Output from the Greenwood Traffic Speed Deflectometer

Abstract

The purpose of this paper is to describe the Greenwood Traffic Speed Deflectometer (TSD) concept which uses Laser Doppler technique which applies the load of a real truck in traffic. Therefore, the pavement response under the TSD authentic is more accurate compared to the response from the falling weight. The paper gives concrete examples of interpretation of data measured with TSD. As the TSD provides continuous measurements at traffic speed, then strategy for collecting pavement bearing capacity information can be developed and it becomes possible to identify local in homogeneities due to the fact that traditional stationary deflectometers use a falling weight as opposed to the new TSD. The TSD system has been developed to production level for network survey. The system operates successfully with non-contact deflection measurements. The high data resolution gives opportunity to obtain detailed output that can be regarded as continuous. The TSD output is reliable and has reproduced output variations that compares with FWD and has reproduced output patterns on a test section when measured at different driving speed levels.