LRRB 2004 Research Projects

808
Reclaiming Pavement - Low Volume Roads

This project will specifically look at stabilized and unstabilized full depth reclamation (FDR), cold in place recycling (CIR), and mill/overlay (M&O). Currently constructed roads will be evaluated for performance (rutting, raveling, crack count and severity), pavement type/strength, condition of pavement before rehabilitation, construction and maintenance costs. The resulting report will summarize the cost and performance of the rehabilitation techniques used. This information will then be condensed into a guide that can be used in the future as a resource for selection characteristics and performance. Contact: Brad C Wentz, Becker County Engineer, 218-847-4463
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809
Research Tracking for Local Roads

Under this project the Road Research Section of the Materials Office, will enhance a tracking system they developed that will provide a place for the champion for a research project to document the project name, purpose, locations and comments for each test section developed. Others can then build on this information as the research progresses or as information from other test sections or performance or materials testing from other databases becomes available. The system will be housed at Mn/DOT, maintained by the Materials Office, and linked to the LRRB web page. The Road Research Section staff will provide local agencies with phone support and assistance to get their data into the system. Contact: Lou Tasa, District 2 State Aid Engineer, 218-755-3808
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810
Coal Ash Utilization in Gravel and Paved Roads

The primary objective of this study is to assess the effectiveness and environmental suitability of incorporating fly ash stabilization in local roads in Minnesota. It is anticipated the research will also serve as the first phase of a broader objective of increasing acceptability and use of fly ash stabilization in Minnesota. Contact: John A Siekmeier, Mn/ROAD Research, 651-779-5299
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811
Match for Snow Plow Routing Study

This project will provide match funding for a study to refine the evaluation process utilized by OSM & Associates, Inc., to document the process, and provide computer software and training manuals for maintenance personnel to be able to perform these analyses and evaluations for any maintenance area or maintenance subarea in the state or county. A final part of this project will be to deliver sufficient "train the trainer" sessions to enable Mn/DOT personnel to perform and train others to perform these analyses and evaluations. Contact: Benjamin Zwart, Office of Maintenance Engineer, 651-282-5434
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812
Resilient Modulus & Strength of Base Course with Recycled Asphalt

The objective of this study is to investigate the criteria for using these materials with respect to resilient modulus and strength of laboratory specimens. Resilient modulus and shear strength will be measured at different moisture contents and densities. Moduli estimated from the nondestructive technique involving the bender element will be compared to available field measurements. Contact: Shongtao Dai, Mn/ROAD Research, 651-779-5218
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813
Human-Centered Interventions Toward Zero Deaths in Rural MN...

This project will support the development of a human-centered intervention to reduce the mortalities from the high rural crash rate in Minnesota by investigating the psychological and social factors that may predispose rural drivers to drive less safely, including disregard for current traffic laws (e.g., intersection sign compliance) and safety intervention programs (e.g., seat belt compliance). This research will be done with surveys, based on standardized questionnaires and a simulator experiment. The results of this project will support effective countermeasures that have a form and target consistent with the psychosocial nature of rural crashes. Contact: Richard C Larson, Mille Lacs County Engineer, 320-983-8201
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814
Implications of State Aid Cuts for Local Road Funding

This study will examine the implications and policy options that follow from changes in the state-local fiscal relationship. Four potential outcomes could result from cuts in state general-purpose aid: road budgets could be restored with state road aid, local taxes could be increased to compensate for the lost aid, local governments could do a better job providing service with existing resources, or fewer local road services could be produced. Each outcome has implications for taxpayers, and each will require an explicit or implicit policy decision. Contact: Julie Skallman, Transportation Division Engineer, 651-296-9872
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815
Calibration of the 2002 AASHTO Pavement Design Guide for MN PCC/HMA Pavements

This study will include development of guidelines for major input parameters (traffic, material properties, subgrade characterization), comprehensive sensitivity analysis, comparison against MnPAVE and current design standards, comparison of predicted pavement performance with observed performance of pavements in Minnesota, and recalibration of performance prediction models for local conditions. Contact: David A Van Deusen, Mn/ROAD Research, 651-779-5514
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816
Low Temperature Cracking of Flexible Pavement Due to Thermal Fatigue and Combined Effects Temp/Load

To address low-temperature cracking, laboratory instruments were developed during the Strategic Highway Research Program (SHRP) effort to investigate the low temperature behavior of asphalt binders. The funding provided under this project will be used towards the purchase of this equipment and to provide training for the University's pavement laboratory staff. The equipment will improve and expand the experimental capabilities of the laboratory to perform advanced material characterization related to low temperature cracking in asphalt pavements and further support the University's ability to attract and perform other pavement research activities. Contact: Shongtao Dai, Mn/ROAD Research, 651-779-5218
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817
Determination of Optimum Time for the Application of Surface Treatments to Asphalt Concrete Pavements

The objective of this study is to provide a better understanding of how surface treatments seal and protect the existing pavement from further aging and deterioration from cracking (low temperature, fatigue) and to identify the optimum time for the application of these treatments. This requires a reasonable understanding of the very complex aging mechanism in asphalt materials as well as the effect of aging on their fracture resistance. It is expected this limited research will provide preliminary guidelines in terms of type of treatment and timing of the application. Contact: Chris Cochran, East Metro Surveys, 651-779-5518
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819
Cell 26 Reconstruction at Mn/ROAD

