| IT WORKS!! It is possible to accurately estimate the density of an asphalt mat based upon the vibratory signature of the compactor and other physical parameters. The benefit of this research to society is substantial, and the Penn State Model, or some system based upon it, will be the new best practice for asphalt compaction quality control in the near future. In Florida the Penn State Model performed as well as the nuclear density gauge and in New York it outperformed two nuclear density gauges. The Penn State Model can be calibrated to nuclear density gauge readings, core results, or, preferably, both. Changes to the underlying pavement structure can be detected immediately by the system, and the value of automated data in real time is immeasurable.;The current state-of-the-art and defacto standard for determining asphalt density for quality control purposes utilizes 1960's technology. The nuclear density gauge has served the industry well for thirty-plus years. It was a huge improvement over the methods used prior to its development. However, recent changes and trends have caused a need for new methods of monitoring the quality of asphalt pavement.;The desirability of an on-board density meter has inspired many attempts at developing such a device over the last twenty-plus years. An on-board density meter equipped with a computer capable of data storage could not only render continuous real-time density measurements, but also present the contractor and owner with a record of the density reading for every foot of the project length. This continuous stream of information allows the contractor to immediately cease operations whenever there is a density problem, thus avoiding the scenario of being ordered by the owner to rip out the pavement or accept a penalty for the substandard pavement. The Penn State Model offers all of these features. |
