01336705

Component

Mechanical models such as Maxwell and Kelvin models have been extensively used in the literature to model asphalt concrete behavior. Several numerical techniques for approximate calculation of relaxation spectrum based on these models have been developed in the past which can be used in computer based routine analysis/modeling. However, they require extensive computing resources and often the solution obtained is not unique and errors in these solutions increase at non-collocating points. The continuous relaxation spectrum method offers efficient alternative where these issues can be dealt easily. This research presents a simple and practical approach to obtain the exact representation of the continuous relaxation spectrum from the observed dynamic modulus test data. The relaxation spectrum is obtained from the fitted sigmoid function through inverse Fourier-Laplace transform approach. Subsequently, the relaxation modulus master curve is obtained. Also the effect of asphalt content and asphalt grade on relaxation spectra is studied using NCHRP 9-38 mixture test database. The shape of relaxation spectrum is dependent on the asphalt content of the mix. The relaxation spectra obtained from proposed method matched with those obtained from existing approximate methods at specific frequency range. The continuous relaxation spectrum thus obtained can easily be implemented in mix design process.

01329018

11-3954

English

18p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (9) ; References (14)

Asphalt concrete; Asphalt content; Asphalt mixtures; Dynamic modulus of elasticity; Fourier transforms; Hot mix asphalt; Mechanical properties; Mechanical relaxation; Mechanics; Mix design

Kelvin and Maxwell models

Highways; Materials; I31: Bituminous Binders and Materials

Transportation Research Board Annual Meeting 2011 Paper #11-3954

TRIS, TRB

Feb 17 2011 6:42PM