Due to complex material and nonuniform characteristics of reinforced concrete members, practical obstacles exist when conducting nondestructive testing for determination of the position of holes in concrete. This paper discusses how to use gamma rays to penetrate concrete and project images of internal structures and holes/discontinuities on film. By analyzing the geometry of projected images on the film, the size and position of holes in concrete members can be obtained. Referring to gamma-ray exposure curves on reinforced concrete structures, this paper also establishes a relation of gamma-ray sources and thicknesses of concrete to calculate the gamma-ray exposure time. It will help inspectors and engineers to effectively estimate the quality of reinforced concrete structures.
Chen, J., “Research and Analysis of Embankment Crack Examination and
Development of a Database,” Ph.D. dissertation, Department of Civil Engineering,
National Cheng Kung University, Tainan, Taiwan, 2005.
Chen, Y., Nondestructive Testing, Taipei, Gold-Wa, 1999.
Gin-Lon, Dan, “Detecting Infrastructures Using GPR and Tomography
Techniques,” M.S. thesis, Department of Applied Geology, National
Central University, Taiwan, 1999.
Heiskanen, K.A., H.C. Rhim and P.J.M. Monteiro, “Computer Simulations
of Limited Angle Tomography of Reinforced Concrete,” Cement and
Concrete Research, Vol. 21, Issue 4, 1991.
Htut, Trevor N.S. and Stephen J. Foster, “X-ray Imaging for the Observation
of Mode I Fracture in Fibre Reinforced Concrete,” 5th Australasian
Congress on Applied Mechanics, Australia, 1998.
Lin, C., “Digital Image Coding and Processing of GPR and Image Identification
of Research,” M.S. thesis, Department of Civil Engineering, Chung
Hua University, Hsinchu, Taiwan, 2004.
Liou, T., “The New Examine Method to Inspection of Concrete Internal
Reinforcing Bar Positions,” Ph.D. dissertation, Civil Engineering Institute,
National Chung Hsing University (NCHU), Taichung, Taiwan,
Lo, Tien-When and Philip L. Inderwiesen, “Fundamentals of Seismic
Tomography,” Geophysical Monograph Series, No. 6, 1994, pp. 1–46.
Owen, Roger Debaun, “Portable Liner Accelerators for X-ray and Electron-
Beam Applications in Civil Engineering,” NDT&E International, Vol. 31,
1998, pp. 401–409.
Pei, G., X. Hong and T. Lin, “Ground-Penetrating Radar Fault Detection
Imaging Technology and Engineering Application of Examples,” 12th
Taiwan NDT Seminar, 2004.
Peng, P.C., C.Y. Wang and C.K. Huang, “Radiographic Testing for Rebar
and Defects within Reinforced Concrete,” Journal of the Chinese Institute of
Civil and Hydraulic Engineering, Vol. 19, No. 3, 2007.
Peng, P.C., C.Y. Wang, C.K. Huang and M.C. Chen, “Detecting Steel Bars
and Defects in Reinforced Concrete Members Using Gamma Rays,” Materials
Evaluation, Vol. 66, 2008, pp. 150–154.
Shu, S., “The Highway Bridge Protects and Maintains,” Taichung, Taiwan,
Youth Cultural Establishment Company, 1996.
Stein, M., V.A. Kasyanov, V.L. Chakhlov, J. Marjoribanks and S.
Hubbard, “Small-Size Betatrons for Radiographic Inspection,” 16th
Su, Z., “The Ultrasonic Examination Applies Research in the Reinforced
Concrete Structure Interior Image,” M.S. thesis, Earth and Environmental
Sciences, Institute of Applied Geophysics, and Environmental Sciences,
Institute of Seismology, National Chung Cheng University, Chiayi,
Tillack, G.R., C. Nockemann and C. Bellon, “X-ray Modeling for Industrial
Applications,” NDT&E International, Vol. 33, No. 6, 2000, pp. 481–488.
Yang, C., “Deal with Reinforced Concrete Structures of CT Imaging,” M.S.
thesis, Department of Civil Engineering, National Central University,
Taoyuan, Taiwan, 2003.