USING SCANNING LASERS FOR REAL-TIMEPAVEMENT THICKNESS MEASUREMENT

摘要

This paper examines a system that could determine the thickness of the pavement in real timernby laser scanning the surface of the subgrade prior to paving, and then scanning the surfacernafter paving. By having this data, the pavement can be evaluated for conformance to projectrnrequirements for thickness. This paper also examines existing nondestructive methods ofrnmeasuring pavement thickness including impact echo and high frequency ultrasound, andrnpresents the advantages of each in relation to a scanning laser based system. Existing 3Drnimaging techniques are discussed such as shadow moiré, ground penetrating radar, stereornvision, and airborne radar. Laser scanning provides a thorough coverage of the pavement thatrnwill assure transportation authorities that the entire pavement surface meets thicknessrnrequirements. Other benefits from this technique involve being able to determine concreternyield quantities and possibly smoothness. This sensor will be able to provide real time depthrnmeasurements as a profile of the concrete will be generated. Volume of concrete in place willrnbe easily determined using this approach. The system would fit on any paver that can providernposition coordinates and may be retrofitted onto a paver by using relative position control.