Prefabricated Barrier System Utilizing Ultra-High Performance Concrete Connections

Authors

Abbas Khodayari, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Civil Engineering

First Advisor's Name

Atorod Azizinamini

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Armin Mehrabi

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

David Garber

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Ioannis Zisis

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Wallied Orabi

Fifth Advisor's Committee Title

Committee Member

Keywords

Ultra-High Performance Concrete, Prefabricated Concrete Barriers, Accelerated Bridge Construction, Static Behavior, NonLinear Finite Element Analysis

Date of Defense

6-29-2023

Abstract

In this study, a set of details for barrier-to-deck connections using Ultra-High Performance Concrete (UHPC) are proposed. The use of UHPC allows for shorter development length and lap splice length for dowel bars, and the material characteristics provide strength and durability to the connection. Component-level testing was conducted on a conventional cast-in-place (CIP) detail and two versions of connections using UHPC. Two connection details included a UHPC connection within the barrier segment (U-shape connection) and a UHPC connection in a recess inside the bridge deck (recessed connection). Besides simplified details, the construction sequence of the proposed recessed connection is suitable for Accelerated Bridge Construction (ABC) applications. It is observed that the proposed U-shape connection detail is emulative of the equivalent CIP concrete barrier system. However, the recessed connection system shows significantly improved structural performance compared to the existing CIP and prefabricated barrier systems. The results of the component-level testing were used to validate the results of Non-Linear Finite Element Analysis (NLFEA). These validated models were used to investigate the structural performance of conventional 15-ft long barrier modules connected to the deck overhang using the recessed connection. The model was subjected to transverse loading at its end according to the TL-4-2 loading conditions recommended by NCHRP Project 22-20(2). If a longitudinal barrier can withstand these design impact loads applied to its impact area, it is expected to perform satisfactorily in a corresponding full-scale crash test, resulting only in minor concrete cracking in the deck overhang and the barrier. The NLFEA results showed that the proposed barrier system meets the strength requirement for the corresponding test level. A full-scale experimental test setup was designed as a proof of concept to investigate the structural adequacy of the developed 15-ft long prefabricated barrier system using the Recessed connection subjected to transverse loading at its end. It was reasoned that if the developed barrier system meets the required design load subjected to eccentric loading at its end, its structural adequacy subjected to other less demanding scenarios is confirmed. Therefore, the barrier-to-barrier connections may not be necessary, simplifying the construction process and avoiding complicated detailing requirements. The full-scale experimental testing verified the structural adequacy of the developed system subjected to the most severe eccentric loading conditions according to the TL-4-2 requirements. The behavior of the test specimen and the failure mechanism was described using abundant data, including load-deflection and strain responses and photographs during the failure process. Finally, the numerical models were validated against the full-scale experimental results. The validated model was used to assess the structural performance of concrete barriers subjected to eccentric end loading with different configurations. It was found that the current AASHTO LRFD flexural provisions for designing longitudinal CIP barriers and their supporting deck overhangs for impacts at exterior regions may lead to significantly overdesigned deck overhangs that might not significantly contribute to the ultimate load-carrying capacity of the system. Additionally, the calculated capacity based on the yield line analysis recommended by AASHTO LRFD may not offer a conservative estimate, as traditionally expected from design codes.

Identifier

FIDC011117

ORCID

0000-0002-5955-7597

Previously Published In

Khodayari, A., Mantawy, I. M., & Azizinamini, A. (2023). Experimental and Numerical Investigation of Prefabricated Concrete Barrier Systems Using Ultra-High-Performance Concrete. Transportation Research Record, 0(0). https://doi.org/10.1177/03611981231162591

Recommended Citation

Khodayari, Abbas, "Prefabricated Barrier System Utilizing Ultra-High Performance Concrete Connections" (2023). FIU Electronic Theses and Dissertations. 5457.
https://digitalcommons.fiu.edu/etd/5457