Behavior of advanced innovative materials for improved long-term bridge performance
"The dissertation is to present the investigation results and comprehensive understanding of the long-term performance and behavior of innovative construction materials. The materials are applied in bridge engineering in order to either enhance the conventional materials or replace them. The dissertation consists of two major parts: structural steel coatings for corrosion mitigation and thermal behavior of concrete bridge. In First Part, evaluation of advanced structural steel coatings was carried out through laboratory weathering tests (salt-fog resistance test and QUV weathering test), adhesion test, and electrochemical techniques. Fifteen coating systems were evaluated in this part, which covered both coating and recoating systems on bare steel and overcoating systems on existing paint including inorganic zinc / epoxy / polyurethane and calcium sulfonate coat (CAS) currently used by U.S. DOTs. The outcome of the research provides results on performance of three generic coating systems, recommendations of coating application and overcoatability, mechanisms of corrosion development and adhesion loss of polyurea coating systems, and comparison of three major zinc-rich coating systems. Second part presents thermal behavior of concrete beams based on field investigation and FEA simulation. Seasonal, monthly, and daily thermal characterization of L-beam was studied based on two-year temperature data from an instrumented girder of a pedestrian bridge. The thermal behavior was correlated with climate condition (solar irradiation, ambient temperature, and wind speed) at the bridge site. In addition, current AASHTO specification and design guidelines do not address thermal considerations for the girders above deck (L-beams and inverted T-beams). In order to address such issue, thermal gradient distribution and profile of L-beams and inverted T-beams are proposed"--Abstract, page iv.
Missouri University of Science and Technology
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