The Portland Cement Association defines
Ultra-High Performance Concrete (UHPC) as “high-strength, ductile material
formulated by combining portland cement, silica fume, quartz flour, fine silica
sand, high-range water reducer, water, and steel or organic fibers. The
material provides compressive strengths up to 29,000 pounds per square inch
(psi) and flexural strengths up to 7,000 psi.”
The high performance fiber reinforced concrete offers the advantage of
strength, ductility, durability without the need of reinforcing steel
rebar.
One of the first projects to use UHPC was
the Shawnessy Light Rail Transit (LRT) Station in 2003 in Calgary,
Alberta. The project consisted of a roof
designed with 24 thin-shelled canopies 16 x 20 feet. Designed by Enzo Vicenzino of the CPV Group
Architects Ltd, the precast UPHC shell was only .79 inches thick and had a
specified requirement of 19,000 psi. By
using the UPHC, it provided the project with features such as superior
ductility, strength, and durability.
Another project that used UPHC as its
construction material was the Mars Hill Bridge in Wapello County in Iowa. Opened in 2006, the bridge is a simple, single-span
bridge constructed with three 110-foot long precast UPHC girders that do not
contain any shear reinforcement. The
beams are topped with a cast-in-place concrete bridge deck.
The Federal Highway Administration reports
that UHPC is being studied for use in a wide variety of highway infrastructure
applications. They state that, “the high compressive and tensile strengths
allow for the redesign and optimization of structural elements.” They further
explain that the “enhanced durability properties facilitate a lengthening of
design life and allow for potential use as thin overlays, claddings, or shells.”
Currently UHPC is being used in
prestressed concrete girder simple-span bridges, precast concrete deck panels,
and field-cast connections between prefabricated bridge components.
The Conco Companies’ mission
is to be the best supplier of concrete services in the Western United States
and to bring expertise, experience and quality to each project. We continue to upgrade and expand facilities
to better serve the growing market for public works projects, commercial,
parking structures, educational, and other construction development. We have
offices in California, Washington State, Oregon, Colorado and Nevada.
Sources:cement.org/for-concrete-books-learning/concrete-technology/concrete-design-production/ultra-high-performance-concrete
sustainableprecast.ca/downloads/USE_OF_UHPFRC.pdf
fhwa.dot.gov/research/resources/uhpc/
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