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Behind the bridge slide: dish soap and a lot of planning
Using Dawn dish soap to grease the rails, MnDOT crews inched the new Larpenteur Avenue Bridge into place two weeks ago using an innovative construction method. As the bridge reopens to traffic tonight...
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Video: Load Testing for the Winona bridge
New video, below, shows how explosions are used to test the bedrock for the new Highway 43 bridge in Winona. Bridge engineers use “pile load testing” to find out how much weight and resistance the...
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Using History to Predict Bridge Deck Deterioration
Just how long will it be before a bridge deck needs to be rehabilitated? Why not look to history to find out? Researchers have put several decades of MnDOT bridge inspection records to good use by...
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Riprap grout protects bridge abutments
Bridges over Minnesota waterways need to be protected from currents by a field of interlocking angular rocks called riprap. Without these rocks along the abutment, moving water could wear away the soil...
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Using drones to inspect bridges
MnDOT is researching how data and images collected by drones, such as the Aeryon Skyranger shown here, could aid bridge inspectors. In recent years, drones made headlines for fighting wars overseas,...
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I-35W ‘Smart Bridge’ Test Site Uses Vibration Data to Detect Bridge Defects
By analyzing vibration data from the I-35W St. Anthony Falls Bridge, MnDOT is working to develop monitoring systems that could detect structural defects early on and ultimately allow engineers to...
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New Study: Experimental Shear Capacity Comparison Between Repaired and...
MnDOT Research Services recently executed a contract with the University of Minnesota to begin work on a research study titled “Experimental Shear Capacity Comparison between Repaired and Unrepaired...
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A Look at Local Bridge Removal Practices and Policies
Many local agencies in Minnesota lack funding to construct and maintain all the bridges in their roadway network. One way to lower costs is to reduce the number of bridges. In Minnesota, some township...
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New Project: Creating a Tool to Estimate Bridge Construction Time and Costs
MnDOT recently executed a contract with WSB & Associates Inc. to begin work on a research project titled “Bridge Construction Time and Costs.” The research project will help the State of...
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MnDOT Improves on Award-Winning Use of Drones for Bridge Inspection
MnDOT’s efforts to study whether drones can help bridge inspectors are progressing, and the second phase project has been completed. (Meanwhile, a third project has just begun.) Phase 1 of this...
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New Project: Phase 3 of Drone Bridge Inspection Research Focuses on Confined...
MnDOT recently entered into a contract with Collins Engineers Inc. to complete a third phase of research testing drones for bridge inspections, with a new focus on confined spaces. This Phase 3 project...
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Cost-Effective Strategies for Repairing Grout in Post-Tensioned Bridges
Researchers provided recommendations and general guidance to assist MnDOT in developing cost-effective strategies for future investigation and repair contracts of post-tensioned bridges built in...
View ArticleUsing Chemical Adhesives to Post-Install Epoxy-Coated Rebar in Concrete
The Minnesota Department of Transportation (MnDOT) had suspended the use of post-installed epoxy-coated rebar for concrete barrier repairs as a precautionary measure because chemical adhesives used in...
View ArticleNew Project: Use of Innovative Technology to temporarily Deter Bat-Bridge Use...
MnDOT has funded a study to evaluate the use of non-lethal ultrasonic acoustic devices to temporarily deter bats from bridges before and during construction projects. Background When protected bats...
View ArticleUsing Debonded Strands to Reduce End Stress in Bridge Beams
A new MnDOT-funded research study has found that most agencies in states with weather similar to Minnesota’s use debonded strands in prestressed concrete bridge beams. MnDOT may begin piloting...
View ArticleDetecting Corrosion Early Extends Service Life of Bridge Paint Coating
An evaluation of five maintenance paint coating systems on Minnesota steel bridges with localized corrosion found that each maintenance coating performed well, and, if corrosion is identified early and...
View ArticlePutting Research Into Practice: New Tool Estimates Bridge Construction Time
A new spreadsheet tool developed by the Minnesota Department of Transportation draws on historical data to help project engineers better estimate bridge construction time. The method allows users to...
View ArticleMethods to Mitigate Bridge Corrosion Show Mixed Results 20 Years Later
Well-documented efforts undertaken two decades ago to mitigate corrosion of a Highway 394 reinforced concrete bridge have given researchers the perfect scenario for evaluating the treatments’ long-term...
View ArticleGFRP Rebar Shows Promise for Use in Bridge Decks
Reinforced concrete bridges are built to handle heavy loads and routine traffic for 75 years or more. But bridges in climates like Minnesota’s are exposed to moisture and chlorides from road salts that...
View ArticleNew Project: Bridge Low Slump Concrete Overlay Mix Design for Mobile Mixers
In recent years, MnDOT has seen an increase in cracking of low slump overlays. Cracking of overlays allows chlorides to get into the bridge deck which leads to deterioration of the reinforcement and...
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