To provide partial funding for reconstruction of Cell 31 at Mn/ROAD facility with a superpve mix incorporating newly mined taconite aggregate over a Class 6 base. Mn/DOT and DNR are partners in project assisting with construction and materials costs. The taconite materials will be provided at no cost to MnDOT by the DNR working with private industry. MnDOT will assume the cost of present base removal and replacement plus the cost of mixing, hauling and placement and the costs for associated research instrumentation of the reconstructed cell. Contact: Wayne Fingalson, Wright Co. Hwy Dept. Engineer, 763-682-7388
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821
Assess Life-Cycle Costs and Roadway Surfacing Impacts of Increasing Roadway Construction Standards to Accommodate Greater Axle Loads on Local Residential Streets in Minnesota Cities

The primary focus of this study is to compare the current roadway construction and maintenance costs (life-cycle costs) that city budgets must address under the 6 to 7 ton construction standard to the life-cycle costs of a 9 ton construction standard. Life-cycle costs are those costs of initial construction, maintenance i.e., patching, milling, overlays, and reconstruction of pavement, curb and gutter, including additional grading items. The time period for life-cycle costs is estimated at 35 years. The objective of this study is to provide a final report that summarizes the comparison of the life-cycle costs for the two construction standards described above. This document will be used to provide a basis for budgets on future projects and pavement management plans. Contact: Tom Mathisen, City of Crystal Engineer, 763-531-1160
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LRRB CY 05 Research Program

822
Crack Sealing and Filling Performance

This research will utilize performance-based laboratory tests for the selection of crack sealants. These tests would relate performance to high and low pavement temperatures similar to the Performance-Graded (PG) Asphalt Binder tests. In addition, rout configuration and installation practices will be investigated to improve crack sealing performance through field evaluations. The goal of this project would be to provide local agency personnel with a Best Practices Manual for crack sealing and crack filling that would improve sealant selection and installation practices. Ultimately this will result in better sealant performance and, in return, decreased maintenance dollars and longer pavement life. If funded, this project would build on information developed from a crack sealing consortium that 26 other states and Canada are participating in. It would also tie into INV 770, Repair of Rubberized Crack Filler/Joint Filler (2002), and INV 802, Performance of Pavement Crack Sealants Beneath Bituminous Overlays (2003). Contact: John Siekmeier, Mn/DOT - Materials & Road Research, Lab651/779-5299 or Tom Struve, City of Eagan, 651/675-5300.
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823
The Road to a Thoughtful Street Tree Master Plan

Many, if not most, urban forestry successes and failures begin at the planning stage. The intent of this design manual is to replace as many of the subjective decisions made during street tree design and plant selection with objective criteria. The manual will be developed and formatted to assist communities and planners to not only select the best trees for their available planting sites (if the sites can support trees), but to use specific principles of street tree design to most effectively create public green spaces, positively affect traffic patterns, and create healthy living spaces. The US Forest Service has provided $5,000 in seed money to get the project going. Another $30,450 is needed to develop the manual and get it printed. The manual will have applications outside of MN by replacing the tree specific information. Both above and below ground utilities will be addressed. Contact: Daniel Gullickson, Mn/DOT/ Environmental Services, 651/284-3763 or Thomas Pagel, Grand Rapids City Engineer, 218/326-7626.
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824
Development of Improved Proof Rolling Methods for Roadway Embankment Construction

Test Rolling has been used to determine if the underlying subgrade of a roadway embankment being built has been adequately compacted. In the test, the amount of depression or rutting that occurs while a loaded cart vehicle is towed across an area of an embankment under construction is monitored. If the depression/rutting depth exceed the specified limits, problem areas that need reworking are identified. Phase I of the proposed research will concentrate on investigating the effect of cart weight and tire width, as well as subgrade properties, layering and thickness, on the depression/rutting depth. Analytic and numerical models will be considered that account for subgrade strength and deformability. The most important parameters will be identified.

The results of the investigation will allow assessing the range and sensitivity of the test to varying subgrade conditions, and validity of the "fits-all" approach presently in use. In Phase II of the project, the predictions will be compared with results of physical tests conducted by Mn/DOT, with U of M assistance, at selected sites. Based on the comparison and additional computations and lab testing if needed, recommendations for use of test rolling and possible modifications will be formulated. Contact: Richard Heilman, Isanti County/Engineer, 763/689-1870 or Tim Andersen, Mn/ROAD Operations, 651/779-5609.
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825
Performance Monitoring of Olmsted CR 117 and 104 and Aggregate Base Material Update

INV 767, Investigation of Flexible Pavement Performance in Relation to Aggregate Base and Asphalt Mixture Low-temp Characteristics was funded jointly in 2000 by LRRB and Mn/DOT to evaluate the constructability of three aggregate base types and two asphalt mixtures to:

Evaluate the properties (permeability, strength, and resilient modulus) of these material types in relation to freeze-thaw cycles

Evaluate the low-temperature cracking resistance of the asphalt binders to saw-and-seal construction.

