Performance related characterisation of the mechanical behaviour of asphalt mixtures

Performance related characterisation of the mechanical behaviour of asphalt mixtures

Molenaar, J.M.M.

Molenaar, A.A.A. (promotor)

Civil Engineering and Geosciences

2004-01-20

The investigation was undertaken to support innovations in the field of asphalt pavement design and material selection, and to be able to evaluate or judge the risk of failure and cost-effectiveness of newly developed paving materials in order to justify their application. To be able to determine the risk of failure and cost-effectiveness, information is needed about the quality of the pavement. In order to define the quality of the pavement, it is necessary to know the behaviour of the applied materials. In order to know the behaviour of the materials it is necessary to know the properties that are relevant for the behaviour of the material in the pavement. The following aspects of the mechanical behaviour of asphalt mixture were investigated, because it is known based on experience that these are the important phenomena: the viscoelastic and viscoplastic stress strain behaviour, and the crack-growth behaviour. Both analytical and numerical approaches were followed. Test methods were developed that are suitable for use in a practical context for the determination of the stiffness modulus, the resistance to permanent deformation, and the resistance to fatigue and crack-growth. It is concluded that the following tests are suitable for the characterisation of the mechanical behaviour of asphalt mixtures in a practical context: a four point bending frequency sweep test, to characterise the linear dynamic viscoelastic stress strain behaviour, a dynamic triaxial creep test, to characterise the nonlinear dynamic elasto-viscoplastic stress strain behaviour, a tensile test, to characterise the resistance to crack-growth, and a fracture toughness test, to characterise the resistance to fracture. Those properties are important to the functionality of the pavement structure that is defined in terms of bearing capacity, surface characteristics, and long-term behaviour. It is concluded that it is possible, based on the tests mentioned, to develop a set of performance related specifications, which will allow newly developed asphalt mixtures to be tested for applicability relative to standardised asphalt mixtures for which the behaviour is known. Analytical methods will allow one to determine useful improvements to paving materials faster than empirical methods, and to obtain the information required to judge a newly developed and non-standardised paving material for its risk of failure and cost-effectiveness. Therefore, the use of analytical methods will facilitate the acceptation for application of innovative, non-standardised, paving materials.

Asphalt mixture
performance related characterisation
mechanical property
creep
permanent deformation
crack-growth
fracture
constitutive modelling

http://resolver.tudelft.nl/uuid:fb3a65fc-4c8e-491b-b444-dfabb96241eb

Delft, Road and Hydraulic Engineering Institute

90-369-5556-4

Institutional Repository

doctoral thesis

(c) 2003 J.M.M. Molenaar