Ohio Asphalt Paving Conference features major lecture by professor Shad Sargand

Russ Professor of Civil Engineering Shad Sargand delivered a major lecture on “Best Practices for Controlling Segregation” in asphalt concrete (AC) pavement to an audience of over 350 professionals at the Ohio Asphalt Paving Conference on Feb. 1, 2023.  

Segregation of crushed stone aggregate in AC leads to premature cracking and failure in asphalt pavements, which is costly to repair. The Ohio Department of Transportation (ODOT) employs trained inspectors to monitor AC pavement construction, and when they see segregation, they can order the contractor to stop paving, find the cause of the segregation, fix the problem and repave the affected areas. The inspector’s engineering judgement may be disputed by the contractor, and in the worst case, the disagreement can result in a court case.  A more objective measurement or test which can be quickly employed on site — as opposed to analyzing specimens in a lab — would reduce disputes, delays and costs associated with repaving problem areas.   

The lecture recapped what the Ohio Research Institute for Transportation and the Environment (ORITE) learned in the course of a research project which included a survey of pavement engineers from departments of transportation (DOTs) across the United States and Canada, a literature search and an examination of state DOT documents including construction and materials specifications, test methods and published guidelines. While the research did not identify a major breakthrough that has been widely adopted, a number of useful techniques and technologies were identified for further consideration.   

The report documented a research project Sargand led, which was the latest of nearly 100 projects he has successfully completed for ODOT, most of them on flexible and rigid pavements and on highway drainage conduits, particularly thermoplastic pipes. Many of the findings and recommendations in these reports have been successfully implemented by ODOT to improve Ohio’s transportation network and save tangible amounts of public funding.

Sargand was also awarded the William W. “Bill” Baker Award in 2011 for his career contributions to the asphalt community. He has also organized three International Conferences on Perpetual Pavement.  

The Ohio Asphalt Paving Conference is an annual event hosted by Flexible Pavements of Ohio, an asphalt industry trade organization. The conference represents the participation of people from all sectors of the industry, including state and local government, contractors, consultants and academic researchers. Attendees learn up to date information concerning new developments and techniques and are provided practical, usable solutions to problems encountered in the design and construction of asphalt pavements. This year’s conference was held at the Fawcett Center at the Ohio State University in Columbus. It was a hybrid event, and Sargand’s lecture was delivered to over 200 people in the room and another 150-200 participating online.  

More information on the conference can be found at at this website. The entire ODOT project report, entitled Detection of Segregation in Asphalt Concrete Pavement, can be found online and downloaded at this website.