Document Type

Working Paper

Rights

This item is available under a Creative Commons License for non-commercial use only

Abstract

The performance of the surface zone of concrete is acknowledged as a major factor governing
the rate of deterioration of reinforced concrete structures as it provides the only barrier to the
ingress of water containing dissolved ionic species such as chlorides which, ultimately,
initiate corrosion of the reinforcement. In-situ monitoring of cover-zone concrete is critical in
attempting to make realistic predictions as to the in-service performance of the structure. To
this end, this paper presents developments in a remote interrogation system to allow
continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is
made of a multi-electrode array [19] embedded within cover-zone concrete to acquire
discretized electrical resistivity and temperature measurements, with both parameters
monitored spatially and temporally. On-site, instrumentation, which allows remote
interrogation of concrete samples placed at a marine exposure site, is detailed, together with
data handling and processing procedures. Site-measurements highlight the influence of
temperature on electrical resistivity and an Arrhenius-based temperature correction protocol
is developed using on-site measurements to standardize resistivity data to a reference
temperature; this is an advancement over the use of laboratory-based procedures. The testing
methodology and interrogation system represents an additional technique which could be
used for intelligent monitoring of reinforced concrete structures.