Description
The Lacroix Deflectograph is a pavement testing vehicle that is used for the following applications. Measure the deflection basin of a pavement under the action of a heavy vehicle moving at constant speed.
It allows the application of the different operating modes of the IFSTTAR method n°39 for measuring surface deformability.
It is used for :
- Monitoring a road network.
- Detection of defective areas to be reinforced.
- Construction site control.
Winter monitoring (laying or lifting of thaw barriers).
The deflection is measured between each pair of rear axles of the vehicle of the vehicle’s rear axle by sensor arms fitted with sensors and articulated on a reference beam.
This reference beam, detached from the vehicle rests on the roadway at three points outside the load influence of the load. As the vehicle moves forward, the the deflection is recorded until the couplings. The reference beam is then brought back to its original position.
The reference beam is then brought back to the front of the vehicle and repositioned on the roadway for a new measurement, without interrupting the measurement, without interruption of the carrier vehicle. The measurement is thus continuous (measurement step <= 5m).
The correlation with static deflection measurements (by means of sensors anchored in the road) is very good, even for very small deformations of the road.