The objective of this proposal is to perform a follow-up performance monitoring survey over a 5 year period, since no distress was developed during the initial study. Performance monitoring tests would include traffic counts, FWD, GPR, and rutting surveys at various times of the year to measure the effects of temperature and time on the measured results. The research would incorporate the results of these above-mentioned field tests into MnPAVE. In addition, a member of the Norwegian delegation currently visiting Mn/DOT (Karl Melby) has indicated a willingness to cooperate on an international effort to increase Minnesota's understanding of the spring-thaw performance of open-graded base materials. Contact: Michael Sheehan, Olmsted County Engineer, 507/285-8231.
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826
Appropriate Use of RAP

Local agencies have seen early failures in RAP (recycled asphalt pavement) mixtures such as raveling and cracking. A survey will be sent out to local agencies and a select matrix of pavements that have shown earlier than expected failures will be analyzed. Recommendations from the analysis will be given on the appropriate use and quantity of RAP used in Minnesota HMA pavements. Contact: John Brunkhorst, McLeod County Engineer, 800/350-3156 or David Linell, Mn/DOT/Materials, 651/779-5614.
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827
Investigation of Winter Pavement Tenting

Deicing salts used in the winter for ice control on pavements may tend to seep through the cracks in pavements and saturate the aggregate base with a brine solution. Cracks are open widest in the winter and since these brine solutions attract moisture, it is proposed to investigate any effects of added heaving movement at crack locations. Results of the project will focus on defining winter crack conditions and be used for maintenance decisions regarding crack sealing or deicing protocol. Information on the susceptibility of pavement types to crack tenting will be made available for designers. Contact: Gary Bruggeman, Steele County Highway Department, 507/444-7671.
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828
Local Road Materials Properties and Calibration of MnPAVE

The existing version of MnPAVE was calibrated to match the existing R-Value design procedure and typical state highway pavement structures. Estimates of the seasonal variation in soil and aggregate base material properties were based primarily on studies done at a single location. This study will produce a version of MnPAVE that focuses on local road structures and seasonal variations in material properties, specifically during the spring thaw period. MnPAVE will also be calibrated to local road performance data. The results of this research will provide financial savings due to improved reliability of pavement designs and a user-friendly mechanistic-empirical pavement design program calibrated for local roads. Contact: Richard Larson, Mille Lacs County Engineer, 320/983-8201.
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829
Validation of DCP and LWD Moisture Specifications for Granular Material

There is currently no accepted protocol to measure the in situ stiffness, strength, and moisture during construction and then relate these measured values to the seasonal values that are estimated and used during mechanistic-empirical pavement design. The proposed project will result in a laboratory validation that quantifies the effects of moisture, density, and grading on the DCP strength and LWD stiffness of granular materials. The DCP and LWD precision will also be quantified under well-controlled laboratory conditions. The results from this project can be immediately incorporated into the existing national NCHRP and MnPAVE pavement design software in order to further encourage implementation of mechanistic-empirical pavement design and mechanistic QC/QA field testing. Local engineers, pavement design consultants, and geotechnical testing companies are currently using in situ testing tools such as the DCP. Contact: Larry Berkland, Asst. Steel County Engineer, 507/444-7672.
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830
Evaluating Roadway Subsurface Drainage Practices

In this three part study automated drain outflow instruments to monitor cumulative drainage outflow at roadway sites selected in a statistically-based monitoring design will be installed. These drainage outflows will be analyzed with statistical procedures to asses the difference between drainage treatments. The effects to be evaluated include:
1). The difference in drainage from edge-drains versus centerline drains
2). The difference in drainage from low points in the roadway versus relatively higher elevations
3). The difference in drainage from drains embedded in base containing conventional amounts of crushed concrete, versus those in base containing a larger than conventional amount of crushed concrete. A test of the electromagnetic induction method for measuring moisture content of roadway base and subgrade materials will also be performed. If the method provides reasonable accuracy, it will then be used to non-invasively measure the moisture content profiles along highway transects to help to assess the benefits of drainage on the moisture balance in the base and sub grade material of roadways. Contact: Stephen Schnieder, Nobles County/Engineer, 507/376-3109 or Ruth Roberson, Mn/DOT/ Materials & Road Research, 651/779-5214.
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831
Investigation of Stripping in MN Class7 (RAP) and Full Depth Reclamation Base Material

The proposed research will evaluate local recycled asphalt pavement (RAP) for their moisture sensitivity performance and will promote using local RAP in Minnesota's pavement sections to reduce material costs. Expected results from this research will improve current specifications of Class 7 and full depth reclamation base material and will improve the pavement design process by providing more accurate information on the performance of RAP as a base component. The results of this research will also confirm if RAP as a base material is responsible for performance problems due to consolidation concerns as a result of moisture-related damage. The research will also test if potential contamination to ground water is likely to occur as a result of using RAP in base materials. Contact: Milton Alm, Norman County/Engineer, 218/784-7126 or Tim Andersen, Mn/ROAD Operations, 651/779-5609.
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832
Volume Warrants for Right Turn Lanes

