Practical operation of data-logging covermeters and the interpretation of results

Author(s): J.F. Fletcher, C.I. Woolhouse
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 260- 261
Total Pages: 2
Language: English

Covermeters are widely used for the non-destructive testing of concrete structures to determine if reinforcement bars are adequately covered with concrete and to determine the location of safe spots for drilling, for strengthening, for repair work and for refurbishing the structure.
The use of Covermeters and the requirements of their accuracy for use are described in BS 1881 Part 204. Reinforcement bars can be detected using a pulsed electromagnetic field generated by a coil. Secondary search coils detect the resulting eddy currents induced in the bars and the location, orientation, depth (concrete cover) and diameter of the bars can be determined from this return signal.
Developments in Covermeter design has resulted in the addition of data-logging features as a key aspect of portable Covermeters with software that provides support for the analysis and presentation of data sets generated as a result of surveys carried out on site.
Covermeters now make use of intelligent sensor technology to allow a range of interchangeable sensors to be used with a single Covermeter, including borehole sensors for finding pre-stressing or posttensioning tendons deep within the reinforcement structure, sensors for the detection and measurement of stainless steel reinforcement and Half Cell for the assessment of corrosion conditions.
Consisting of either a copper electrode in a copper sulphate solution (Cu/CuSO4) or a silver electrode in a silver chloride solution (Ag/AgCl), each Half-Cell is a sealed unit making site surveys easy to perform.
This paper describes the use and capabilities of such a combined Covermeter and Half-Cell unit. Field data from a survey carried out in the UK will be presented to show the analytical capability of the system. The interpretation and presentation of the data will be discussed.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00