Use of ground-penetrating radar for construction monitoring and evaluation of perpetual pavements

The inherent quality of perpetual pavement (PP) governs its performance, which consequently influences the frequency and level of the potential accidents during the whole service life. This paper presents the ground-penetrating radar (GPR) as a nondestructive testing (NDT) tool that was utilized for construction monitoring and evaluation of Texas (USA) perpetual pavements. The currently existing Texas PP sections typically consist of hot-mix asphalt layers of over 350-mm total thickness supported on a 200-mm-thick treated (6 % lime or 2 % cement) base, which is resting on a well-compacted in situ subgrade soil. Overall, the results indicate that the GPR has great potential as an effective NDT tool for aiding with the construction quality monitoring, forensic investigations, and structural/performance evaluation of PP structures. In particular, the GPR is useful in determining pavement layer thicknesses, assessing compaction uniformity, locating areas of moisture retention, identifying low-density spots and localized high voided areas, indicative assessment of vertical segregation and debonding, and quality assessment of construction joints. Additionally, the current GPR system has the advantage of rapidly and continuously collecting pavement data up to a depth of 610 mm, together with integrated video images and a GPS system, over any desired highway length while traveling at a nominal speed of about 113 km/h without disturbing conventional traffic.