A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Embedded chloride detectors for roadways and bridges
The problems associated with the application of chloride-based deicing agents to roadways and specifically bridges include chemical pollution and accelerated corrosion of strength members (especially rebar) within the structure. In many instances, local ordances are attempting to force state agencies to reduce, if not eliminate, the use of these chlorides (typically at the cost of increased driving hazards). With respect to the corrosion aspects of chloride applications, cracks that occur in the roadway/bridge pavement allow water to seep into the pavement carrying the chloride to the rebar with the resultant increase in corrosion. In response to this problem, particularly in high roadsalt usage areas, a chloride/water impermeable membrane is placed above thr rebar matrix so if/when roadway cracking occurs, the roadsalts won't be able to damage the rebar. Such a membrane is costly - and the question of its in-service performance is questionable. In a joint effort between the University of Vermont and the Vermont Agency of Transportation, the authors are developing fiber optic chloride detectors which are capable of being embedded into the rebar-concrete roadway under this membrane. The sensing mechanism relies on spectroscopic analysis of a chemical reaction of chloride and reagents (which have been coated onto the ends of fibers). Laboratory results of these detectors and a usable system configuration are presented.
Embedded chloride detectors for roadways and bridges
The problems associated with the application of chloride-based deicing agents to roadways and specifically bridges include chemical pollution and accelerated corrosion of strength members (especially rebar) within the structure. In many instances, local ordances are attempting to force state agencies to reduce, if not eliminate, the use of these chlorides (typically at the cost of increased driving hazards). With respect to the corrosion aspects of chloride applications, cracks that occur in the roadway/bridge pavement allow water to seep into the pavement carrying the chloride to the rebar with the resultant increase in corrosion. In response to this problem, particularly in high roadsalt usage areas, a chloride/water impermeable membrane is placed above thr rebar matrix so if/when roadway cracking occurs, the roadsalts won't be able to damage the rebar. Such a membrane is costly - and the question of its in-service performance is questionable. In a joint effort between the University of Vermont and the Vermont Agency of Transportation, the authors are developing fiber optic chloride detectors which are capable of being embedded into the rebar-concrete roadway under this membrane. The sensing mechanism relies on spectroscopic analysis of a chemical reaction of chloride and reagents (which have been coated onto the ends of fibers). Laboratory results of these detectors and a usable system configuration are presented.
Embedded chloride detectors for roadways and bridges
Eingebettete Chloriddetektoren für Straßen und Brücken
Fuhr, P.L. (author) / Huston, D.R. (author) / McPadden, A.J. (author) / Cauley, R.F. (author)
1996
9 Seiten, 4 Bilder, 15 Quellen
Conference paper
English
Embedded chloride detectors for roadways and bridges
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