 Full Depth UHPC Waffle Bridge Deck Panels
Highways for LIFE Partnerships 2009 Award $382,971
PDF Version (3.4 mb)
Need for Innovation
Bridge engineers are seeking new ways to build better bridges, reduce work zone travel delays, and
improve repair techniques thereby reducing maintenance. Additionally, owners are challenged with replacing
critical bridge components (particularly bridge decks) during limited or overnight road closure
periods. Precast panels manufactured from UHPC can provide significant durability improvements to bridge decks due to the
high strength, extremely low permeability, and improved connection details inherent in the
system. The use of this innovation will result in reduced construction time for new and
rehabilitated bridges, the ability to upgrade the load-carrying cap city of existing bridges, and improved durability of bridge decks.
Project Overview
Coreslab Structures (Omaha), Inc., demonstrated waffle design modular panels on a bridge project in Wapello County, Iowa. The bridge deck panels will be manufactured with ultra-high performance concrete (UHPC) and installed with field cast UHPC joints which fully develop the joint reinforcement for bridge deck continuity. The demonstration bridge is 33’2” wide by 60’ long, consisting of 14 waffle slabs. A specific instrumentation plan will be developed to evaluate the structural performance of the bridge using strain, deflection, and acceleration sensors.
Project Status
Fatigue, load and skid resistance tests conducted by Iowa State University exceeded expectations. The demonstration panels have been cast, cured, and are ready to be shipped. Construction of the demonstration bridge is scheduled for the spring of 2011.
Final Setup of the Phase 1 Specimen.
The panels are cast in an inverted orientation to allow the driving surface to be cast into the demonstration bridge panels with the use of a form liner.
Placing the UHPC.
The UHPC is placed with a specially designed bucket, which aligns the steel fibers in the longest direction of the panel. This helps to increase the flexural strength of the panels.
Setting the Pans.
The form is filled with UHPC and then the pans are set as an assembly. By placing the pans as an assembly, the panels can be cast substantially faster and with less chance of error.
Side Forms and Pans Removed. The side forms and pans are removed once the UHPC reaches 5000 psi compressive strength to allow the UHPC to shrink unrestrained.
Underside of Bridge
Completed Bridge
Additional Information
Project Status
Completed in November 2011, the structural performance of the bridge is being monitored by Wapello County, Iowa.
Project Team
Coreslab Structures (Omaha), Inc.
Lafarge North America, Inc.
Iowa DOT
Iowa State University
Wapello County, Iowa
Contact Information
Highways for Life
Technology Partnerships Program
Julie Zirlin, 202-366-9105
www.fhwa.dot.gov/hfl
Coreslab Structures (Omaha), Inc.
John Heimann, 402-291-0733 ext. 407
www.coreslab.com
jheimann@coreslab.com
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