Vittorio Nicolosi

A New Methodology for Stochastic Modelling of Pay Factors in Hot-Mix Asphalt Pavements

ABSTRACT Since 1990 several research projects developing any Pay-Adjustment (PA) procedure for implementing Performance Related Specification (PRS) in Hot-Mix Asphalt (HMA) pavement construction have been issued. Previous studies proved that an approach based on life-cycle cost analysis and Monte Carlo simulation was an effective way to develop rational pay-adjustment procedures. However, the PRS systems developed so far had some significant weaknesses in the modelling of the variability of Materials and Construction (M&C) characteristics with corresponding PA. Furthermore they are mainly based on an empirical approach rather than on a mechanistic one. A new approach to model M&C variability in PRS systems, based on beta distribution, is introduced and a new stochastic method for pay-adjustment evaluation is developed. These criteria were embedded in a mechanistic system framework based on life-cycle cost analysis and Monte Carlo simulation. The model has been recently applied to a real case study and results are reported and analysed in this paperwork.

Preliminary Investigation on a Numerical Approach for the Evaluation of Road Macrotexture

Safety aspects, as dry and wet friction and splash and spray phenomena, and environmental aspects, as rolling noise, in-vehicle noise and rolling resistance are highly affected by the pavement surface macrotexture. For these reasons, predicting macrotexture, is a crucial aspect for pavement engineers. In this connection, several statistical empirical models have been proposed in the scientific literature. However, none of them seems to be effective in predicting macrotexture. For these reason, in order to better understand relationship between grading and volumetric properties of bituminous mixes and the corresponding macrotexture level a more theoretical approach has to be pursued.