The project will support the PI, Dr. Andrew Braham of the University of Arkansas, to visit Nanjing, China, to collaborate with Dr. Fujian Ni of Southeast University and Mr. Alex Tao of MeadWestVaco. Technical collaboration will center on the use of Digital Image Correlation to capture both bulk and separation properties of asphalt concrete during fracture testing. Fracture testing is becoming a popular technique for quantifying cracking characteristics of asphalt concrete in the laboratory. However, current data collection in the area of asphalt concrete often relies on stationary gauges to collect the data. While the data collected can be quite accurate, a large disadvantage is that data can only be collected at the point the gauge is attached to the sample. With Digital Image Correlation, pictures are taken of the sample during the whole test, so displacement and strains can be calculated across the entire specimen face, instead of just a single point on the sample. This will most likely be the future of materials testing, and this collaboration will provide the opportunity to establish the path forward in implementing the new data collection technique. In addition, the three groups will explore the research needs of a multinational company, MeadWestVaco, and how Southeast University and the University of Arkansas can address these needs. This initial collaboration between Dr. Ni of Southeast University, Mr. Tao of MeadWestVaco, and Dr. Braham of the University of Arkansas will set the stage for what we hope is years of future collaborations between the three entities.
Broader Impact: It is estimated that 94 percent of the pavement surfaces in the United States are asphalt concrete. The driving public is well aware of the construction and associated delays necessary in order to maintain the roadways we all enjoy. In order to reduce the amount of distresses in pavement surfaces, this international collaboration will study cracking characteristics of asphalt concrete. This group will use both traditional and more innovative equipment to capture cracking data in the laboratory, which will translate into longer lasting and less expensive roadways. Traditional measurements take readings at one time from specific points on the sample, much like measuring a distance with a ruler. More innovative equipment uses a camera that takes pictures, allowing for measurements to be taken across the entire sample face both during the testing and after the test has been completed. This project will strengthen international research collaboration network on this topic.
The Principle Investigator traveled to Nanjing, China and Shanghai, China to meet with university and industry representatives. The goals of the research were to: 1. Refine the use of Digital Image Correlation (taking pictures) in capturing displacement data from cracking tests of asphalt concrete. 2. Explore the needs of the pavement industry in the US and China and see how the University of Arkansas can help address those needs. 3. Construct a framework for future student exchanges and internships between the University of Arkansas and China. These three goals were met in the following ways. First, multiple variables were identified with using images to track displacement data from asphalt concrete tests. These variables must be either minimized or eliminated if the technology can be implemented on a regular basis. Techniques of analyzing images were also shared and discussed in order to obtain more accurate test results. Second, funding for one graduate student was obtained from industry for a two year period. This student will focus on researching advanced test methods in order to further understand the challenges facing pavement materials. In addition, the topic of a journal published was discussed and finalized for submission in August, 2012. Third, multiple routes of student exchange, from undergraduate to graduate, were discussed. There is interest in both China and the US for an exchange program, on the academic and the research side. Channels of communication will be kept open in order to create opportunities for students interested in studying or performing research abroad. In addition, industry representatives expressed interest in having University of Arkansas undergraduate students internship with their company over summer sessions. Overall, the Principle Investigator gained valuable knowledge, contacts, and information that will greatly aid in further the knowledge of pavement materials.