Graduation Semester and Year
Spring 2026
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Civil Engineering
Department
Civil Engineering
First Advisor
Dr. Nur Yazdani
Second Advisor
Dr. Shih-Ho Chao
Third Advisor
Dr. Juan Antonio Balderrama
Fourth Advisor
Dr. Md Rassel Raihan
Abstract
Precast, prestressed concrete I-girder bridges assume full composite action between girder and deck. Previous field evaluations indicate that the actual Degree of Composite Action (DCA) is lower than the design assumption. This shortfall reduces stiffness, causes excessive deflections, leads to deck deterioration, and necessitates load postings. Current practice lacks quantitative inspection to verify interface condition and an empirical baseline for deterioration. The neutral axis (NA) method, assuming a linear DCA–NA relationship, further complicates accurate measurement. This thesis addresses the deficiencies through a comprehensive investigation involving three studies of a newly constructed precast prestressed I-girder bridge located in Dallas County, Texas. The first study revealed that the roughness of the precast girder top flange was only 8% of the standards set by the American Association of State Highway and Transportation Officials (AASHTO), significantly reducing cohesion and friction by 73% and 40%, respectively. Moreover, concrete strengths exceeded the limits established by the Texas Department of Transportation (TxDOT) at all evaluated stages, raising concerns about potential durability issues, such as alkali-silica reaction and delayed ettringite formation. The second study established a baseline condition for a prestressed concrete I-girder bridge utilizing advanced techniques, including ground-penetrating radar, impact-echo testing, and diagnostic load assessments. Impact-echo testing confirmed that 91.4% of the deck was devoid of delamination. Neutral-axis analysis indicated DCA values near full composite action, with in situ load-rating factors exceeding design benchmarks across all vehicle classes. The third study involved developing a three-dimensional ANSYS finite element model, calibrated with empirical field data and 241 simulations across the Tx28, Tx46, and Tx62 girder families. The results demonstrate that the DCA–NA relationship exhibits a sigmoid rather than a linear progression, indicating that traditional methods tend to produce errors near the mid-range. Ultimately, a closed-form sigmoid assessment, based on section geometry and field-strain data, is proposed for application to Texas I-girder bridges.
Keywords
Bridge, Prestressed concrete I-girder, ANSYS, Composite Action, NDE, Load testing, Surface roughness, Parametric study
Disciplines
Civil Engineering | Structural Engineering
License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Luitel, Balaram, "Partial Deck-Girder Composite Action in Prestressed Concrete I-Girder Bridges" (2026). Civil Engineering Dissertations. 5.
https://mavmatrix.uta.edu/civilengineering_dissertations2/5