Project Information

Link to Latest Report: Coming Soon

Background:

The structural performance of steel columns is frequently compromised by degradation from corrosion, fatigue, and buckling under extreme loading conditions. The deterioration of steel columns poses a significant risk to structural safety and may result in costly repair projects. Before any upgrading measures, it is essential to address these issues, starting with removing rust. Techniques such as sandblasting can be employed for cleaning off the rust, followed by applying rust preventers, especially in harsh environmental conditions. Additional longitudinal reinforcement may be required to supplement the compromised steel structure when corrosion has significantly degraded the steel columns. Moreover, in urban environments, the noise associated with steel columns on bridges due to vibrations from vehicular loads and thermal expansion is a growing concern. Traditional methods of upgrading, such as the addition of stiffeners or extra steel layers, are often costly, time-consuming, and involve complicated
approaches.

In seismic zones, upgrading and protecting structural members against environmental attacks is critical. The high compressive strength of Ultra-High Performance Concrete (UHPC) and its dense microstructure present a practical solution for upgrading and protecting steel columns. It should be noted that depending on the conditions of the original steel column and upgrading level, incorporation of longitudinal reinforcement may not be necessary.This research aims to investigate the application of UHPC for the retrofitting and upgrading of steel columns, specifically under seismic loading conditions, to comprehend its performance and establish comprehensive design guidelines.

Objective:

The research approach integrates numerical studies and experimental testing to investigate the structural performance of steel columns wrapped with Ultra-High Performance Concrete (UHPC). The primary objective is to assess the structural enhancements provided by UHPC in non-seismic and seismic regions and to develop practical design guidelines from the findings.

Scope:

The proposed project includes several tasks

• Task 1: Literature Review
  • In this task, a comprehensive literature review on UHPC applications in retrofitting will
    be conducted. This will include gathering data on previous case studies, current design
    practices, and standards.
• Task 2: Preliminary Finite Element Modeling and Design of Test Specimens
  • In this task, finite element models will be developed to predict the behavior of steel
    columns encased in UHPC with different configurations. After this task, the design of the
    test specimens will be finalized.
• Task 3: Proof of Concept Experimental Study
  • In this task, several experimental studies as proof of concept will be carried out to verify
    the feasibility of using UHPC in upgrading steel columns.
• Task 4: Analytical Studies and model validation
  • In this task, numerical studies will be conducted to validate the results of finite element
    analyses against the experimental results. Extensive numerical studies will be carried out
    to investigate the performance of UHPC-encased steel columns subjected to different
    loading scenarios.
• Task 5: Final Report
  • In this Task, a full assessment of the findings from Task 1 throughout Task 5 will be
    conducted, and a report will be published, including practical design guidelines for using
    UHPC in upgrading and retrofitting steel columns.

Research Team:
Principal Investigator: Abbas Khodayari, Ph.D.
Co-Principal Investigator: Atorod Azizinamini, Ph.D., P.E.