Predicting tire/pavement noise impact reduction using numerical simulation and experimental data for open graded asphalt mixture

The environmental impact of noise from roads and highways traffic is relevant in urban and rural areas. The use of open-graded asphalt pavements reduces significantly the noise, entrapping the acoustic waves inside the porous structure of the material. In this paper we propose a simulation approach in order to predict the acoustic properties of the asphalt mixture from geometrical and topological indicators. In detail we have generated, using a Random Sequential Adsorption model, synthetic samples starting from the same grading and bitumen contents of real samples manufactured in laboratory. We have measured the acoustic adsorption coefficient of the real samples and we have investigated the correlation between this coefficient and some numerical indicators extracted from the simulated samples. Dimension and content of voids seem to be the most significant indicators for predicting acoustic properties of HMA. These correlations, that seem to be very promising, are useful in order to optimize the design of HMA in the perspective of minimizing noise impact