Turning lanes reduce crashes as crash rate comparisons demonstrate; yet, warrants or guidelines are not clearly established for a sufficiently broad range of conditions. It is more so for right turn lanes. The goals of this research are to determine when a right turn lane is needed, when treatments by themselves are adequate, and what volume threshold requires neither treatments nor turn lanes. This in turn will allow for better volume warrants for right turn lanes and eventually lead to more cost-effective highway safety plans and programs. Both rural and urban roads would be examined in this study. In addition, the study may include looking at roads that have left hand turn lanes. Contact: Brian Gage, Mn/DOT – OIM, 651/ 205-4427.
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833
Design Tool for Controlling Runoff and Sediment from Highway Construction

Control of runoff and sediment from highway construction sites is an important component of the transportation infrastructure. Numerous experimental studies have been or are being supported by Mn/DOT and LRRB to understand erosion processes and to implement best erosion/sediment control practices. Nonetheless, extrapolating results from these studies to the myriad of construction conditions in Minnesota is difficult. It is best accomplished by using a theoretical framework that links together the many factors influencing erosion and sediment transport. An important first step in linking key processes was the development of the WATER (Watershed Assessment Tool for Environmental Risk) simulation tool. This model simulates the runoff and erosion for a single roadside construction unit and is limited to on-site erosion control practices. The proposed project expands the WATER model by including algorithms for off-site sediment control practices (such as detention ponds), by linking together multiple construction units and other land uses to simulate the response of watersheds, and by improving user friendliness with the use of spatial data sets. These additions are critically important in developing a model that is useful to erosion/sediment control practitioners. Contact: Leo Holm, Mn/DOT/ Engineering Services, 651/284-3766.
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834
Assessment of Storm Water Management Practices on the Water Quality of Runoff

In an effort to treat runoff and remove suspended and dissolved contaminants, many technologies have been developed. Various levels of government will spend millions of dollars on implementation of storm water treatment practices over the next five years. These include grassed swales, filter strips, detention ponds, grit chambers, infiltration trenches, and sand filters. Guidance is needed for monitoring, and a storm water treatment monitoring protocol will be developed under funding from the Minnesota Pollution Control Agency (MPCA). The objective of this proposal is to apply and test the monitoring protocol on three Mn/DOT or LRRB storm water treatment sites, and assess the pollutant removal effectiveness at each site. The proposed project would improve the effectiveness of storm water treatment evaluation and implementation through detailed monitoring and assessment of performance. It would also assure that the type of sites owned by Mn/DOT or LRRB are fully integrated into the monitoring protocol. Contact: Jon Haukaas, Fridley Public Works Director, 763/572-3550.
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835
Best Use of Cone Penetration Testing

Over the past few years, Mn/DOT has been using cone penetration testing (CPT), which has several advantages over conventional drilling: (1) fewer personnel required for operation, (2) increased production, and (3) essentially continuous and real time data. Mn/DOT has gained a level of expertise through past work with the CPT, but would like to optimize the technology and improve capabilities of subgrade characterization. The development of correlations between CPT tip stress and resilient modulus has direct application to pavement design. Quick and repeatable testing afforded with the digital instrumentation in the CPT system can replace traditional solid stem augering and provide assessment of soil stiffness and strength. The objective of this study is to develop correlations between design parameters such as resilient modulus and CPT readings. Contact: Dave Shanahan, Wabasha County Engineer, 651/565-3366 or Jeff Gebhard, Office of Materials, 651/779-5596.
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836
Design Procedures for Bitumious Stabilized Road Surfaces for Low Volume Roads

Many pavements in the county road system in the State of Minnesota consist of unpaved aggregate surfaces. It is often the duty of the county engineer to make determinations regarding the design of such roads for a specific need, such as for weight restrictions. One method used by Blue Earth County, Chisago County, and others is essentially to create a bituminous-stabilized layer of aggregate in the top several inches of an aggregate-surfaced roadway by mix-in-place methods. A clear need, however, is a design procedure to provide county engineers and their staffs with technical backing for the designs selected.

For example, if the county desires to design an unpaved road to a seven-ton rating, currently there is no clear method to determine the required thickness of the aggregate layer and the depth of in place bituminous stabilization to achieve the required strength and support. This project will develop a simple design procedure, consistent with other, nationally recognized design procedures for low-volume roads, that will allow counties to determine the best structure for a given support requirement. The procedure will require parameters such as soil type, moisture content and drainage characteristics, axle weights to be supported, and will consider the life expectancy of the pavement structure. By performing the simple soils and aggregate tests in the new design procedure, counties could eliminate unnecessary overdesign and potentially save money, since it is estimated that the average cost of one mile of Class 5 material is about $2,500 per lane mile. Contact: Alan Forsberg, Blue Earth County/Engineer, 507/625-3281 or Thomas Wood, Mn/DOT, 651/779-5530.
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837
MnROAD Reconstruction of Low Volume Roads

MnROAD's initial test sections were opened to traffic in 1994. Since that time some test cells on the low volume road have been reconstructed. Currently test cells 24-25, 27-30, may need work in 2005 and will need work in 2006 when the larger reconstruction is planned. MnROAD is developing a technical committee to work on the PCC, HMA needs for the future reconstruction. This project will evaluate the cost, constructability, and performance of future MnROAD test cells. Currently MnROAD may need reconstruction in 2005 (depending on what happens in Spring of 2005) and will need reconstruction in 2006 when the majority of the HMA and some of the PCC will be reconstructed. Some of the current proposed study areas could be done this year if a test section fails in Spring 2005: 1) Taconite SMA or High Volume Superpave, 2) Demonstrate Spring Load Restriction Needs, 3) Scandinavian Road Design. Contact: Dave Robley, Douglas County/Engineer, 320/ 763-6001.
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LRRB CY 06 Research Program

