Nabil F. Grace Ph.D, PE
Designers of Innovative Bridge Win Highest Engineering Award
Southfield, Mich. - Lawrence Technological University (LTU), and Hubbell, Roth & Clark Inc. Consulting Engineers (HRC), recently received state and national awards for their engineering achievements related to the Bridge Street Bridge project in Southfield. (Editor's note: see separate photo attachment; caption at end of release.)
The American Consulting Engineers Council (ACEC) of Michigan, and the Michigan Society of Professional Engineers awarded the engineering design and research team the Eminent Conceptor Award the highest award for engineering excellence for outstanding achievement for an engineering or surveying project.
At the ACEC Engineering Excellence Awards Gala in Washington D.C., Lawrence Tech President Charles M. Chambers accepted the ACEC Honor Award, along with Southfield Mayor Brenda Lawrence and HRC Vice President George Hubbell. The annual ACEC Engineering Excellence design competition celebrates the greatest engineering achievements of the year that demonstrate the highest degree of merit and ingenuity.
Both awards recognized HRC's outstanding engineering work and the pioneering efforts of Nabil Grace, professor and chair of civil engineering at Lawrence Tech. Over a 10-year period, Grace developed a revolutionary concept using carbon fiber reinforced polymers (CFRP) in prestressed concrete highway bridges. Grace and a team of Lawrence Tech students performed extensive laboratory testing, funded by the National Science Foundation and others, to prove the strength of the innovative CFRP design. These government-funded investigations were conducted in the Structural Testing Center (STC) at Lawrence Tech. The state-of-the-art STC is one of the largest such testing facilities in Michigan.
As a result of Grace's research, the University collaborated with HRC and the City of Southfield to replace the outbound lane of the failing Bridge St. Bridge as a full-scale national demonstration project using the new technology. Computer sensors placed in the new Bridge St. Bridge allow the design team and the City to monitor the bridge's performance over time, and compare it to the performance of the conventional steel-reinforced span that carries in-bound traffic. The $8 million project was built with funding from the Federal Highway Administration and the City of Southfield.
CFRP products are made from very thin fibers of carbon, about the diameter of a human hair, said Grace. These long fibers are woven together and encased in epoxy to optimize bridge durability. The greatest advantage of the CFRP concept over conventional steel is that it is much less susceptible to corrosion, he explained. Corrosion from deicing chemicals is the leading cause for concrete deck and bridge beam repair and replacement. Therefore, the on-going research will demonstrate the long-term economic benefits of CFRP over conventional steel reinforced bridges.
This is the first completed multi-span concrete highway bridge in the world to be prestressed and reinforced with CFRP tendons and rods instead of metal cables. There are no existing standards developed by private, state or government agencies in the U.S.. Therefore Lawrence Tech, HRC, the City of Southfield, and Japanese manufacturing firms worked together to research the design, coordinate material testing and determine design criteria and construction standards for this unique CFRP bridge design concept.
The Bridge Street Bridge serves as the sole access to over 50 businesses within the Bridge Street Industrial Park, a major artery to Southfield's vital industrial traffic. Using the CFRP design concept, the City has solved a critical infrastructure problem with a unique and first-of-its kind bridge that may very well represent the future of America's highway bridge construction technology.
Other team members on the project included: the University of Windsor; Construction Technology Laboratories, Skokie, Ill.; Prestressed Systems Inc., Windsor Ontario; Mitsui & Co. (USA) Inc., Cleveland; Sumitomo Corporation of America, New York; and Autocon Composites Inc., Toronto.
Lawrence Technological University offers nearly 50 undergraduate, masters and doctoral degree programs in Colleges of Architecture and Design, Arts and Sciences, Engineering, and Management. Lawrence Tech pioneered the offering of day and evening classes 70 years ago, and now has a growing number of weekend programs. The University's Division of Continuing Education offers courses in leadership and management, computer science, insurance, engineering and more. Lawrence Tech also is home to the Advanced Technology Academy, a charter high school offering a challenging curriculum closely linked to the University's academic mission.