Evaluation of the effectiveness of deep polymer impregnation as a corrosion abatement technique for overlaid bridge decks

The focus of this research was primarily on corrosion of the reinforcing steel (rebars) in bridge decks. It has been estimated that over $20 billion is required to repair or rehabilitate corrosion induced deficient bridge decks and that the cost is rising at the rate of $0.5 billion annually. Corrosion occurs when there is a sufficiently high concentration of chloride ions at the top rebar mat. The principal source of chloride ions is from the deicing salts applied on the decks during winter. More than 9 million tons of deicing salts are consumed each year in the U.S.A. As corrosion products have a larger volume than steel, corrosion causes cracking and spalling of the deck. Concrete laboratory specimens with rebars were cast and subjected to a chloride environment. The corrosion potential and rate were monitored with Cu-CuSO₄ half-cell and the 3LP device, respectively. When active corrosion had been initiated, the specimens were treated in six ways, one being the 'control'. Two overlay types and polymer impregnation were used in all combinations as treatment methods. The specimens which were impregnated were grooved and dried to 230 °F prior to impregnation and polymerization. The post-treatment corrosion rates were appreciably reduced. Mortar cubes were made, dried to different temperatures between room temperature and 600 °F, impregnated and polymerized. The cubes were then vacuum saturated and their resistivity obtained. They were then cut, dried to 220 °F and the effects of drying temperature was evaluated using a Mercury Porosimeter and a Scanning Electron Microscope. The cubes were subjected to a chloride environment and subsequent chloride content was determined. The results suggested that a lower drying temperature was sufficient for effective impregnation. Other laboratory specimens were dried to 150 °F and 180 °F and impregnated as before. The post treatment corrosion rates supported the conclusions determined in the cube study.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1991

Author dc:creator

• Dutta, Tapas

Chair dc:contributor.committeechair

• Weyers, Richard E.

Committee members dc:contributor.committeemember

• Drew, Donald R.
• Walker, Richard D.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-08042009-040334

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44154