Hassan H. Abbas

Rapid Bridge Deck Replacement Construction Techniques: State of the Practice

Rapid bridge deck replacement (RBDR) is the method of replacing a bridge deck using innovative, alternative deck systems to perform needed repair under an accelerated construction schedule. Through employing RBDR techniques, state highway agencies (SHAs) can meet current transportation challenges by repairing the nations bridges while minimizing construction-related impacts. SHAs in the United States were surveyed on their experience with RBDR projects. Survey results are divided into the following categories: decision-making factors, construction schedules, construction techniques, contractual methods, costs, and innovations in safety or technology employed. Of the 52 responding agencies, 24 have experience with RBDR; 54% have less than 5 years of experience, and 63% have completed fewer than five RBDR projects, suggesting that the practice is new and most agencies are inexperienced. The strongest factors influencing decision making are traffic volume, critical bridge, safety, and impact on local business. Most RBDR projects are performed on highways and freeways, in both urban and rural areas. Lane closures are the most common closure scenario, which allows construction to proceed while maintaining partial throughput capacity. Most agencies use nighttime closures, which reduces road user impact and provides a safer environment. Although 86% of the responding agencies experienced an increase in construction costs, 68% agreed that RBDR projects are perceived as a cost-saving mechanism for road users. Information collected from this survey, along with lessons learned and safety and construction technologies employed, allow knowledge to be transferred to practitioners who may have little or no experience with RBDR techniques.

INNOVATIVE HIGH PERFORMANCE STEEL GIRDERS FOR HIGHWAY BRIDGES

Innovative bridge girders have been proposed to overcome design limits related to use of high performance steel. This paper focuses on I-shaped girders with corrugated webs and I-shaped girders with tubular flanges. Design criteria are offered and limited design studies showing some advantages of these innovations are given.

Review of Current AASHTO Fatigue Design Specifications for Stud Shear Connectors

Fatigue design provisions for stud shear connectors in the current AASHTO LRFD Bridge Design Specifications are based on the research conducted in the mid 1960s by Slutter and Fisher, who tested 44 push-out specimens to determine the fatigue life of the shear connector. An analysis of test data produced by Slutter and Fisher and an examination of the current AASHTO design provisions in comparison with their European and Japanese counterparts suggest that the AASHTO may significantly underestimate the fatigue life of stud shear connectors, especially in the range of fatigue behavior where most bridges are designed. A design example is presented that demonstrates that the required number of studs according to the AASHTO can be more than twice the number required by other design codes in Europe and Japan. A possible reason for this discrepancy is discussed.

Full-Scale Implementation and Testing of Full-Depth Precast Bridge Deck Panels

A bridge deck panel system using nonprestressed full-depth precast concrete bridge deck panels with continuous shear pockets was investigated. First, the research team performed conceptual improvement, design, detailing, and fabrication studies on a specific deck replacement system (System CD-2) previously proposed by NCHRP Project 12-65 researchers. Key improvements to the CD-2 deck panel system included modifications to the transverse joint coupler for ease of construction and the addition of a longitudinal staged-construction joint to expedite bridge deck replacement projects. Next, an experimental program was carried out to construct and perform service-level load testing on a full-size precast deck panel assemblage that incorporated the refinements. On the basis of static and cyclic loading test results, it was found that the modified CD-2 deck panel system as a whole performed satisfactorily with regard to AASHTO serviceability requirements.