Abstract
A systematic presentation of arrangements and materials for detection of reinforced concrete by means of gamma-radiography is the first aim of this paper. New proposals concerning auxiliary techniques in gamma-radiography have been investigated:
-
a)
Photometric measurements on simple gamma-radiographies have been applied, in order to estimate the diameter of an embedded bar, on the basis of the difference in film density, between the image of the bar and its surrounding area.
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b)
Ordinary photogrammetric apparatuses have been used on twin stereo-radiographies for direct discrimination of complicated bars of concrete reinforcements. The same method has been applied for a direct reading of the position and diameter of every bar simultaneously, instead of repetitive application of two-equations systems for each bar in conventional stereo-radiography.
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Abbreviations
- D:
-
the film density or the distance from the source to the film
- γ:
-
the gradient of the characteristic curve of the film
- μF, μb :
-
linear attenuation coefficients of steel and concrete, respectively
- J s :
-
radiation scattered forwards
- J d :
-
radiation passing through directly
- K, λ:
-
empirical constants depending on the nature of the source and on the diameter of the field
- x :
-
the surface density of concrete
- ϕ:
-
the diameter of the bar
- b 1%,b 5% :
-
half-width of film for errors 1% and 5%, respectively
- δ:
-
transverse moving of the source
- α:
-
the distance from the source to the surface of the concrete
- α′:
-
the distance between concrete and film
- d :
-
the thickness of concrete
References
J.A. Forrester.—Gamma-radiography of concrete, Conference on Non-destructive Testing of Concrete and Timber, Institution of Civil Engineers, Great-Britain.
A. Hoenig.—Feststellung der Lage der Bewehrungin Stahlbetonkonstruktionen mit radioaktiven Isotopen, Wissenschaftliche Zeitschrift, Leipzig, 1960.
B. Proimos.—On the radiographic properties of X-rays, Athens 1965, (in greek).
Argonne National Laboratory.—Reactor Physics Constants, U.S. Atomic Energy Commission.
C. Avram andF. Gobesz.—Beiträge zur Radiographie von Stahlbetonbauteilen, Zerstörungsfreie Prüftechnik für Stahlbeton, Tagungsbericht 1969, Hochschule für Bauwesen, Leipzig.
C. Kannter.—Prüfungen au Beton mit Röntgenstrahlen, Beton u. Eisen, 11/1932.
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Tassios, T., Oeconomou, C. A contribution to the gamma radiography of reinforced concrete structures. Mat. Constr. 4, 101–106 (1971). https://doi.org/10.1007/BF02473964
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DOI: https://doi.org/10.1007/BF02473964