Field trials on covercrete monitoring sensors

This paper details the application of in situ electrical measurements to st udy cover-zone performance and presents the initial results from a long-ter m field exposure study. Field data are presented from a marine test site, a n urban exposure site and a roadside test site. A range of formalisms are e xploited to allow ease in data interpretation and a simple electrical model is used to show the interrelationship between electrical properties of con crete, pore structure, degree of pore saturation and ionic ingress. Measure ments, to date, indicate that the sensor arrangement embedded within each o f the test specimens is behaving as anticipated from previous laboratory st udies. Water absorption, ongoing hydration and pozzolanic activity are dete cted within the cover zone and, in the case of the marine site, ionic ingre ss is detected in one of the sets of test specimens.