838
Paving Fabric for Isolating Existing and Overlay Bituminous Pavement

Bituminous pavements require major seasonal maintenance for both thermal and distress crack repairs. Reconstruction, structural upgrades or maintenance overlays generally include intensive and expensive milling or reclaim operations to reduce/retard the effects of existing cracking or crack sealants. Traffic levels and weights on the Trunk Highway and County State Aid Highway systems continue to increase. New State and State Aid studies propose to upgrade thousand of miles from 7-ton to 9-ton to 10-ton routes. Less expensive alternatives to isolate existing problems and retain strength and usability of existing roadways are needed. The objective of this project is to provide photographic and narrative results and recommendations on the use of paving fabrics for reflective cracking isolating and pavement strength enhancement. Contact: Lou Tasa-State Aid District 2, 218-755-3808
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839
Warrants for Roundabouts

Modern roundabouts have gained recognition as a viable intersection alternative across the country for almost a decade. Roundabouts provide safety, operational, and environmental benefits that traditional uncontrolled, stop and signal controlled intersections often can not provide. Roundabouts also offer another alternative in the intersection toolbox for planners and engineers. This research will advance Mn/DOT and local government agencies another step closer to including roundabouts as standard intersection operations and safety improvement alternative, rather than the exception. Contact: Roger Gustafson, Engineer/Public Works Director 952-466-5206
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840
Performance of Pg 52-34 Oil on Local Roads

Currently, Mn/DOT PG binder guideline recommends that PG 58-28, PG58-34 and PG64-28 be used for pavements with ESALs less than 3 million. The guideline does not make any recommendations of PG binder usage for low volume roads, such as roads with 150,000 ESALs. Some local agencies have had success using PG 52-34 for low volume road construction. Research is needed to determine at which traffic level PG52-34 can be used as an effective asphalt grade without being susceptible to rutting. Contact: Brian Noetzelman, 320/634-4561
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841
Long-Term Maintenance Effects on Hot Mix Asphalt Pavements Caused By Centerline, Edge Line, Shoulders, and Stop Bar Rumble Strips

The use of ground and rolled in rumble strips both along the centerline and on the shoulder of Hot Mix Asphalt (HMA) paved roadways has greatly increased in recent years. The presence of rumble strips in HMA has not been studied to determine if they shorten the life of roadway. This research will try to determine if there are any detrimental effects to HMA roadways caused by the rumble strips. If this research does find that rumble strips do shorten the life HMA roadways the research project will then look at methods to lessen the damage to the HMA roadways. Contact: Dennis Luebbe, 507-332-6110
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842
Best Practices for Dust Control on Aggregate Surfaced Roads

With more traffic on aggregate surfaced roads there is a need for dust control. As people move from a city to a rural area they may have an expectation of a dust free environment. To keep dust down, various chemicals are used. The research would include field tests of the effectiveness of dust control products. This would include application rates, costs, equipment needed, etc. Several of the most commonly used products could be tested and compared on aggregate surfaced roads. Contact: John P McDonald, 507-526-3291
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843
Predicting the Occurrence of Bumps in Overlays

Based on the previous work conducted under LRRB INV 802, some specific mechanisms were identified that seem to be common to many overlay projects that develop these bumps. The primary objective of this project is to develop improved methods for predicting and minimizing the probability of these bumps occurring, and for mitigation of the problem if it does occur. Contact: John Brunkhorst, 320-864-1302
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844
Update of Vehicle Classification for County Road Pavement Design

The primary objective of this proposed research is to update the vehicle classification and distribution that counties use when designing pavement structures to characterize the traffic more accurately. Since the 1977 traffic distribution, which was revised in 1997, there has been a continued shift in vehicle distribution, especially in the rural, agricultural areas of the state. For example, more farmers have acquired tractor semi-trailers to transport their grain to be processed. With the proposed 10-ton intercounty road network, it will be important to distinguish between functional classification when estimating vehicle distributions. This project will allow local agencies to customize a spreadsheet that will more accurately reflect vehicle classification in their area. Contact: Tim Stahl, 507-847-2525
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845
Documentation of Crash Characteristics and Safety Strategies at Horizontal Curves on Rural Highways

It has been reported that 40 percent of fatal crashes in Minnesota involved road departure crashes. Of these, 40 percent appear to have occurred on horizontal curves. The proposed research is intended to develop an understanding of the crash differences between tangent sections and horizontal curves specific to Minnesota’s rural two-lane highways. With an better understanding of the crash problem on Minnesota’s horizontal curves, Mn/DOT and its safety partners can be more effective at addressing the State’s crash problem, accelerating the Towards Zeros Deaths initiative. Contact: Nathan Richman, 507-835-0660
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846
Hydraulic, Mechanical, and Leaching Characteristics of Recycled Materials

