Is Seal Coating Counterproductive or Not?

SPONSOR:  MINNESOTA DEPARTMENT OF TRANSPORTATION

PI:  Zhanping You

While seal coating has been widely used as a cost effective strategy in asphalt pavement preservation, many cities in Minnesota have reported their concerns of the premature stripping of street pavements under seal coating. As a result, there is a growing number of local agencies that are choosing not to use seal coating. The Minnesota Department of Transportation (MnDOT) wants to know if this premature stripping is caused by seal coating. If yes, then what is the mechanism for this? Is seal coating counterproductive in cities in Minnesota? A hypothesis proposed that premature stripping is caused by the high air void pavement, which allows water to intrude and spread, and the low surface breathability, which traps water in the asphalt pavement.

This research will investigate this problem through literature review, field data collection and lab testing. The lab tests include permeability and surface breathability tests, effect of air voids on moisture susceptibility, and effect of seal coating on moisture susceptibility.

The objectives of this research are to: 1) find out the causes of premature stripping of street asphalt pavement under seal coats; 2) investigate possible solutions to address pavement stripping under seal coats; 3) provide recommendations for the preservative strategies of street pavements in Minnesota.

Zhanping You
Zhanping You

Tire Rubber Modified Asphalt Emulsion for Effective Pavement Preservation

SPONSOR: MICHIGAN DEPARTMENT OF ENVIRONMENTAL QUALITY

PI:  Zhanping You

This project will evaluate the feasibility of GTR-emulsion and activated rubber for pavement chip seal. The feasibility study includes the emulsification and performance evaluation of GTR-emulsions, and trial field sections of chip seals for GTR-emulsions and/or activated rubber. The project will be considered successful if the following results are obtained:

(1) GTR-emulsion and ARMA is successfully prepared and its performance is evaluated in laboratory. Its properties meet the requirements of each standard. The comparison between regular-emulsion and modified emulsions is made for performance evaluation.
(2) GTR-emulsion and activated rubber chip seals are successfully prepared and the performance is evaluated through the laboratory paving of chip seals. The life cycle cost analysis of chip seals is used to evaluate the ROI and the comparison between GTR-emulsion chip seal and others will be made.
(3) The road trial sections of GTR-emulsion and activated rubber chip seals are successfully implemented.

Zhanping You
Zhanping You
Qingli Dai
Qingli Dai

Identify Best Practices in Pavement Design, Materials, Construction and Maintenance in Wet Freeze Climates Similar to Michigan

SPONSOR:  MICHIGAN DEPARTMENT OF TRANSPORTATION

PI:  Zhanping You

The success of this research project can enable MDOT to understand which best practices in other states or countries can be potentially implemented in Michigan. This would help Michigan to improve their pavement system by lowering construction and maintenance cost and extending pavement durability. It is also beneficial for MDOT to update their specifications, manuals and guidelines to be consistent with the development of those innovations in pavement design, pavement materials, construction and maintenance.

The objectives of this research are the following:

• Document best practices nationally and internationally for pavement design,   pavement materials selection, construction (workmanship), and maintenance of roadway pavements in wet freeze climates that are similar to Michigan.
• Identify barriers to implementing the best practices presently not used in Michigan.
• Recommend the best practices that could be implemented in Michigan.

Zhanping You
Zhanping You
Chris Gilbertson
Chris Gilbertson

Low Emission Asphalt Pavements with Crumb Rubber

SPONSOR:  MICHIGAN DEPARTMENT OF ENVIRONMENTAL QUALITY

PI:  Zhanping You

This project will conduct comprehensive evaluations on the CRM WMA for pavements in the State of Michigan.  The main objective of this project is to develop and apply low emission asphalt pavement technology through the combination of crumb rubber and warm mix asphalt and to evaluate the feasibility of CRM WMA with respect to performance improvement, emission reduction, and cost effectiveness. The performance of CRM WMA will be evaluated through laboratory and field testing. The emission reduction will be assessed through laboratory and plant emission measurements. The environmental impact of the CRM asphalt mixtures will be evaluated through LCA, while the cost effectiveness will be evaluated through LCCA.

The evaluation includes performance improvements, emission reduction, life cycle environmental impact assessment, and life cycle cost analysis. If it shows that the CRM WMA is a feasible option after the evaluation, it is anticipated the CRM WMA can have more applications in the future. And therefore a sustainable market for scrap tires can be developed in Michigan. In this project, we anticipate the CO2 output for the designed materials will be reduced by up to 30% and other volatiles will be reduced by up to 30% as well, while the engineering parameters of the pavement meet or exceed the pavement agency’s goal.

