01658412

Component

Presented within the immediate context of the estimation of ‘bottom-up’ fatigue cracking in the Mechanistic-Empirical Pavement Design Guide (MEPDG), three fundamental questions are posed, regarding the future development of pavement design, asphalt mixture design, and the possible integration of both: (1) is it desirable to continue to predict pavement distress – or – attempt to prevent structural pavement failure? (2) is it desirable to model all forms of load-related cracking using the same general approach and/or mechanistic basis? (3) is it desirable to more fully integrate asphalt mixture characterization/design and flexible pavement design – such that, e.g., the material properties obtained during mixture design serve as direct inputs into pavement design? In exploration of these questions, short-term, long-term, and ‘aspirational’ recommendations are developed regarding future development of fatigue cracking models in the MEPDG. Short-term recommendations focus on the perpetual pavement concept. Long-term recommendations focus on developing a fracture-based fatigue model compatible with the current reflection cracking model (and anticipated for the future top-down cracking model) – but which is informed by advances in cracking tests currently being considered in mixture design. Aspirational recommendations focus on developments in visco-elastic continuum damage based procedures, which purport to integrate materials characterization (for mixture design) and structural pavement design. In a larger context, these questions are both applicable and vital to continued progress towards true performance-related specifications for pavement systems and associated decisions regarding future research investment and topical areas.

This paper was sponsored by TRB committee AFD60 Standing Committee on Design and Rehabilitation of Asphalt Pavements.

18-01094

English

19p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Asphalt mixtures; Fatigue cracking; Flexible pavements; Mathematical models; Mix design; Pavement design; Recommendations

Mechanistic-Empirical Pavement Design Guide

Design; Highways; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-01094

TRIS, TRB, ATRI

Jan 8 2018 10:16AM