Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/521868
EquipmentWorld.com | June 2015 61 during bridge replacement jobs. Helping make it all possible is a revolution in construction materials and methods, like carbon fiber-rein- forced columns and deck panels. At the same time, the design and construction of longer-life bridges is gaining new attention. New research details how bridges may be con- structed to exceed a century of ser- vice life. This is significant, as many precast, prestressed, post-tensioned cable-stay bridges constructed in the 1980s already have experienced one- third of their projected service lives. Now, both of these trends – ac- celerated bridge construction and longer lives – have received new momentum from the second Stra- tegic Highway Research Program (SHRP 2) which sought to create breakthroughs in transportation problems by using concentrated resources over a short time frame. The nine-year SHRP 2 program ended in March 2015 and research "products" are making their way into the field (see SHRP 2 Research sidebar on page 69). Together they comprise a powerful resource for state departments of transportation to use to re-evaluate bridge designs for longer life spans. Accelerated bridge construction Accelerated bridge construction (ABC) requires a completely dif- ferent approach to the design and erection of bridges than was con- ventional just a decade ago. Driven by the Federal Highway Administra- tion's Every Day Counts initiative – which intends to shorten project delivery while enhancing roadway safety and protecting the environ- ment – innovative, accelerated bridge designs are being promoted by FHWA among the state DOTs. "DOTs can replace bridges within 48 to 72 hours and reduce planning and bridge construction efforts by years," FHWA maintains. "The ac- celerated project times significantly reduce traffic delays and road clo- sures and could potentially reduce In 2013 in Creek County, Okla- homa, the Oklahoma DOT used accelerated bridge construction methods to replace the 300-foot- long S.R. 51 bridge over Cottonwood Creek; here new piers are constructed beneath existing bridge, which stays open during construction. In 2012 in Minnesota, precast girders await precast deck panels as part of PBES- enabled accelated bridge construction process. Photo: FHWA Photo: Oklahoma DOT