Zhanping You
Zhanping You

A Microstructure-Based Modeling Approach to Characterize Asphalt Materials

SPONSOR:  NATIONAL SCIENCE FOUNDATION

PI: Zhanping You

The short-term goals of this integrated research and education activities within the project period include: 1) development of a microstructure-based discrete element modeling approach to characterize asphalt materials; 2) implementation of the model to evaluate asphalt material response and performance to improve pavement structural design; 3) integration of the proposed research activities into the educational programs for high school students, K-12 educators, and undergraduate and graduate students, and; 4) dissemination of the research results through publications, conferences, and professional development for practicing professionals. The long-term goals are to: 1) establish a multi-user research and education center for asphalt material and virtual testing by integrating the proposed advanced modeling approach, and; 2) implement advanced technologies into pavement materials, locally through the Michigan Department of Transportation, and broadly through research collaborators and industry partners. This project will: 1) advance the understanding of asphalt pavement materials and pavement structures; 2) increase collaboration among researchers at many leading institutions and industries; 3) enhance scientific and technological understanding of micromechanical aspects of pavement infrastructure, and; 4) significantly reduce the cost of pavement infrastructure construction and maintenance. The development and application of the microstructure-based discrete element model in asphalt materials will enhance understanding by correlating material behavior to pavement performance.

The research will translate directly into improved asphalt mixture design and pavement thickness design. This in turn should create substantial cost savings. A one-percent decrease in asphalt concrete life-cycle cost would amount to approximately $500 million in U.S. Federal government savings alone. Activities are planned to advance discovery and understanding of asphalt pavement infrastructure materials while promoting teaching, training, and learning through specific activities for K-12 students and teachers, undergraduate and graduate engineering and science majors, and practicing engineers.

Zhanping You
Zhanping You

US-Malaysia Planning Visit: Collaborative Research on the Micromechanics of Cubic Stone Materials for Pavements

Sponsor: National Science Foundation

PI: Zhanping You

This award supports the participation of an American researcher, graduate student and undergraduate students in the planning visit which will take place in Malaysia. The visit will enable Professor Zhanping You in the Civil Engineering Department at Michigan Technology University to meet with Professor Meor Othman Hamzah in the School of Civil Engineering at the University Sains Malaysia (USM) in Penang. Their proposed project will involve: 1) increasing multidisciplinary collaboration among researchers in Michigan and Malaysia at their leading institutions; and 2) discovering the mechanism of rutting and fatigue distresses by using advanced micromechanics based discrete element models through the collaborative effort. The team will visit USM?s Asphalt Laboratory to work with the Malaysian professors and students to study and evaluate the feasibility of using cubical aggregated in pavement to reduce rutting potential. The students will also have an opportunity to participate in the testing of samples with/without cubic-stone materials on dynamic modulus and resilient modulus testing. The U.S. students will receive the testing results in order to use the data for discrete element modeling. The discrete element model will be further refined to study the various material phases (aggregates and mastic/asphalt) of pavement materials in order to determine the rutting and fatigue performance of asphalt pavements.

There is sufficient overlap of interests between researchers at the two universities to indicate that the researchers can successfully pursue the activities proposed, and the interaction will benefit both sides. This collaboration will advance discovery and understanding of cubic-stone materials micromechanics, while promoting teaching, training, and learning through the specific activities planned for the students. It is anticipated that the inclusion of the students in this visit will provide them unique training and educational opportunities by providing them a global research experience. These early collaborations between the scientists and students from each country will likely lead to long-term collaborations that will benefit both institutions.

Zhanping You
Zhanping You

EAGER: Using Nonmetals Separated from E-Waste and Waste Plastic Bags in Improving the Mechanical Properties of Asphalt Materials

Sponsor: National Science Foundation

PI: Zhanping You

The objective of this EAGER project is to investigate the possibility of improving the mechanical properties of asphalt materials with the use of nonmetals separated from E-waste (e.g., computers, monitors, keyboard, cameras, TVs, etc.) and waste plastic bags (e.g., grocery bags). E-waste and waste plastic bags are recycled materials that have potential to be used in asphalt materials. The research work will include shredding of the non-metallic separations and waste plastic bags into powders and particles, mixing the powder-like polymers and particles to modify selected asphalt materials in the laboratory, and evaluation of the mechanical properties of the modified asphalt.

