Investigation of electromagnetic gauges for determining in-place HMA density.

779854435Final report.PDFTech ReportIHRB Project TR-547CTRE Project 05-233Electromagnetic devicesHot mix paving mixturesNondestructive testsQuality of workIowaIowa State University. Center for Transportation Research and EducationKvasnak, Andrea N.Williams, R. ChristopherCeylan, HalilGopalakrishnan, KasthuriranganIowa State University. Center for Transportation Research and EducationIowa. Highway Research BoardIowa. Dept. of TransportationNTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATIONNTL-HIGHWAY/ROAD TRANSPORTATION-MaterialsNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceUS Transportation CollectionDensity is an important component of hot-mix asphalt (HMA) pavement quality and long-term performance. Insufficient density of anin-place HMA pavement is the most frequently cited construction-related performance problem.This study evaluated the use of electromagnetic gauges to nondestructively determine densities. Field and laboratory measurementswere taken with two electromagnetic gauges\ue2\u20ac\u201da PaveTracker and a Pavement Quality Indicator (PQI). Test data were collected in thefield during and after paving operations and also in a laboratory on field mixes compacted in the lab.This study revealed that several mix- and project-specific factors affect electromagnetic gauge readings. Consequently, theimplementation of these gauges will likely need to be done utilizing a test strip on a project- and mix-specific basis to appropriatelyidentify an adjustment factor for the specific electromagnetic gauge being used for quality control and quality assurance (QC/QA)testing. The substantial reduction in testing time that results from employing electromagnetic gauges rather than coring makes itpossible for more readings to be used in the QC/QA process with real-time information without increasing the testing costs