Digital fast neutron radiography of steel reinforcing bar in concrete

Mitton, K. and Jones, A. and Joyce, M.J. (2014) Digital fast neutron radiography of steel reinforcing bar in concrete. Journal of Instrumentation, 9. ISSN 1748-0221

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Abstract

Neutron imaging has previously been used in order to test for cracks, degradation and water content in concrete. However, these techniques often fall short of alternative non-destructive testing methods, such as γ-ray and X-ray imaging, particularly in terms of resolution. Further, thermal neutron techniques can be compromised by the significant expense associated with thermal neutron sources of sufficient intensity to yield satisfactory results that can often precipitate the need for a reactor. Such embodiments are clearly not portable in the context of the needs of field applications. This paper summarises the results of a study to investigate the potential for transmission radiography based on fast neutrons. The objective of this study was to determine whether the presence of heterogeneities in concrete, such as reinforcement structures, could be identified on the basis of variation in transmitted fast-neutron flux. Monte-Carlo simulations have been performed and the results from these are compared to those arising from practical tests using a 252Cf source. The experimental data have been acquired using a digital pulse-shape discrimination system that enables fast neutron transmission to be studied across an array of liquid scintillators placed in close proximity to samples under test, and read out in real time. Whilst this study does not yield sufficient spatial resolution, a comparison of overall flux ratios does provide a basis for the discrimination between samples with contrasting rebar content. This approach offers the potential for non-destructive testing that gives less dose, better transportability and better accessibility than competing approaches. It is also suitable for thick samples where γ-ray and X-ray methods can be limited.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Instrumentation
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/2600/2610
Subjects:
ID Code:
132332
Deposited By:
Deposited On:
01 Apr 2019 16:00
Refereed?:
Yes
Published?:
Published
Last Modified:
16 Nov 2020 08:58