Over the past decade, the Rolling Dynamic Deflectometer (RDD), a continuous deflectionmeasurement device, has been used as a powerful screening tool in identifying problematicairport pavements to be repaired. However, the RDD has not seen much use as anevaluation tool to measure characteristics such as moduli of pavement layers and loadtransferefficiency (LTE). The primary goal of this research is to take the RDD from ascreening tool to an evaluation tool for airport pavement projects by developing the hardwareand software. In this study, the RDD as an evaluation tool could obtain: (1) continuousmeasurement of rolling deflection basins (for the backcalculation of layer moduli to bestudied) and (2) continuous evaluation of joint LTEs. Four subtasks have been conducted:(a) investigation of parameters affecting the RDD measurements, (b) increase the number ofrolling sensors, (c) improvement of RDD data processing (distance-based deflection profilewith increased spatial resolution), and (d) a series of field tests with the RDD on a rigidairfield pavement. With all five sensors continuously being monitored during rolling,software developed was capable of selecting a zone of lateral uniformity over which it isappropriate to construct deflection basins. The improved data processing identified accuratelocations of joints, and properly positioned two rolling sensors on opposite sides of theadjacent slabs in the continuous deflection profile, resulting in continuous LTE evaluationalong the pavement. The RDD measurements (continuous deflection basins and LTEs) werecompared with Falling Weight Deflectometer (FWD) measurements, and their comparisonprovided promising results.
展开▼
