Determination of Asphalt Concrete Viscosity by the Four-Point Bending Test

Abstract

In this work, a model for the dynamical four-point bending test is present, with particular emphasis on application to an asphalt concrete (AC) composite, a viscoelastic material, based on the Euler-Bernoulli theory, which approaches an equation where the Young modulus E can be substituted by the operator (E + γ∂/∂t), where γ is an internal damping parameter associated to the binder viscoelasticity and t is the time. As course aggregate in the composition of the AC mixture, the sintered aggregate of calcined clay was used, interesting to be employed as an alternative to the lack of natural course aggregate in some regions of the planet, where the presence of sedimentary rocks prevails. The results indicated that γ decreases with the temperature and loading frequency and the apparent noise in the stiffness versus strain curve is resulted from the natural vibration mode of the beam.

Interference of natural vibrations in four-point bending test on beams with asphalt composite made with calcined clay aggregate

“…However, in conditions where there is an insufficiency of superficial stone, these pavements can be composed of a rolled pebble from riverbeds, a solution that results in a lower technical quality of this upper layer and causes serious environmental impacts, stimulating the study of new materials. An alternative for this situation is to use sintered calcined clay aggregate (SCCA) as a coarse aggregate [2][3][4][5][6][7][8][9][10][11][12]. Specifically, regarding asphalt binder, its viscoelastic characteristics must also be taken into consideration in this composition, as its consistency and strains are a function of the variation in temperature and time of load application.…”