FHWA High Density Demonstration Project

During the week of September 12th, S.L. Williamson Company of Charlottesville completed the FHWA High-Density Demonstration Project. VDOT was one of ten state transportation agencies to be awarded a FHWA grant to perform the project. The focus of the project was to achieve higher in-place density or lower in-place air voids. Through better and more uniform density, pavement life should be extended by reducing the intrusion of water and air into the pavement layers.

The project was performed in multiple stages. The first stage consisted of a pre-construction conference to ensure all parties were aware of the different compaction techniques that would be employed. The second stage included equipping the paver with an infrared camera to measure asphalt mat temperatures behind the screed. Additionally, an Intelligent Compaction Roller was provided by Carter Machinery to be used in one of the compaction approaches. The third stage was paving and compacting the asphalt on USS 522 in Louisa County. The asphalt mix was produced at the S.L. Williamson plant in Ruckersville and trucked to the site. The mix was run through a material transfer device and paved with a CAT paver. Day 1 was the VDOT standard paving and compaction procedures. Days 2, 3 & 4 were varied approaches on compaction techniques. Cores, nuclear and non-nuclear gauges were used to monitor density during production.

All results are being analyzed and some will be presented at the Fall Conference. More results will be shared at the Regional Asphalt Seminars in February/March 2017. Contact Sungho Kim at VDOT Central Office Materials if you have questions.