A contribution to the gamma radiography of reinforced concrete structures

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:

1. 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.
2. 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.