Date of Graduation

8-2022

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor/Mentor

Gary S. Prinz

Committee Member

W. Micah Hale

Second Committee Member

Cameron Murray

Keywords

composite bridge, fatigue, friction, shear stud

Abstract

Composite bridge behavior is commonly achieved through headed shear studs welded tothe steel girder flange and embedded in the concrete deck. Current AASHTO provisions for estimating demands on shear studs during service-level loading consider only bearing load transfer, neglecting adhesion bonding and friction load transfer between the concrete deck and girder flange. Quantifying alternative load transfer mechanisms across the steel-concrete interface may result in improved steel bridge economy by reducing the number of studs required in a composite girder design. This study investigates the effects of flange surface friction (considering various coatings) on resulting stud demands using both experimental testing and analytical modeling. In this study, inorganic zinc primer and cleaned mill-scale surface conditions are considered in analytical simulations, and inorganic zinc primer coatings are considered in double-sided pushout experiments to quantify flange surface coating effects. Thin foil pressure gauges are used to measure stud demands while controlled normal forces are applied to each slab to allow controlled changes in flange friction force during testing. A total of nine experimental tests are conducted. The analytical study involves 32 finite element simulations of pushout geometries having normal forces of 0k, 5k, 10k, 25k, and shear forces of 10k, 15k, 20k, and 25k. Results from both experiments and analyses indicate that moderate increases in applied normal force (10k) result in friction load transfer that reduce stud demands by 86.6% on average. Applied normal forces of 6k resulted in 74% reduction in stud demands when compared to tests having no applied normal force.

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