Summer Meeting Preview

No Boundaries� summer meeting will be held from August 29-31 in Columbus, Ohio. The program�s semiannual meetings represent an important opportunity for participants to engage in technology transfer activities and one-on-one information sharing about a range of topics relevant to non-winter transportation maintenance.

A number of presentation and events in Columbus are sure to generate interest and spark discussions among No Boundaries� members and guests. Planned discussion highlights for the upcoming meeting include:

• Recent innovations in maintenance by No Boundaries members
• State updates on Transportation Systems Management and Operations plans
• Connected vehicle deployment
• Maintenance asset management systems efforts

In addition, tentative field trips and events include:

• Time on the floor at Ohio DOT's "Team Up ODOT" innovations roadeo
• A tour of Ohio DOT's aircraft facility for the State Highway Patrol and Department of Natural Resources at Ohio State University airport
• A tour of the Transportation Research Center, Inc., the largest independent vehicle test facility and proving grounds in the United States
• A visit to Ohio State University's Gwynne Conservation and Research Center � Bee Pollinator Project

Presentation and event highlights will appear in a future issue of this newsletter.

Seeking Input for Webinars

Earlier this year, No Boundaries began developing its new webinar series, which will serve as a platform for accelerated technology transfer with a broad national audience.

To help identify the most useful webinar topics, No Boundaries developed a survey to gather information about innovative state DOT maintenance practices, particularly in the areas of maintenance training, contracting and technology.

All state maintenance and operations personnel are encouraged to participate. Take the survey now.

The survey also provides respondents a chance to detail other maintenance topics that they would like to learn more about through the upcoming webinar series.

New Members Are Welcome

No Boundaries membership stands at 15 state DOTs across the United States: Connecticut, Florida, Illinois, Louisiana, Maryland, Michigan, Missouri, New York, North Dakota, Ohio, Pennsylvania, South Carolina, Virginia, Washington State, and Wisconsin.

As work continues in 2017 and beyond, No Boundaries extends an open invitation to new members.

No Boundaries is Transportation Pooled Fund project #TPF-5(330). State DOT commitments to the project can be made using 100% federal funds. Contact Brian Hirt, CTC & Associates, at 402-770-9067 for more information.

Meetings and Events

Training Opportunities

TRB Webinar: Rigid Pavement Rehabilitation: Looking Back, Looking Forward

TRB will conduct a webinar on rigid pavement rehabilitation on September 5. The webinar will examine how rigid pavement rehabilitation has evolved over the last several decades and will discuss new and innovative rehabilitation solutions. Topics will include full- and partial-depth repairs, load transfer restoration, and concrete overlays.

Asset Management Research

Hotspot and Sampling Analysis for Effective Maintenance and Performance Monitoring
Utah DOT

Due to resource constraints, many agencies assess the condition of their roadways and other assets by inspecting a sample of those assets. This research project investigated two sampling frameworks designed to provide statistically representative samples that reflect the true level of maintenance at the state, region, or maintenance station level. One framework is designed for collecting data on a single type of infrastructure and the other for a network with multiple types. Researchers found that both methods outperformed the simple random sampling method that is widely used across agencies. Report.

Guidelines for Replacement of Deficient Bridges with Low-Water Stream Crossings in the Rural Midwest
Pooled Fund Study TPF-5(318)

In rural areas, counties often cannot afford to replace all deficient bridges, and agencies can be forced to close low-volume roads instead. In some locations, a low-water stream crossing (LWSC) can be a practical, low-cost alternative to bridge replacement. LWSCs are structures that may occasionally be impassable due to floodwaters; they include unvented fords, vented fords, low-water culverts, low-water bottomless culverts, and low-water bridges. This report provides guidance to agencies considering this approach. The lower initial cost of an LWSC must be balanced against maintenance requirements and safety considerations. This study examined nine recent LWSC projects in Kansas, creating case studies that address road and traffic characteristics, stream characteristics and hydrology, governmental permits and regulatory issues, project costs, and maintenance requirements and performance to date. Report.

In Minnesota, the Local Road Research Board recently surveyed state DOTs on a similar topic, publishing a synthesis report on removing low-use bridges as a way to prioritize bridge maintenance at local agencies.

