The Curviameter is a very appropriate high precision equipment for the measurement of deflections in an extensive Roadway Network for a Pavement Management System (except in cases of rigid pavements and areas with extremely small radius curves). It may also be used for the calculation of pavement strengthening for rehabilitation and maintenance projects. Due to the measurement sequence it also allows areas with a homogeneous behaviour to be determined, calculate their representative deflections, as well as locate singular points of low bearing capacity. The use of the Curviameter allows the identification of homogeneous zones and provide data which can be statistically analysed for a later calculation of the costbenefit analysis of rehabilitation works.
How does it work?
Curviametro measured the deflection velocity in a large number of points and then could integrate this to a deflection. Three geophones are mounted on a fifteen meters long closed-loop chain that travels on the pavement surface between the dual rear wheel. The acceleration and velocity of the surface during a passage of the rear wheel is recorded, starting one metres before the wheel passes and stops three metres after. The Curviametro can assess both the deflection and the radius of curvature of the pavement deflection bowl at a speed of 18 km/h. This method is able to generating a result every five metres. A variable rear load made it possible to vary the rear axle load from 8 to 13 tonnes.
The advantages of the system
- Continuous determination of load bearing capacity
- Strong correlation between Falling Weight Deflectometer (FWD) and the Benkelman Beam.
- Calculation of values according to Jendia (every 5.00 m)
- Measurement of the deflection bowl every 5m (16,4 ft) with resolution of 100 points sampling.
- Creation of homogeneous sections for systematic taking of core samples
- High-resolution front camera images of the sections being surveyed.
- Overlap with road inventory and condition data / ground penetrating radar data for the drafting of construction programmes
- It enables a perfect connection to the pavement management systems, road inventory and service condition.
- Measurement of the deflection at 18 km/h (11mph) per hour
Examples of measured and calculated parameters:
- Deflection Max
- Deflection Bowl parameters
- Radius
- Tª air: Air Temperature (°C)
- Tª sup. Pav.:Temperature of the surface (°C)
- C temperature: Temperature Coefficient
- C season: Season Coefficient
- D temp. and season (mm): Corrected static deflection value (mm)
- Measured / calculated moduli (MPa)
- Pictures
- GPS coordinates
Data processing:
The data recorded by the unit are analysed with in-house programs that provide applications for managing deflection and associated images in computerised form. They can also be integrated into pavement management systems already in place. The experts of the T7 Mérnökiroda Kft. carry out the processing of data according to the demand of the costumer. Having the processing performed, the database of the results is transferred in a format requested by the customer.
The Curviametro meets the following standards:
Norme Francaise NF P 98-200-7. Decembere 1997 – Measure de la deflexion engendrée par une charge roulante
Arbeitspapiere Tragfahigkeit Teil B 4: Curviametro, Geratebeschreibung Messdurchführung Ausgabe, 2012
Normas NLT-336/06 II. Ensayos de firmes. Medida de las deflexiones en firmes con curviametro
Norma DNIT 170/2016 – PRO, Fevereiro/ 2016, Pavimentos – Determinacao de deflexoes utilizando o Curviametro – Procedimento
