Bridge engineers are seeking new ways to build better bridges,
reduce work zone travel delays, and reduce maintenance costs. Agencies are challenged
with replacing critical bridge components with minimum disruption to the traveling public.
Using ultra high performance concrete, or UHPC, for precast panels and connection details
is a new application that offers great potential for new and rehabilitation bridge projects
around the country. Wapello County, Iowa was familiar with UHPC and saw its potential.
With the help of an FHWA Highways for LIFE Technology Partnerships grant to Coreslab
Structures, they used UHPC waffle design modular panels and UHPC connections for their Little
Cedar Creek bridge project. The bridge consists of 14 waffle slabs. The bridge deck panels
were manufactured with UHPC and were installed with field cast UHPC connections for bridge
deck continuity. The design is simple, manufacturing is easy, and construction moves quickly. The
lightweight panels will allow rehabilitation without needing to strengthen the substructure
to handle heavier live loads. It also will be possible to rehabilitate a bridge under
traffic by replacing one lane at a time. Dean Bierwagen: The main and – advantages of ultra
high performance concrete is – is you have a very high compressive strength compared
to regular concrete, very high compressive strength; 30,000 psi. So that is one – one
big advantage. The next advantage, because of the the mix that you have a a mix that
s very low in permeability; basically waterproof. I mean it s not going to let any water in.
And then the third advantage, which for us is another big positive for bridge decks,
is the durability. I mean this stuff is very durable under traffic and stuff. It ll, it
ll hold together for a long time, I d say as compared to regular concrete. A decade
of research and deployment efforts have demonstrated that UHPC is a material capable of future
deployment in large scale applications. Field-cast UHPC connections facilitate the use of conventional
prefabricated components throughout bridges by eliminating the weak links common to this
type of construction. Due to concrete s longevity, its efficiency in handling heavier live loads,
and the economy with which structures can be built in a short time, UHPC can enhance
future projects around the country. Brian P. Moore: The advice I d give to other owners
and contractors would be to consider the material. Consider to your application that you re needing.
It s new; it s innovative. But it has a very big potential. So, just don t rule it out
because it s new. Give it a serious consideration for the unique application that you need.
Utilize the properties of the material and give it some consideration as you look forward
to look forward to building new projects. And building products that will extend the
life longer bridges, longer life, lower maintenance costs. UHPC has that potential. As a bridge
owner, being our second project, we ve had a great experience using UHPC. Test results
have been great. The material has performed to this point great, and it s shown great
promise for things to come in the future. Coreslab Structures produced the UHPC waffle
slab components at its Omaha precast plant. They demonstrated that it was possible to
use new materials, such as UHPC, to precast bridge deck components with few alterations
to existing technology and processes. UHPC could change the way bridge decks are constructed
and significantly extend the service life of highway infrastructure as well as open
up new markets for precast manufacturers. The many advantages of UHPC make it a viable
choice for many bridge projects. For more information on the UHPC waffle bridge deck
project visit the Highways for LIFE web site. For more information on UHPC, contact the
structural concrete research program at FHWA’s Turner-Fairbank Highway Research Center.