Through its integrated research and educational plan, this project will advance discovery and understanding of infrastructural materials, while promoting teaching, training, and learning – impacting underrepresented high school students and teachers, undergraduate and graduate students, and professionals from industry and the government. This project will directly benefit society through improved transportation systems and lower infrastructure costs. The project also leads to collaborative efforts with a historically black Carnegie doctoral/research intensive public institution, Jackson State University.

Zhanping You
Zhanping You

Laboratory Evaluation of Warm Mix Asphalt

Sponsor: Michigan Department of Transportation

Photo courtesy of FHWA (fhwa.dot.gov)

PI: Zhanping You

Hot Mix Asphalt (HMA) has been traditionally produced at a discharge temperature of between 280°F (138°C) and 320° F (160°C), resulting in high energy (fuel) costs and generation of greenhouse gases. The goal for Warm Mix Asphalt (WMA) is to use existing HMA plants and specifications to produce quality dense graded mixtures at significantly lower temperatures. Europeans are using WMA technologies that allow the mixture to be placed at temperatures as low as 250°F (121°C). It is reported that energy savings on the order of 30%, with a corresponding reduction in CO2 emissions of 30%, are realized when WMA is used compared to conventional HMA. Although numerous studies have been conducted on WMA, only limited laboratory experiments are available and most of the current WMA laboratory test results are inconsistent and not compatible with field performance.

The main objectives of this study are: 1) review and synthesize information on the available WMA technologies; 2) measure the complex/dynamic modulus of WMA and the control mixtures (HMA) for comparison purpose and for use in mechanistic-empirical (ME) design comparison; 3) assess the rutting and fatigue potential of WMA mixtures; and 4) provide recommendation for the proper WMA for use in Michigan considering the aggregate, binder, and climatic factors.

The testing results indicated that most of the WMA has higher fatigue life and TSR which indicated WMA has better fatigue cracking and moisture damage resistant; however, the rutting potential of most of the WMA tested were higher than the control HMA. In addition, the WMA design framework was developed based on the testing results, and presented in this study to allow contractors and state agencies to successfully design WMA around the state of Michigan.

Zhanping You
Zhanping You

 

Development of Specifications for the Superpave Simple Performance Tests

Sponsor: Michigan Department of Transportation

PI: Zhanping You

This report describes the development and establishment of a proposed Simple Performance Test (SPT) specification in order to contribute to the asphalt materials technology in the state of Michigan. The properties and characteristic of materials, performance testing of specimens, and field analyses are used in developing draft SPT specifications. These advanced and more effective specifications should significantly improve the qualities of designed and constructed hot mix asphalt (HMA) leading to improvement in pavement life in Michigan. The objectives of this study include the following: 1) using the SPT, conduct a laboratory study to measure the parameters including the dynamic modulus terms (E*/sinϕ and E*) and the flow number (Fn) for typical Michigan HMA mixtures, 2) correlate the results of the laboratory study to field performance as they relate to flexible pavement performance (rutting, fatigue, and low temperature cracking), and 3) make recommendations for the SPT criteria at specific traffic levels (e.g. E3, E10, E30), including recommendations for a draft test specification for use in Michigan. The specification criteria of dynamic modulus were developed based upon field rutting performance and contractor warranty criteria.

Read the full report:
Development of Specifications for the Superpave Simple Performance Tests

Zhanping You
Zhanping You

Identify Best Practices in Pavement Design, Materials, Construction, and Maintenance in Wet Freeze Climates Similar to Michigan

SPONSOR:  MICHIGAN DEPARTMENT OF TRANSPORTATION (MDOT)

PI:  Zhanping You

Michigan is a state with high precipitation and cold winter temperatures (wet-freeze climate).  This wet-freeze climate makes the pavement system in Michigan different from many other regions.  Compared to other regions with different climates, the most noticeable pavement distress in Michigan is freeze-thaw induced damage.  Thermal cracking and fatigue cracking in asphalt pavements and transverse cracking and joint faulting in concrete pavement are also major forms of pavement distress.  In addition, potential damage from de-icing materials and snow removal vehicles are concerns.  These concerns have limited the usage of some pavement types that are widely used in other states or countries.

The success of this research project can enable MDOT to understand which best practices in other states or countries can be potentially implemented in Michigan.

The objectives of this research include:

  • Document best practices nationally and internationally for pavement design, pavement materials selection, construction (workmanship), and maintenance of roadway pavements in wet freeze climates that are similar to MI,
  • Identify barriers to implementing the best practices presently not used in MI,
  • Recommend the best practices that could be implemented in MI
Zhanping You
Zhanping You
Chris Gilbertson
Chris Gilbertson