UGent.be
Ir. Arch. Emmanuel AnnerelPhD Student
T: +32 (0) 9 264 55 19 ; F: +32 (0) 9 264 58 45
The authors would like to thank the Fund for Scientific Researchin Flanders (FWO) for the financial support..
CONCLUSIONS
1. Measurements of colour and porosity are good indica tors for assessing the residual strength of concrete after fire exposure. An elliptical path in the a*b*-colour space can be noticed. In this colour space: a* ~ red and b* ~ yellow.
2. A strength recovery is noticeable after a further d egradation of 7-28 days, but is still lower than the strength directly after coolin g down (0 days after fire) to ambient temperature.
3. There are two types of cracks: interfacial and matr ix cracks. They have the same contribution to the increase of the total porosity.