Prediction and Mitigation of Scour and Scour Damage to Vermont Bridges
Vermont Agency of Transportation

Over 300 Vermont bridges were damaged in 2011�s Tropical Storm Irene, and many experienced significant scour. This project sought to develop methods to aid in predicting scour vulnerability by leveraging data on existing Vermont bridges and case studies of bridge scour damage and integrating this information with stream geomorphology data. Researchers found that measures of site-specific stream power correlated with levels of bridge damage sustained during the Tropical Storm Irene. These measures can help predict which bridges are most likely to sustain flood-related damage in the future. The report also makes recommendations for inspection and mitigation procedures. Report.

Bridge Repair and Rehabilitation Research

Evaluation of Repair Techniques for Impact-Damaged Prestressed Beams
Virginia DOT

When an overheight vehicle hits a bridge, damage to the bridge can range from minor to catastrophic, potentially requiring repair or replacement of a bridge beam. For prestressed concrete beams, the traditional repair methods are strand splices and fiber-reinforced polymer (FRP) wraps. This project evaluated and compared several repair techniques, including methods that used a newer material, fabric-reinforced cementitious matrix (FRCM), as an alternative to traditional FRP wrap. The greatest percentage of original strength was restored using the FRP repair and the repair method that combined FRCM and strand splices. The study indicated that FRCM can be an effective component of repair techniques for impact-damaged prestressed beams. Report.

Evaluation of Maintenance Procedures for Bridge Spalling on Parapet Walls
Ohio DOT

Spalling and deterioration of concrete parapet walls can endanger motorists, since pieces of deteriorated concrete may fall onto the road below. Ohio DOT�s current repair method is to chip off the deteriorated concrete, but this process may damage the sound concrete and leaves an unprotected surface. This project used a literature search to explore methods of removing deteriorated concrete and protecting or sealing the remaining surface. Hydrodemolition using a robot was identified as the most promising method of concrete removal since it does not damage the remaining concrete. For sealing the surface, researchers identified polyurea as a promising option. In addition to sealing the concrete, polyurea may provide a reinforcing barrier that could retain loose pieces of concrete. Report.

Cost-Effective Strategies for Repairing Grout in Post-Tensioned Bridges
Minnesota DOT

Post-tensioned bridges, which are strengthened by running steel strands through the concrete members, are especially durable, but the steel strands must be grouted to keep them from corroding. Grouting materials and practices used in about 40 older Minnesota bridges often produced air- or water-filled voids within the grout, which could lead to corrosion and may require repair. A two-phase research effort produced techniques for evaluating these structures and guidelines for managing the process of soliciting and procuring engineering and construction services to repair them. Report and two-page Technical Summary.

In related research:

• The National Cooperative Highway Research Program recently published NCHRP Research Report 848: Inspection Guidelines for Bridge Post-Tensioning and Stay Cable Systems Using NDE Methods. Report.
• Florida DOT recently published a report on applying impedance-based detection of corrosion in post-tensioned cables. Report and one-page Summary.

Culvert Maintenance Research

Best Practices for Assessing Culvert Health and Determining Appropriate Rehabilitation Methods
South Carolina DOT

This research project developed guidance for South Carolina DOT on managing and maintaining culvert infrastructure, including guidance on the latest culvert inspection techniques. The project developed a deterioration model to predict the future condition of culverts; developed a risk-based renewal prioritization model for deteriorating culverts; and developed guidance for selecting renewal methods given the culvert material, size, and user preferences. The models developed for deterioration prediction, risk-based prioritization, and renewal selection can help in short-term and long-term planning of culvert infrastructure maintenance. Report.

In related research:

• The National Cooperative Highway Research Program recently completed NCHRP Project 14-26, which developed the Culvert and Storm Drain System Inspection Manual. AASHTO is currently reviewing the manual for publication. Project page and contractor's final report.
• Minnesota DOT recently published the Enhanced Culvert Inspections Best Practices Guidebook. Report.

Inspection Vehicle Developed In-House Improves Culvert Repair
Minnesota DOT

An enhanced radio-controlled car developed by Minnesota DOT workers is saving the department money by improving culvert inspections. The Hydraulic Inspection Vehicle Explorer (HIVE) takes lights and a camera into culverts and transmits inspection data wirelessly to a tablet. Each vehicle costs roughly $1,500. In one case study, an end-of-pipe inspection showed significant pipe damage that would typically result in a full replacement at a cost of about $45,000. However, HIVE video footage showed that the damage was limited to just 12 feet near the end of the pipe. Instead of replacing the entire pipe, MnDOT workers fixed the problem for $1,000, resulting in a $44,000 savings. The HIVE has also been used to detect deterioration deep within a pipe, allowing damage to be repaired before it progressed. Project page.

