Study on Method of Asphalt Density Measurement Using Low Level Radioactive Isotope

The fundamental cause of damage to road pavement is insufficient management of asphalt density during construction. Currently, asphalt density in Korea is measured in a laboratory by extracting a core sample after construction. This method delays the overall time of measurement and therefore it is difficult to achieve real-time density management. Using a radioactive isotope for measuring asphalt density during construction reduces measuring time thus enabling realtime measurement. Also, it is provided reliable density measurement to achieve effective density management at work sites. However, existing radiological equipment has not been widely used because of management restrictions and regulations due to the high radiation dose. In this study, we employed a non-destructive method for density measurement. Density is measured by using a portable gamma-ray backscatter device having a radioactivity emission of 100 μCi or less (notice No. 2002-23, Ministry of Science and Technology, standards on radiation protection, etc.), a sealed radioactive source subject to declaration