James Berry, P.E. Project Manager

G2 Consulting Group is expanding its Hot-Mix-Asphalt (HMA) testing capabilities at its Troy laboratory with the addition of a new Superpave Gyratory Compactor (SGC).  The new machine is a Model AFG2 manufactured by Pine Test Equipment, Inc. The SGC will allow G2 Consulting to test and determine the volumetric properties of the newer Superpave HMA mixtures (MDOT E series mixes) that are being used more and more by our local and regional agency clients.

What is Superpave?

Superpave stands for Superior Performing Asphalt Pavements. It is a mixed-design method that makes the best use of asphalt paving technology and enhances asphalt pavements’ ability to balance the high-temperature rutting and low-temperature cracking characteristics of asphalt concrete. Superpave replaces the Hveem and Marshall methods.

Why is it important?

Harvey Hurwitz, Senior Engineering Technician demonstrates compaction sampling.

Determining volumetric properties of compacted HMA samples is an important component of mix design development and project quality control and quality assurance testing. With the older Marshall designed mixes, this was relatively easy with simple mechanical compaction equipment. Superpave mixes require the much more sophisticated SGC to compact the laboratory samples for testing. The SGC allows us to produce samples in our laboratory representing a variety of different projected traffic loadings using compaction methods that more closely simulate mix compaction under repeated vehicle wheel passes rather than compaction with a smooth drum roller. Many regional agencies are requiring volumetric properties tests as part of standard QA/QC testing, and it is anticipated that MDOT Local Agency Projects will require QA volumetric testing for Marshall and Superpave HMA mixtures in the near future.

G2’s new Superpave Gyratory Compactor will be used to test newer Superpave Hot Mix Asphalt mixtures.