01373372

Component

In this paper, empirical acoustic models were developed for four asphalt surface mixes, including conventional dense-graded asphalt concrete (DGAC), open-graded asphalt concrete (OGAC), rubberized open-graded asphalt concrete (RAC-O), and rubberized gap-graded asphalt concrete (RAC-G). Tire/pavement noise data were collected from in-service flexible pavements at different frequency bands for four consecutive years. These data were panel structured, and with a portion of observations missed arbitrarily. Thus two major issues are associated with the data in the modeling: one is unobserved heterogeneity, which may lead to a biased and inconsistent estimation through ordinary least square (OLS) model due to potential violations of its basic assumptions; the other is the deficiency of missing observations, which suffers from mass loss of information using classical regression approach. In this paper, a Monte Carlo Markov Chain (MCMC) sampling and a multiple imputation (MI) algorithm were used to capture the unobserved heterogeneity and deal with missing observations by Bayesian simulations simultaneously. Individual models for each mix at different frequency bands were constructed. Major findings from predictions of these models include: first, tire/pavement noise increases with age at all frequency bands; second, tire/pavement noise level increases with air-void content of the surface mixes at medium and high frequencies but decreases at low frequencies; third, tire/pavement noise level increases with mean profile depth (MPD) at low and medium frequencies but decreases at high frequencies; forth; RAC-O alternative demonstrates superior acoustic performances at all frequency scenarios.

This paper was sponsored by TRB committee AFD90 Surface Properties - Vehicle Interaction

01362476

12-2544

English

2012

Transportation Research Board 91st Annual Meeting

Digital/other

Figures; References; Tables

Asphalt concrete; Asphalt mixtures; Dense graded aggregates; Flexible pavements; Monte Carlo method; Tire/pavement noise

Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways

Transportation Research Board Annual Meeting 2012 Paper #12-2544

TRIS, TRB

Feb 8 2012 5:10PM