ABSTRACT
In France, the curviameter and the deflectograph are widely used for pavement deflection measurements. However, some comparisons made with reference devices such as anchored displacement sensors have shown that the rolling devices often measure different deflection bowls. The working principle of these rolling vehicles and some simplifying assumptions explain the differences and lead to measurement biases. Thus, the maximum deflection is often underestimated and moduli determined by back-calculation are not very realistic. For this reason, measurements are mainly used to identify homogeneous zones.
An approach, based on a three parameter model of the deflection bowl under a single wheel (Jouve and Martinez, 1990), has been developed to correct curviameter and deflectograph measurements. By using this model and superimposing the loads, the pavement deflection under the complete vehicle can be simulated. Then, the model parameters are optimized. Thanks to this model, a corrected deflection bowl, under a single-wheel, can be deduced and used for back-calculation, or to calculate different indicators similar to those used for the FWD.
