Search
Filters

00449 THE LULING BRIDGE: AN INSIDE STORY

Product Number: 51300-00449-SG
ISBN: 00449 2000 CP
Author: Desmond C. Cook and Ann C. Van Orden
Industry: Highways & Bridges
$0.00
$20.00
$20.00
The corrosion products formed on the interior weathering steel box-sections comprising one vertical support pier of the Luling Bridge in Louisiana, have been analyzed and compared with those formed on atmospherically exposed coupons for which the protective oxide layer is very adherent and stable. It was determined that very high fractions of large particle maghemite form in the hot and humid conditions inside the boxes. The high time-of-wetness also significantly reduces the fraction of nano-phase goethite which forms and this, along with the presence of maghemite, most likely prevents the formation of the adherent protective corrosion coating needed to reduce the long term corrosion of weathering steel. The spectroscopic analysis of the corrosion products was undertaken using Mossbauer spectroscopy, Raman spectrometry and X-ray diffraction, with morphology and elemental composition of the corrosion products being completed using scanning electron microscopy with energy dispersive spectroscopy facilities. The corrosion product composition varied with height of the box-sections in the pier, most likely due to the different local environmental conditions within each enclosed box. In general the corrosion products contained about 30% rnaghemite and 60% goethite which is very different to the compositions found on well protected weathering steels. The compositions were closer to those found on carbon steel structures exposed to a mild marine environment. The large amounts of exfoliation in the form of sheet-like rust within the box-sections, supports the argument that insufficient wet-dry cycling conditions are available for proper protective coating formation. Keywords: Corrosion, weathering steel, protective rust, iron oxides, Mossbauer spectroscopy, Raman spectrometry,superparamagnetism.
The corrosion products formed on the interior weathering steel box-sections comprising one vertical support pier of the Luling Bridge in Louisiana, have been analyzed and compared with those formed on atmospherically exposed coupons for which the protective oxide layer is very adherent and stable. It was determined that very high fractions of large particle maghemite form in the hot and humid conditions inside the boxes. The high time-of-wetness also significantly reduces the fraction of nano-phase goethite which forms and this, along with the presence of maghemite, most likely prevents the formation of the adherent protective corrosion coating needed to reduce the long term corrosion of weathering steel. The spectroscopic analysis of the corrosion products was undertaken using Mossbauer spectroscopy, Raman spectrometry and X-ray diffraction, with morphology and elemental composition of the corrosion products being completed using scanning electron microscopy with energy dispersive spectroscopy facilities. The corrosion product composition varied with height of the box-sections in the pier, most likely due to the different local environmental conditions within each enclosed box. In general the corrosion products contained about 30% rnaghemite and 60% goethite which is very different to the compositions found on well protected weathering steels. The compositions were closer to those found on carbon steel structures exposed to a mild marine environment. The large amounts of exfoliation in the form of sheet-like rust within the box-sections, supports the argument that insufficient wet-dry cycling conditions are available for proper protective coating formation. Keywords: Corrosion, weathering steel, protective rust, iron oxides, Mossbauer spectroscopy, Raman spectrometry,superparamagnetism.
PRICE BREAKS - The more you buy, the more you save
Quantity
1+
5+
Price
$20.00
$20.00
Product tags
Also Purchased
Picture for 00282 MONITORING CORROSION IN AGING SYSTEMS
Available for download

00282 MONITORING CORROSION IN AGING SYSTEMS - NEW POSSIBILITIES AND OLD FUNDAMENTALS

Product Number: 51300-00282-SG
ISBN: 00282 2000 CP
Author: M. Tullmin, P.R. Roberge
$20.00
Picture for 00271 CORROSION DETECTION AND MONITORING
Available for download

00271 CORROSION DETECTION AND MONITORING - A REVIEW

Product Number: 51300-00271-SG
ISBN: 00271 2000 CP
Author: Vinod S. Agarwala, Siraj Ahmad
$20.00
Picture for 00452 Precipitation Runoff and Atmospheric
Available for download

00452 Precipitation Runoff and Atmospheric Corrosion

Product Number: 51300-00452-SG
ISBN: 00452 2000 CP
Author: S. D. Cramer, S. A. Matthes, G. R. Holcomb, B. S. Covino, Jr., and S. J. Bullard
$20.00