SOUTHFIELD—Bridges that are more durable, with up to a 100-year service life, will be the focus of a visit by federal, state and local officials to Lawrence Technological University’s Center for Innovative Materials Research (CIMR) on Monday, Aug. 9
U.S. Rep. Brenda Lawrence (D-Southfield) and Michigan Department of Transportation Director Paul Adjeba, along with State Representative Kyra Bolden, Oakland County Executive Dave Coulter, and Southfield Mayor Kenson Siver are scheduled to attend the test featuring advanced bridge materials developed and tested by an LTU team led by Nabil Grace, dean of the LTU College of Engineering.
Matt Chynoweth, Chief Bridge Engineer and Director of the MDOT’s Bureau of Bridges and Structures, is working in collaboration with Grace, the principal investigator on this Federal Highway Administration (FHWA) Pooled Funds Project that was awarded to four State Departments of Transportation—Michigan, the lead on the project, along with Ohio, Maine, and North Carolina.
LTU and MDOT have been collaborating for more than 20 years on using pretensioned carbon fiber reinforced polymer (CFRP) strands in concrete bridge beams, in place of traditional steel prestressing strands. CFRP has the same strength characteristics of steel, but is non-corrosive, and is expected to last much longer than steel.
The latest project—and focus of the Aug. 9 visit—involves the development, testing, and deployment of CFRP strands that are 0.7 inches in diameter, the largest diameter CFRP strands developed and tested to date, plus the integration of a limited amount of ultra -high-performance concrete (UHPC) to connect the bridge beams rigidly together. This will be the first bridge model test of 0.7-inch CFRP pretensioned strands incorporating a limited amount of UHPC. The use of 0.7-inch CFRP strands will allow a reduction in the number of CFRP strands compared to the 0.6-inch diameter stands currently being deployed in CFRP bridges, reducing costs and increasing the overall strength of the bridge.
Based on the bridge model test, it is expected that 0.7-inch CFRP strand bridge design guidelines will be finalized and added to the existing MDOT design guidelines for use in the deployment of CFRP bridges.
To view a live webcast of the demonstration, visit https://youtu.be/z8uu0GW8Kc8 Aug. 9 at 1:10 p.m. Eastern time.
“The MDOT – LTU collaboration, with the assistance of our federal partners over the last 20 years, has established Michigan as a leader in advanced bridge infrastructure using innovative materials that can yield a remarkable 100-year service life,” LTU President Virinder Moudgil said..
MDOT, as the lead in the Department of Transportation Pooled Funds Project, is seeking to build the first two bridges over I-94 in Detroit constructed with 0.7-inch CFRP pretensioned strands. Other DOTs in the Pooled Funds Project will evaluate the new bridge technology for deployment in their states as well.
The Bridge Model Test is also a precursor to advancing the development, testing and deployment of the 0.7-inch CFRP pretensioned strands and full integration and deployment of UHPC in the next few years. UHPC has been demonstrated in testing to have five times the strength of the concrete now used in bridge construction.
Combined, the materials can lead to an MDOT strategic objective of the 100-year service life bridge.
Completed in 2008, LTU’s CIMR is a 7,200-square-foot research facility with a 30-foot clearance height. It has a 25-ton crane to accommodate testing of structural components up to 100 feet long under various types of loads up to one million pounds. It also features a large-scale fire chamber with dynamic and static loading capabilities that can test structural components in temperatures up to 2,400°F, conditions like those of the 9/11.
CIMR also houses an environmental chamber spacious enough for a large vehicle, which can simulate harsh weather conditions such as blowing, freezing rain, sub-zero temperatures of -80°F, or dry heat up to 180°F. Also in the CIMR: small environmental systems that measure the performance of materials when subjected to pulling, twisting and repeated loads, and a chamber that can subject materials to a variety of forces at temperatures ranging from -80°F to 600°F.
Lawrence Technological University, www.ltu.edu, is a private university founded in 1932 that offers nearly 100 programs through the doctoral level in its Colleges of Architecture and Design, Arts and Sciences, Business and Information Technology, and Engineering. PayScale lists Lawrence Tech among the nation’s top 11 percent of universities for the salaries of its graduates, and U.S. News and World Report lists it in the top tier of best Midwestern universities. Students benefit from small class sizes and a real-world, hands-on, “theory and practice” education with an emphasis on leadership. Activities on Lawrence Tech’s 107-acre campus include more than 100 student organizations and NAIA varsity sports.