DEVELOPMENT OF A HIGH-SPEED ROLLING WHEEL DEFLECTOMETER

Abstract

Applied Research Associates, Inc. (ARA) is developing a high-speed Rolling Wheel Deflectometer (RWD) under SBIR/FHWA-sponsored research. The current RWD consists of a dual-wheel, single-axle semitrailer equipped with four spot laser mounted on an aluminum beam beneath the trailer. Three láser are used to measure the unloaded pavement surface, and the fourth laser, placed near the center of the dual tires, measures within the deflection basin under an 18-kip single axle load. The RWD has been assembled, and preliminary field runs have been made on thin and thick AC pavement sections. The RWD results have been compared to Falling Weight Deflectometer (FWD) and accelerometer-determined deflections on the same pavement sections and have produced encouraging results, although with some limitations. Several needed improvement were identified. Future plans for the RWD include system upgrade, further field testing over a wider variety of pavement types and conditions, demonstrations, including comparisons to instrumented test pavements, and eventually the manufacture of a production-level device.