Engineering Commons^™

Virtual Microstructure Generation Of Asphaltic Mixtures, Mohammad Haft-Javaherian

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis describes the development and application of a virtual microstructure generator incorporated with post-processing image analysis methods that can be used to fabricate a virtual, two-dimensional microstructure of asphaltic mixtures. In the generator, geometrical characteristics such as aggregate gradation, aggregate area fraction, angularity, orientation, and elongation were used to transform data from a three-dimensional (3D) mixture into its two-dimensional (2D) microstructure. The 2D virtual microstructures were generated from real 3D mixture information of asphaltic composites. Resulting virtual microstructures were then compared to real cross-sectional microstructure images obtained from actual samples for validation. Comparison presented a good agreement between the …

Delayed Composite Action Coupled With Post-Tensioning For Cast In Place Bridge Deck Systems, Nathanael J. Toenies

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Cast-in-place bridge decks are known to have transverse cracking early in the life of the bridge due to shrinkage and temperature effects. The cracks result from immediate composite behavior between the girder and the deck. For steel bridges, this bond is caused by shear studs welded to the steel beams and embedded in the cast-in-place deck. Prevention or closure of these cracks could greatly increase the durability of the bridge.

The following research focuses on introducing a system that will have delayed composite action, allowing strain in the concrete before it becomes composite with the girder. The system is meant …