Bridge in Maricopa County (AZ) Repaired with Innovative Fiber-reinforced Concrete Materials

Concrete used for road and bridge repair has traditionally been reinforced against tensional forces with steel rebar, adding costs and labor to the many repair projects nationwide. Concrete is brittle and as the roads and bridges age shrinkage cracks form leading to corrosion of the steel and to costly structural damage.

Teams from Arizona State University’s (ASU) School of Sustainable Engineering and the Built Environment’s Structural Mechanics and Infrastructure Materials and Cement and Concrete Materials laboratories, the Arizona Department of Transportation (DOT), and Maricopa County DOT partnered to develop an ultra-high-performance concrete (UHPC) to connect bridge elements.

The fiber-reinforced concrete was created from locally sourced materials and the fibers strengthen the concrete material allowing engineers to redistribute the same amount of rebar with smaller fibers. The result is a faster and less costly repair process, cutting project time from six months down to as few as 10 days.

An actual-size reinforced concrete section was evaluated in the ASU lab for sheer, compressive, and tensile strength as well as fatigue resistance. With successful test results achieved, the grout and key joints on a bridge in Maricopa County were filled with new UHPC instead of the traditional rebar-and-concrete resulting in a faster and less costly repair of the bridge.

“The grout key is supposed to help transfer load from one slab to the adjacent slab to help carry the load,” Barzin Mobasher, Ph.D., P.E., M.ASCE, a civil engineering professor at Arizona State University explained. “When the grout goes bad, the slab has to carry all the load by itself. By putting these UHPC keys back in there, we can get the structure back to where it acts as a unit instead of a bunch of individual slabs.” “I think it’s important when agencies and universities work together that they get some of the key players involved, meet often, and try to help each other,” Jimmy Camp, P.E., M.ASCE, a bridge engineering manager at Maricopa County Department of Transportation said. “It is a very collaborative effort that needs to take place; otherwise, it’s just not going to happen with some of these newer technologies.”

The post Bridge in Maricopa County (AZ) Repaired with Innovative Fiber-reinforced Concrete Materials appeared first on American Composites Manufacturers Association.