NPC owns and operates a state of the art Falling Weight Deflectometer. This device is a precision instrument that has many features which makes it universally accepted as the best non destructive testing device for the structural assessment of pavements. The FWD is used to measure the surface deflection of a pavement under the dynamic impulse load of a falling weight. Features of the service include spray paint marking and GPS measurement of test sites. This allows later visual verification and follow up investigation. To view a schematic diagram of the FWD, click on the link below. 

 

The deflection data can be used as input to a back calculation program to calculate pavement and subgrade E modulus. The E modulus is in turn used in pavement and rehabilitation design models. 

 

Click here for FWD diagram download