Title page for ETD etd-05122010-152915


Type of Document Master's Thesis
Author Balakumaran, Soundar Sriram G.
Author's Email Address soundar1@vt.edu
URN etd-05122010-152915
Title Influence of Bridge Deck Concrete Parameters on the Reinforcing Steel Corrosion
Degree Master of Science
Department Civil Engineering
Advisory Committee
Advisor Name Title
Weyers, Richard E. Committee Chair
Brown, Michael C. Committee Member
Moen, Cristopher D. Committee Member
Wright, William J. Committee Member
Keywords
  • Chloride Diffusion
  • Corrosion
  • Macrocell Corrosion
  • Resistivity
  • Reinforced Concrete
Date of Defense 2010-04-28
Availability unrestricted
Abstract
Chloride induced corrosion of steel in concrete is one of the major forms of deterioration mechanisms found in reinforced concrete bridges. Early age corrosion damage reduces the lifespan of the bridges, which results in heavy economic losses. Research has been conducted to identify economic solutions for significantly delaying and/or preventing corrosion damage. Considering the amount of steel reinforcement used in bridge decks, the influence of as constructed parameters including clear spacing between top and bottom reinforcement bars, ratio of cathode to anode areas, and presence of stay-in-place forms on corrosion activity needs to be evaluated.

The influence of the as constructed parameters have been studied using different corrosion assessment methods including resistivity, half-cell potential, linear polarization, chloride content, moisture content, and visual inspection. This study included the clear spacing distances between the anode and cathode of 51, 76, and 102 mm (2, 3, and 4-inch), number of cathodes as 1 and 2, and the presence and absence of stay-in-place forms. Data up to 15 months were taken from a previous study by Smolinski and integrated into the current study period of 35 to 45 months. A trend line may be established to illustrate the changes which took place over the missing time period, from approximately 15 to 35 months, since the specimens were maintained in controlled environment.

Analysis of the data showed that there is a significant difference between the spacing values (2, 3, and 4-inch) through all forms of evaluations. Regarding the other parameters, no significant difference was identified. Variations in resistivity with increasing spacing, even when the water-cement ratio was kept at 0.50, maybe the result of the difference in unit consolidation between the clear spacing specimens. Thus, the corrosion mechanism observed in this study may be resistivity-controlled. Also, autopsy showed that corrosion on the top bars was in general agreement with the measured corrosion activity. The bottom bars had no visible corrosion and the chloride had not penetrated to the bottom bars, regardless of the separation distance between the top and bottom bars. For this laboratory study, the measurements showed that macrocell corrosion influence on the total corrosion was insignificant.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  GBalakumaran_SS_T_2010.pdf 17.38 Mb 01:20:28 00:41:22 00:36:12 00:18:06 00:01:32
  GBalakumaran_SS_T_2010_Copyright.pdf 937.17 Kb 00:04:20 00:02:13 00:01:57 00:00:58 00:00:04

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.