The study aims at characterizing water retention, hydraulic conductivity, shear strength, resilient modulus, and leaching characteristics of several recycled materials used in roadbed construction. These materials include reclaimed concrete, recycled asphalt pavement (type 1 and 2), asphalt shingles, shredded tires, fly ash, and municipal solid waste (MSW) bottom ash. All properties will be measured on pure and mixtures containing recyclable materials. Hydraulic, mechanical, and leaching characteristics will then be used to delineate the suitability of recycled materials in pavement construction. Contact: Ruth Roberson, 651-779-5214
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847
Use of Fly Ash for Reconstruction of Bituminous Roads

This project builds off previous LRRB investigations that examined the feasibility of using fly ash in stabilizing soils and the potential environmental impacts. In this project, the gravel equivalency, life expectancy, and potential environmental impacts of fly ash stabilized recycled pavement materials will be assessed through large-scale laboratory experiments, small-scale laboratory tests typically used for design and analysis, and continued monitoring of two existing instrumented roads where fly ash stabilization has been conducted and extensively documented. Data obtained from the laboratory tests and the lysimeters will be compared with predictions from the models STUWMPP and WiscLEACH, which were specifically designed to assess potential groundwater impacts from projects where industrial byproducts are used in construction. Results of the study will have a direct impact on the ability to design and evaluate bituminous roads and streets in Minnesota where fly ash is used for in situ base stabilization. Contact: Fred Salsbury, 507-835-9700
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848
Warning Efficacy of Active Passive Warnings for Unsignalized Intersection and Mid-Block Pedestrian Cross-Walks

The effectiveness of active warnings has received surface transportation research attention in relation to pedestrian crosswalks, advance warnings at signalized intersections, and railroad crossings. Results show that, relative to passive warnings, active warnings at railroad crossings, and in advance of signalized intersections, clearly are more effective. In contrast, results regarding the relative warning effectiveness of active versus passive pedestrian cross-walk warnings are mixed. Given that the cost of active cross-walk warnings is substantially higher, relative to passive warnings, further research is needed to: (1) ascertain the comparative warning effectiveness of active versus passive pedestrian cross-walk warnings; and (2) explore low-cost alternative designs for pedestrian cross-walk warnings. This project will carry out: (1) a literature review of research findings relevant to cross-walk warning systems; (2) a field study of the relative warning efficacy of active versus passive warnings at selected pedestrian cross-walks; and (3) a design analysis of low-cost alternatives for pedestrian cross-walk warnings. Contact: Deb Bloom, 651-792-7000
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849
Study of Environmental Effects of De-Icing Salt on Water Quality in Minnesota

The use of sodium chloride as a de-icing chemical has increased dramatically in the northern areas of the United States over the last 50 years. The leading states in highway salt use in the US are Minnesota, Michigan, New York, Ohio, and Pennsylvania (Novotny, 2003). This salt eventually finds its way into lakes, rivers and groundwater. The accumulation of sodium chloride in lakes, rivers and soil can cause concentrations of chloride that are toxic to the environment. The objective of this proposal is to assemble the existing data on the use of salt in every form and application (i.e. from the de-icing salt to water softener salt), and on the salinity/sodium chloride concentrations measured in rivers, streams, lakes, and groundwater in Minnesota, especially in the Twin Cities area. Contact: Wayne Sandberg, 651-430-4339
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850
Mechanistic Modeling of Dynamic Cone Penetrometer Test

The dynamic cone penetrometer (DCP) is currently being implemented within Mn/DOT as an important tool for evaluating the condition of soil and aggregate bases. A recently developed guide – The 2002 Pavement Design Guide for New and Rehabilitated Pavement Structures – identifies the results of DCP testing as possible design input through the characterization of unbound materials. However, the Guide requires conversion of results from DCP measurements into the resilient modulus, and the empirical relationship provided by the Guide is not very reliable. The objective of this research is to develop a theoretically sound and practical mechanistic model of the DCP test which will provide correlation of DCP test results with the results from other tests of unbound materials. Contact: Lee Amundson, 507-694-1464
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851
Allowable Axle Loads on Pavements (Subgrade Analysis)

Deflection testing and analysis is routinely used to evaluate the spring load capacity of pavements, and to design structural overlays. The current process used by MnDOT and implemented into the computer program TONN is not very reliable. The program underestimates the allowable axle load for soft clay subgrades and may overestimate it for stiff sand or granular subgrades. The objective of this study is to upgrade the TONN program. The final product of this study will be an analysis process that results in an allowable axle load and a functional stand alone software package that Mn/DOT and the cities and counties could use on their own, or provide to firms hired to do deflection testing. Contact: Maureen R Jensen, 651-779-5507
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852
Subsurface Drainage Manual for Pavements in Mn

Subsurface drainage removes excess moisture from the base course and the subgrade of highways and thereby increases the overall strength of the pavement structure. Research has shown quite conclusively that effective subsurface drainage provides cost-effective benefits in terms of pavement maintenance and replacement costs. The objective of the proposed project is to develop a design and maintenance manual for pavement subsurface drainage systems in Minnesota. The manual is intended for engineers and managers involved in pavement design, construction, and maintenance decisions. LRRB is requesting the Research Implementation Committee to oversee. Contact: Dan Sauve, 218-694-6132
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853
Development of Flexural Vibration Inspection Equipment and Techniques to Rapidly Assess the Structural Health of Rural Bridge Systems: Phase II

