Title: Use of Sub-Surface Radar for Structural Assessment of In-Situ Concrete

Author(s): J. H. Bungey, S. G. Millard and M. R. Shaw

Publication: Symposium Paper

Volume: 128

Issue:

Appears on pages(s): 497-514

Keywords: concretes; conductivity; dielectric constant; moisture; nondestructive tests; radar; reinforcing steels; thickness; voids; General

DOI: 10.14359/3759

Date: 11/1/1991

Abstract:
Presents the results of radar tests conducted in a controlled laboratory environment to provide an independent assessment of the usefulness of the technique for investigating in situ concrete structures. Parameters studied include size and thickness of concrete elements, the presence of voids and steel reinforcement, and the influence of moisture. The use of a commercially available computerized signal enhancement system has also been examined to assess the potential benefits. Results are presented that include typical signal response traces and show the degree of precision that can reasonably be expected from radar measurements under a range of practical circumstances. Results are considered in the light of the basic theoretical factors and a number of important limitations are identified. It is concluded that the method offers considerable potential in a range of structural applications but is subject to a number of practical limitations, and guidance is offered concerning experimental technique and interpretation of results.