Dielectric measurement method for real-time monitoring of initial hardening of backfill materials used for underground construction. (30th March 2016)

• Record Type: Journal Article
• Authors: Karlovšek, Jurij; Schwing, Moritz; Chen, Zhen; Wagner, Norman; Williams, David J; Scheuermann, Alexander
• Is Part Of: Journal of geophysics and engineering. Volume 13:Number 2(2016:Apr.)
• Page Start: S19
• Page End: S27
• Publication Date: 2016-03-30
• Subjects: dielectric relaxation spectroscopy -- ground penetrating radar velocity and attenuation -- one- and two-component grout -- non-destructive testing -- open-ended coaxial probe -- real-time monitoring; Geophysics -- Periodicals; Prospecting -- Geophysical methods -- Periodicals; Engineering -- Periodicals; 622.1505
• DOI: 10.1088/1742-2132/13/2/S19
• Languages: English
• ISSNs: 1742-2132

Abstract

Abstract: The broadband dielectric measurement method based on the vector network analysis technique, in combination with an open-ended coaxial probe, was applied to the determination of the dielectric relaxation behaviour of one- and two-component backfilling grout materials in the frequency range from 40 MHz to 2 GHz. The cement hydration process and the gelling of commercial grouts was monitored in real-time to investigate the application of non-destructive testing methods in the tunnelling industry. It was found that the time-dependent dielectric relaxation behaviour can accurately reveal the different stages of the hydration process and delineate the start of gel hardening. These measurement results demonstrate the practicability of the real-time dielectric measurement method to determine the broadband dielectric parameters of conventional backfill materials used in underground construction to determine construction integrity using non-destructive testing methods.