This proposal supplements and continues a UMD NATSRL project, Development of Flexural Vibration Inspection Techniques to Rapidly Assess the Structural Health of Rural Bridge Systems by expanding the bridge type to include dowel laminated bridges and by designing and fabricating an automated testing system. These bridges offer new challenges to vibration techniques because they are considered more of a plate structure than a beam structure, with structural members in both the span and cross-span direction. Contact: Chris Morris, 218-625-3869
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854
Pavement Performance/Failure under Overweight Farm Loads (Pooled Fund Study)

The objectives of this study are to determine the pavement response under various types of agricultural equipment (including the impacts of different tires and additional axles) and to compare this response to that under a typical 5-axle semi tractor-trailer. This may be accomplished by constructing new instrumented test sections at MnROAD and/or to retrofit instrumentation into the existing test sections. The final scope and work plan for the study will be developed by the participating agencies. Contact: Richard B Kjonaas, 651-296-9875
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855
A Property-Based Specification for Coarse Aggregate in Pavement Applications

Current MN DOT coarse aggregate specification for concrete and bituminous mixes dates back to 1930’s and has been updated as more knowledge has become available. The proposed study will develop a set of restructured coarse aggregate specifications that are based on aggregate properties as related to the performance of asphalt and concrete mixes in pavement applications and availability at construction sites. Contact: Gary Bruggeman, 507-444-7671
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856
Investigation of In-Place Asphalt Film Thickness and Performance of Minnesota Hot Mix Asphalt Mixtures

The successful design of hot mix asphalt (HMA) mixtures should consider mitigating rutting, thermal cracking, fatigue cracking and be durable. A loss in durability often manifests itself as fatigue or thermal cracking, but is generally associated with asphalt aging and/or film thickness. The Minnesota DOT currently uses voids in the mineral aggregate (VMA) as a volumetric criteria to ensure durable HMA in the design and construction process. VMA is simply the air and the non-absorbed asphalt by volume of an HMA. One concept that a limited number of owner agencies specify is film thickness. One of the major benefits of using film thickness as established by Campen (1957) over that of VMA is that the calculation recognizes varying gradations, e.g. fine versus coarse, and the corresponding surface areas. Contact: John A Garrity, 651-779-5577
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857
A Report and Analysis of Effects of Seasonal and Climatic Changes on Ride Quality As Observed In MnROAD High and Low Volume Roads

The objective of this study is to evaluate contribution of frost heave on seasonal and long term changes in ride quality of roads in Minnesota using pin elevation measurements and pavement performance data from the MnROAD test. The effect of various design features on mitigation of the climatic effects will be also evaluated. This will permit development of guidelines for better timing of ride quality measurements, guidelines for selection of the pavement design features mitigating the effect of frost heave on ride quality deterioration, and improvement of the 2002 Design Guide site factor for the Minnesota conditions. Contact: Ben Worel, 651-779-5522
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858
Crack and Concrete Deck Sealant Performance

Mn/DOT has been using, to a limited extent, crack and concrete sealants as a preventative measure to reduce the likelihood of reinforcement corrosion. As Mn/DOT prepares to expand the usage of sealants as a preventative measure, a state-of-the-art report is needed for guidance. The purpose of this project is to develop such a report which will document previous investigations on the effectiveness of the current products used including silane, siloxane, methyl-methacrylates, epoxies and urethanes. The report will also consider issues which have not been addressed in previous research, such as the effectiveness of sealants upon reapplication. Contact: Gary D Peterson, 651-747-2107
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860
Compaction Specifications for Unbound Materials

This research is to develop Standard Test Methods for quality control and quality assurance testing utilizing the dynamic cone penetrometer (DCP), light weight deflectometers (LWD), and soil stiffness gauge (SSG). The research will also develop draft specifications for the placement subgrade materials in a highway embankment, and for placement of granular materials, including granular fills, subbase materials, and base materials that utilize these test methods. This work will build on the work currently underway in LRRB Investigation 829 “Validation of DCP and LWD Moisture Specifications for Granular Materials.” Contact: Larry Berkland, 507-444-7672
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861
Best Management Practices for Pavement Preservation of Hot Mix Asphalt

With the advent of new Hot Mix Asphalt (HMA) technology in the last ten years the question about how to best manage the new pavements to yield the maximum useable life has been asked numerous times. No one has determined if these pavements need to have Pavement Preventive Maintenance (PPM) treatments applied to them to yield the most cost effective life. This research will attempt to determine if and when the new types of HMA need to receive PPM treatments. The second part of the research project will develop recommend practices for doing the PPM treatments and make recommendations for the time in the pavement life the treatments should be placed. Contact: Tim Stahl, 507-847-2525
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862
Development of A-Real-Time Arterial Performance Monitoring System Using Traffic Data Available from Existing Signal Systems