Drainage Systems Maintenance Research

Evaluation of Trench and Slotted Drain Maintenance and Cleaning
Ohio DOT

In Ohio, trench and slotted drains are increasingly being used to remove storm water from roadways. These drains must be properly cleaned and maintained to prevent vehicles from hydroplaning, eliminate flooding and avoid premature roadway failure. Researchers documented Ohio DOT's current methods for cleaning trench and slotted drains and recommended alternative cleaning methods that can improve safety, production rate and cost-effectiveness, such as horizontal directional drilling, horizontal auger boring and use of robotic cleaners. Report.

Ohio DOT recently completed a related research report, Effective and Economical Cleaning of Pipes and Underdrains. Report.

Funding and Budgeting Research

Examining the Potential Impacts of Maintenance Investment and Capital Reinvestment in Vermont�s Roadway Infrastructure Network
Vermont Agency of Transportation

This project assessed the current state of the practice of implementing different reinvestment and disinvestment strategies at the state level and examined how those strategies could be employed in Vermont. Researchers identified candidate corridors for disinvestment based on quantifiable measures of how critical the corridors are to traffic flow throughout the roadway network, and considered how disinvestments would impact vulnerable populations and access to critical services. The project developed a framework to help guide Vermont Agency of Transportation in making strategic reinvestment/disinvestment decisions. Report.

Pavement Repair and Rehabilitation Research

Evaluation of Seal Coat Construction Materials
Texas DOT

Through this project, researchers developed Guidelines for TxDOT in Selecting Seal Coat Materials based on tests of aggregates and binders commonly used in Texas. They conducted lab tests to evaluate the durability and wear characteristics of common aggregates, and tested binders for flushing characteristics. They also used field tests to compare seal coat performance in terms of bleeding and aggregate loss. Although many factors can influence seal coat performance, including site selection and construction factors, this research pointed to polymer-modified binders providing greater performance reliability than unmodified binders. Report and Guidelines.

Effects of Tree Canopy on Rural Highway Pavement Condition, Safety, and Maintenance
Ohio DOT

Roadside trees are valued for their natural beauty and because they provide shade, control evaporation, block air movement, catch rain and channel rain wash, and control local humidity. However, road managers tend to believe that the presence of trees accelerates pavement damage through increased surface water pooling, poor density attainment, and other effects. This accelerated damage reduces pavement life and increases maintenance and rehabilitation costs. As a first step in investigating tree canopy impacts on road pavement condition and driver safety, this project produced a synthesis of current practices in Ohio and other states related to tree canopy maintenance. Report.

Validation of Hot-Poured Crack Sealant Performance-Based Guidelines
Pooled Fund Study TPF-5(225)

This pooled fund study undertook a comprehensive effort to validate thresholds for performance-based guidelines and grading systems for hot-poured asphalt crack sealants. This project also evaluated the short-term and long-term aging effects of hot-poured crack sealants through a differential aging test. An extensive field performance study incorporated a wide spectrum of commonly used sealants installed in eight test sites around the United States using two basic treatment methods: clean and seal and rout and seal. Report and Guidelines.

Roadside Maintenance Research

An Innovative Approach to Smarter Mowing, Utilizing Automated Vehicle Location to Enhance Mowing Operations
Minnesota DOT

By providing real-time data on field operations, automated vehicle location (AVL) systems have allowed many DOTs to gain efficiencies in snowplowing and other fleet vehicle operations. Minnesota DOT undertook a pilot project to assess whether AVL could yield similar benefits in mowing operations. Potential benefits include increased ability to locate and avoid mowing noxious weeds (with a resulting reduction in herbicide use), automated reporting, reduced paperwork, and more efficient allocation of operator time. The pilot project allowed MnDOT to address challenges and document lessons learned, and the project�s success provided the basis for continued use of AVL technology during the 2017 season and potentially beyond. Project page.

Evaluating Vegetation Management Practices for Woody and Herbaceous Vegetation
Ohio DOT

This project evaluated vegetation management practices currently used by Ohio DOT districts and recommended changes to increase efficiency and cost-effectiveness, improve safety for workers and roadway users, and improve roadside aesthetics. Researchers recommended that ODOT implement a Roadside Integrated Vegetation Management program that emphasizes safety and environmental stewardship. The recommendations include improvements in herbicide use, equipment management, and staff training. Report.

Subscribe to this newsletter