Orange barrels on a highway


Minnesota's Cold Weather Road Research Facility

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MnROAD Research Briefs


UltraPerformance of Ultra Thin Bonded Wear Course


This review was part of ongoing research to determine how Bituminous over Concrete (BOC) pavement cracks, and how to reduce or eliminate cracking of the Hot Mix Asphalt (HMA) overlay.








Joint SealingThe Effect of Joint Sealing on the Performance of Thin Whitetopping Sections at MnROAD

(PDF, 516 KB, 5 pages)


To determine the benefits of sealing joints in whitetopping overlays, several test sections were constructed in 2004 at the Minnesota Road Research (MnROAD) facility. After more than seven years of interstate traffic and exposure to the extreme climate of Minnesota, sufficient data now exists that can answer the question of whether sealing or filling thin whitetopping joints has a significant effect on long term whitetopping performance.






2011 Construction Update

(PDF, 725 KB, 2 pages)


This report summarizes the construction of 2011 on the MnROAD facility.







brochure2011 Brochure

(PDF, 1.6 MB, 6 pages)


The new MnROAD Brochure.







geosynthetic materialGeosynthetics Use to Improve Road Performance

(PDF, 1 MB, 2 pages)

Researchers evaluated the pavement performance benefits of using geosynthetics in pavement base and subbase layers, including improved ride quality and reduced cra cking and rutting. Results show that while geotextiles did not perform as expected, geogrids clearly benefit pavement performance.






water systemsGreen Roads

(PDF, 488 KB, 7 pages)


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.







Full Depth ReclamationFull Depth Reclamation


Full Depth Reclamation (FDR) is the process of pulverizing a roadway's flexible pavement section and a portion of its underlying base, and crushing and blending the recovered material to create a uniform base material.








longitudinal jointImproving HMA Longitudinal Joints through Construction, Preventive Maintenance and Repair

(PDF, 270 KB, 4 pages)


The Minnesota Department of Transportation (Mn/DOT) is currently conducting a research project aimed at reducing longitudinal joint (Ljt) deterioration in hot mixed asphalt (HMA) pavements through improved construction techniques, preventive maintenance practices, and repair treatments. Constructing durable HMA pavements, with adequate Ljt performance, has been well documented and extensively researched, however preventive maintenance and repair treatments specific for Ljt have received little attention in the literature.



low temperature cracking examplesLow Temperature Cracking Performance at MnROAD

(PDF, 192 KB, 9 pages)


MnROAD research facility was constructed in part because of it's ability to record information of how pavements react in cold weather. This is an overview of the different pavement cells and their low temperature cracking.



user guideMnROAD Data Release User Guide

(PDF, 353 KB, 2 pages)


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.














mower country bridgeMower Country Bridge Instrumentation

(PDF, 446 KB, 2 pages)


Mower Country's Bridge was in need of repair but while the concrete was setting a flash flood tore away the infrastructural support. MnROAD engineer's helped to rig teh bridge with recording instrumentation to see whether it had set to a safe degree.








ham pavementPavement Noise Research

(PDF, 527 KB, 7 pages)


Noise from highway traffic is an environmental problem in both metropolitan and rural areas. The most significant impact of traffic noise is the annoyance it causes to people and the associated negative effects this annoyance has on the quality of life. In addition to annoyance, traffic noise may also impact health, create difficulty with speech communication, suppress real estate values, and cause the stagnation of economic expansion due to public resistance to expanded highway capacity. To solve the problem of increased urban highway noise, Mn/DOT researchers have set out to find cost-effective pavement types that can reduce the sound at its sources: where the rubber meets the road.





pervious asphaltPervious Concrete

(PDF, 260 KB, 3 pages)


Test cells were constructed at MnROAD to be monitored for drainability to evaluate the possibility of using pervious pavements to mitigate this problem. Other important criteria influencing the performance of pervious concrete in pavements will also be monitored, including mechanical and structural properties, surface characteristics, noise, and durability.








flattening asphaltPorous Asphalt Pavement Performance in a Cold Climate

(PDF, 123 KB, 2 pages)


Porous Asphalt Pavement is an emerging technology in the United States. It consists of standard bituminous asphalt with reduced fine particles and high (20 %) void content. The high porosity of the mix allows water to penetrate directly through the pavement surface. Beneath the pavement, a uniformly-graded stone bed allows water storage and slow infiltration into the subgrade soils. Filter fabric installed between the stone bed and the subgrade prevents migration of fine particles upward and contamination of the stone storage layer.





damage to a road due to an implement of husbandryThe Effects of Implements of Husbandry "Farm Equipment" on Pavement Performance

(PDF, 641 KB, 2 pages)


For this study an entirely new road was built at MnROAD called the "farm loop." The test roadway, constructed in 2007, is typical of many rural, low-volume roads. The roadway was constructed in two sections: one section representing a typical 7-ton road in Minnesota and the other representing a typical 10-ton road.










sounds absorption systemSurface Characteristics of Flexible Pavement

(PDF, 356 KB, 2 pages)


In order to design durable pavements with the optimal characteristics for noise, safety and ride, the interaction among surface characteristics and their relationship to mixture type must be better understood.








concrete pavingSurface Characteristics of New PCC

(PDF, 466 KB, 2 pages)


Pavements are substantially affected by joints, while the continuously reinforced concrete pavements are affected by the intermittent structural cracks. These features in conjunction with other distress and surface conditions affect performance characteristics of the pavements. This study focuses on fundamental surface characteristics of new Portland Concrete Cement (PCC) pavements, how they interact and how they change over time.






diamond ground concrete Surface Characterstics of Rehabilitated Concrete

(PDF, 365 KB, 2 pages)


Diamond grinding is a process to correct defective surface textures and poor ride quality in concrete pavements. In addition to being used as a rehabilitation tool, some agencies use diamond grinding as the initial pavement surface texture. It can also have a positive effect on reducing tire-pavement noise. The growing awareness of noise as an important pavement surface parameter resulted in an increase in the amount of research focused on the study of roadway pavement surfaces, the noise they produce, and in the development of quieter pavement surfaces.



measuring temperature of asphaltWarm Mix Asphalt (WMA)

(PDF, 556 KB, 2 pages)


Warm mix asphalt (WMA) is a general term describing the use of any additive or technology that allows for lower asphalt plant mixing temperatures. Developed in Europe, WMA was brought to the United States in 2004 and has since gained widespread use around the country. Environmental benefits experienced with WMA include reduced emissions, fumes, and odors. With a cooler work environment enabled by WMA technology, reduced production temperatures add up to energy savings. The Minnesota Department of Transportation (MnDOT) saw the promise in this technology, especially the anticipated benefit of reduced low temperature and reflective cracking because of the reduced binder aging at the plant.




cracked concreteWhitetopping: Thin and Ultra-thin Concrete Overlays

(PDF, 209 KB, 4 pages)


Thin and ultra-thin concrete overlays (also known as whitetoppings) are a pavement rehabilitation option that has been increasing in popularity in the U.S. over the past 15 years. One area of deficiency in the use of ultra-thin and thin concrete overlays is the lack of a rational design method. While several local (1,2) and industry (3,4) design methods have been formulated, few are based on mechanistic-empirical research born out of actual field performance. Fortunately, the Minnesota Road Research Project (MnROAD) has contributed significantly to the understanding of the field performance of thin and ultra-thin concrete overlays.