As mandated in the new transportation bill, SAFETEA-LU, a real-time system management information program will be established at USDOT to provide the capability for monitoring the traffic and travel conditions of the transportation network. Despite recent developments on the real-time measurement of freeway performance using routinely available loop detector data, no similar approaches exist for the performance monitoring of urban arterial street networks. This project aims to fill in this gap. The goal of this project is therefore to develop a real-time online performance monitoring system for the arterial streets. The arterial performance data will be also archived and made available to various stakeholders for operation, planning, research and traveler information systems, in a similar way as the freeway performance data. In this project, data availability and requirement from existing signal system will be analyzed, and algorithms for the estimation and prediction of real-time arterial travel time and speed will be developed depending upon the data resolution. These estimation algorithms will be first tested with microscopic simulation model. If successful, a prototype system with field demonstration will be expected. Contact: Eric M Drager, 612-596-0309
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863
Optimal Timing of Preventive Maintenance for Addressing Environmental Aging in HMA Pavements (Pooled Fund Project)

One of the major tasks in any transportation agency pavement management system is to select the appropriate alternative for rehabilitation and maintenance. There is a need to understand how preventive maintenance improves the performance of the existing pavements, to develop new techniques, and to determine the optimal timing for the application of these treatments. Perhaps the main reason to apply a preventive maintenance treatment to an HMA pavement is to reduce the aging of the asphalt binder and therefore maintain a higher level of pavement performance. Some research has documented the aging to asphalt through traffic loadings. However, the mechanisms that cause environmental aging are not well understood. This research aims to better understand the mechanisms behind aging and therefore apply the right surface treatment at the right time. The goal of this study is to determine the proper timing of preventive maintenance treatments in order to optimize life cycle costs and pavement performance. Environmental aging of the asphalt binder in the underlying pavement is not well understood, and this project will seek to better understand the aging mechanism and how it can be reduced through pavement preservation. Contact: Jim Klessig – Research Services, 651-282-2472
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864
Recycled Asphalt Pavements (Pooled Fund Project)

The use of reclaimed asphalt pavement (RAP) has become a part of the daily practice in the construction of hot mix asphalt pavements. Besides the cost savings on materials, the use of RAP represents an environmentally positive method of recycling. Significant experimental work has been performed in the lab to evaluate the asphalt mixtures modified with RAP materials. However, the performance of pavements built with RAP is very hard to come by. Many pavements have been built in Minnesota and around the United States using RAP, but very few have been monitored closely to provide useful performance data. Questions remain about the viability of using RAP in a wearing course. The main idea of the project is to monitor several sections built at the Minnesota Road Research Facility (MnROAD) specifically to study RAP under controlled testing conditions. The sections may contain identical structural designs and hot mix asphalt mix designs, with the only variable being the percentage of RAP in each of the mixes. The final scope and work plan for the study will be developed by the participating states. Contact: Jim Klessig – Research Services, 651-282-2472
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865
Low Temp Cracking in Asphalt Phase II (Pooled Fund Project)

Low temperature cracking is the most prevalent distress found in asphalt pavements built in cold weather climates. As the temperature drops the restrained pavement tries to shrink. The tensile stresses build up to a critical point at which a crack is formed. The current Superpave specification attempts to address this issue by specifying a limiting low temperature for the asphalt binder. The specification does a reasonable job predicting performance of conventional asphalt cements, but this does hold true to polymer-modified asphalt binders that are manufactured to reach very cold temperature grades needed in cold climates. Currently the low temperature specification considers only the asphalt binder. Specifications must be developed for the asphalt mixture as well. It is very important to understand the mechanism of crack initiation and propagation. Thermal cracks can be initiated by traffic loading or cycles of temperature changes and then propagated by a large drop in temperature. In addition, the significant effects of aging and moisture on crack formation and propagation are not fully understood and need investigation. The main objective of this study is to validate the laboratory test procedures, models, and pavement design procedures that come out of Phase I of this study. This will be accomplished by monitoring two new test sections at the Minnesota Road Research Facility (MnRoad). Phase I was aimed at developing a fracture mechanics-based specification for a better selection of asphalt binders and mixtures with respect to their resistance to crack formation and propagation. This fracture mechanics approach will also be used to investigate the detrimental effects of aging and moisture on the fracture resistance of asphalt materials. Contact: Jim Klessig – Research Services, 651-282-2472
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866
Recycled Unbound Pavement Materials (Pooled Fund Project)

In the current global economy, the United States is in competition for non-renewable resources. In this country and Minnesota in particular, aggregate materials are being depleted a rapid pace. It is becoming increasingly important to investigate the use of recycled materials in pavement construction. The use of crushed concrete in particular has raised some environmental concerns. These concerns have focused on the relatively high pH of the effluent produced by drainage systems that remove water from untreated recycled concrete aggregate foundation layers. Also of concern is the identification and of some constituents (arsenic, chromium, aluminum, and vanadium) that are considered hazardous in drinking water. The objective of this study is to monitor the performance of several test cells at the Minnesota Road Research Facility (MnROAD) constructed using recycled materials in the granular base layers, including blended with virgin materials and 100% recycled asphalt and concrete pavement materials. The materials properties will be monitored during construction and throughout the pavement life in order to determine their effects on pavement performance. The properties will be used to verify mechanistic-empirical design inputs, especially their variation with changing seasons and moisture regimes. Contact: Eddie Johnson, 651-779-5465
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