Professor Dennis Mertz passed away after a prolonged battle with cancer. He spent a large portion of his professional career working on advancing of the state-of-the-art of bridge engineering. He was a great friend and colleague to many at ACI and ASCE. Joint ACI-ASCE Committee 343, joined with ACI Committees 342 and 348, sponsored four sessions to honor his contributions and achievements in concrete bridge design and evaluation. These sessions highlighted the important work and collaborative efforts that Dr. Mertz had with others at ACI and ASCE on various topics. These sessions also combined the efforts among ACI and ASCE researchers and practitioners in addressing various topics related to the design and evaluation of concrete bridges. The scope and outcome of the sessions are relevant to ACI’s mission. They raise awareness on established design methodologies applied for various limit states covering topics related flexure, shear, fatigue, torsion, etc. They address problems related to emerging design and evaluation approaches and recent development in design practices, code standards, and related applications. The Symposium Publication (SP) is expected to be an important reference in relation to design philosophies and evaluation methods of new and existing concrete bridges and structures.

This paper provides a description and design developments of the extradosed prestressed bridge concept. The development of the extradosed prestressed bridge concept is discussed, drawing upon the differences with a cable-stayed bridge type. Proportioning parameters used for initial concept development or verification are provided. This includes recommendations on span ranges, structure depth, tower height and multi-span applicability. Stay cable design considerations are discussed. These proportioning parameters are applied to a prototype design, the Pearl Harbor Memorial Bridge. Aesthetic opportunities for this new bridge type are discussed.

Dr. Dennis Mertz was involved with the AASHTO LRFD Bridge Design Specifications [1] for 30 years. Starting with the original development of the specifications and continuing with maintenance and related course development and presentations. His last major contribution to the Specifications was to serve as Principal Investigator for the reorganization of Section 5, Concrete Structures. This presentation summarizes the changes to the structure of the Section including the increased emphasis on design of “B” and “D” regions of flexural members and introduces new and expanded material on beam ledges and inverted T-caps, shear and torsion, anchors, strut and tie modeling and durability. The product of this work was included in the 8th Edition of the Specifications as a complete replacement of Section 5.

With over 80 years of history, it is only in the last 20 years that the use of fiber reinforced polymer (FRP) materials has become feasible for bridge applications in part due to the ever increasing requirement to make structures last longer, with the current American Association of State Highway Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications requiring that structures be designed for a 75 year design life; but also in the development of cost effective production techniques, and the introduction of FRP materials, which bring the cost and strength of FRP materials closer to traditional steel reinforcement. Published documents provide comprehensive recommendations on design methodology, predictive equations, and recommendations for strength and service limits states. In this paper, the background of FRP-prestressed concrete bridges is discussed and trial bridges are designed. Research needs to advance the state of the art are identified and delineated.

The maintenance and management of segmental-concrete cable-stayed bridges represents a major investment of human and financial capital. One possible approach to reducing this cost while simultaneously improving the process, is by using structural health monitoring (SHM) systems. The Delaware Department of Transportation (DelDOT), working collaboratively with the University of Delaware (UD) Center for Innovative Bridge Engineering, installed a comprehensive SHM system on the 1,749 ft (533 m) long Indian River Inlet Bridge (IRIB) during construction. The SHM system is fiber-optic based with more than 120 sensors of varying type distributed throughout the bridge. Within the first year of service, a series of three controlled diagnostic load tests were conducted utilizing the installed SHM system. The test results have been used to establish a standard set of truck passes for future tests, and the recorded response has been used to establish a baseline against which future test results can be compared. These comparisons will yield a quantitative measure of how the bridge is performing, and in combination with the more qualitative biennial inspections, will enable DelDOT to better manage this critical infrastructure asset.