The structural capacity of a flexible or concrete pavement should be evaluated when:
An increased number of vehicles, or a change in the vehicular traffic mix is envisaged.
The pavement is showing signs of distress, and the causes and extent of the distress need to be determined.
An overlay design is needed for the pavement.
The rate of deterioration of the pavement's structural capacity is being monitored over time.
The latest generation of deflection testing devices is impulse deflection equipment, more commonly known as the FALLING WEIGHT DEFLECTOMETER (FWD). A weight is lifted to a given height on a guide system and then dropped onto a load plate which is placed on the pavement surface. By varying the weight dropped and the height of drop, the impulse force can be varied. The impulse devices produce a pavement loading that is similar in magnitude, shape and duration to that produced by a moving wheel load. At PMS Pavement Management Services Ltd. we operate a Dynatest 8081 Heavyweight FWD with a range of 30 to 240 kN.
Structural Design for New and Existing Pavements
Falling Weight Deflectometer testing can be used directly for all your structural design requirements:
Using FWD and/or destructive testing, analytical pavement design and overlay design can be carried out using state-of-the-art software packages.
In-situ material properties for each pavement layer and subgrade can be determined.
Overlay thicknesses can be calculated based on present and future traffic volumes.
The FWD can be used in new pavement construction to test the quality and uniformity of sub-base and roadbase layers prior to the application of the basecourse and wearing course layers