Worel, Benjamin J.

State and local agencies often face the challenge of managing their pavement networks with limited resources. The natural degradation of new pavements, influenced by traffic loads and environmental factors, necessitates attention. Extending the service life of pavements without resorting to costly rehabilitation or reconstruction activities is feasible through timely application of appropriate treatments while the pavement is still in satisfactory condition. Pavement preservation consists of “work that is planned and performed to improve or sustain the condition of the transportation facility in a state of good repair”. Implementing a pavement preservation program offers numerous advantages, including— • Life extension of the existing pavement, • Lower treatment costs, • Reduced user costs, • Improved safety for the public and the transportation workforce, • Improved overall network health, • Environmental benefits such as reduced air pollution and noise during construction, and • Improved sustainability. Although these benefits are well-known, they are difficult to quantify. Several variables can affect the cost-effectiveness of the different treatments, such as pavement condition, climate, traffic, and regional availability. Insufficient information and uncertainty regarding treatment performance under specific conditions can deter agencies from adopting a pavement preservation program. To address this gap, the National Center for Asphalt Technology (NCAT) and the Minnesota DOT Road Research Facility (MnROAD) partnered to study the long-term performance of multiple pavement preservation treatments, aiming to determine their life-extending benefits. The results of this study can serve as a guide for agencies to select appropriate treatments that meet their site-specific needs in the most cost-effective manner possible. The most significant outcome of this research is the development of data-driven, easily accessible resources, laying the path for future program implementations.

The goal of this research is to investigate each agencies current design method to discover similarities and differences in the way each agency designs and builds roadways for both low and high volume roads. Each agency was given design specific inputs of common climate, traffic, and existing subgrade soil (from MnROAD) and was asked to develop a design based on current design practice/standards. This paper documented the differences in construction, materials, and expectations on performance to provide and will provide a bases for future agency discussion. The initial survey contained more information that could be covered in this paper. Future goals could include the additional information for other research topics, developing possible test sections, and again to provide a common point of discussion for future efforts. This work also builds off of the efforts started with the NVF34/Nord FOU concept at the 2007 Iceland workshop.

This paper presents the results of a blind test evaluation of various nondestructive testing techniques including well established methods such as chain dragging, rod sounding, and GPR as compared to an emerging ultrasonic array technology in determining the extent of the concrete joint deterioration. Nondestructive testing at two concrete pavement joints at MnROAD was performed and the results were independently evaluated and submitted to MnDOT. Significant discrepancies in subsurface deterioration assessments were observed among these techniques. Forensic evaluation (trenching and coring) were utilized to resolve the discrepancies in test results. It was concluded that the ultrasound array analysis was the only method able to accurately determine the horizontal extent of the deterioration otherwise undetected by the other available nondestructive evaluation methods. Additionally, ultrasonic tomography analysis was able to determine the depth of the deterioration. This makes this emerging technology an attractive alternative to traditional NDT methods for concrete pavement joint assessment. Paper submitted for the Transportation Research Board 92nd Annual Meeting, 13-17 January 2013.

MnROAD, located near Albertville, Minnesota (40 miles northwest of Minneapolis-St. Paul) is one of the most sophisticated, independently operated pavement test facilities of its type in the world. MnROAD has collected data since 1993 on three unique road segments located parallel to Interstate 94. MnROAD data is collected in a number of different methods and processes, which impacts how we store the data (both calculated and raw values). The purpose of this document is to describe what data has been collected, where it is stored for research use, and how to access the data.

From the start of construction on MnROAD in June 1990 to the conclusion of MnROAD’s first ten years of operation in 2004, engineers at MnROAD were busy with a number of core activities: conducting research in pavements, collecting and analyzing data, and developing and maintaining the world’s largest full-scale pavement test track. Many of these activities were recorded in a number of reports published by MnDOT. Though this brief does not account for all of the hundreds of MnDOT reports that mention MnROAD, it will review MnROAD’s objectives in research and characterize the reports dealing with MnROAD’s activities in its first ten years of operation.

Transportation and its supporting infrastructure have significant economic, social, and environmental impacts. Using more sustainable methods to design, construct, and preserve roads will better protect the environment and meet our ongoing needs. Mn/DOT and our partners in government, industry, and academia have been researching and implementing ways to make our roads greener, while maintaining or improving roadway quality.

The objective of this study is to demonstrate the use of fine and coarse taconite aggregate materials in hot mix asphalt, Portland cement concrete, and other pavement applications for both its constructability and field performance over time. This would help create a greater comfort level for the use of taconite aggregate and help promote its use in the state and around the nation. The specific goal of Task F is to perform laboratory tests on taconite aggregates and on pavements made out of taconite aggregates to establish how these materials will be used in the most appropriate manner for long-lasting roadways. Mn/DOT has the laboratory equipment and expertise to do this required material testing.

A field review was done to investigate three roadways that incorporated a strong stone base or Scandinavian design built in central Minnesota (Mn/DOT District-3). These were initially built though a partnership with Mn/DOT and Finland where Gary Niemi (now retired D-3 engineer) visited Finland and brought back these designs to Minnesota in the late 1990’s. The whole idea of a large stone base design is to gain the strength or support for your roadway through the unbound base materials and have a relatively thin asphalt layer that can be milled and recycled at a lower cost while still preserving the underlying base materials. The top asphalt layer is not designed to carry the traffic loadings.

Transportation and its supporting infrastructure have significant economic, social, and environmental impacts. Using more sustainable methods to design, construct, and preserve roads will better protect the environment and meet our ongoing needs. Mn/DOT and our partners in government, industry, and academia have been researching and implementing ways to make our roads greener, while maintaining or improving roadway quality. MnROAD is conducting research on several “green” pavement technologies that reduce environmental impacts, reuse roadway materials, or use recycled materials in pavement applications:

Low temperature cracking occurs when cold weather temperatures cause the upper part of a pavement section to contract, while the pavement’s bottom section is held in place by its granular base and prevented from contracting. To relieve stress, cracks are formed at semi-regular intervals, thus degrading the pavement and reducing riding comfort. Low temperature cracking is the main cause of pavement roughness and reduced service life in northern climates.