Fatigue Resistance of Asphalt Concrete Pavements. Peculiarity and Assessments of Potentials

Abstract

This article presents the results of research of processes of deformation and destruction of asphalt concrete pavements under cyclic loads. As the ground for such approach to estimation of the asphalt concrete properties served the proof that regardless of the composition and structure of asphalt concrete with an equal amount of elastic (viscoplastic) bonds possess the same relaxation ability. This situation is a significant feature of the behaviour of asphalt concrete, which opens the way for the development of certain approaches to the analysis of their properties, evaluation of reliability and durability. The promising methodology for the comparative assessment of fatigue and cyclic durability of asphalt concrete by exploring the complex set of elastic and viscoplastic bonds in their structure depending on the temperature, magnitude, and modes of action of the loads is proposed in the presented work. In the future, the establishment of patterns of behaviour of asphalt concretes with the same set of elastic bonds is allows to optimize compositions based on the principles of temperature-structural analogythat is relevant in studying fatigue and cyclic durability as well as low-temperature crack resistance and shear stability.

Prospects for Evaluating the Damageability of Asphalt Concrete Pavements During Cold Recycling

“…It may be explained by the fact that at the same number of bonds, slowing down the relaxation rate implies a decrease in the relaxation rate constant by the same amount. This is the most important feature of the behavior of the studied materials, which allows us to develop new approaches to the analysis of their properties (Li, Liu, Shi, Veranko, & Zankavich, 2017).…”

“…In this case, the number of n r and n v depends primarily on the relaxation properties of asphalt concrete and the time of action of the load. The number of elastic bonds involved in the deformation process can be determined from the following dependency (Li et al, 2017;Verenko, 1993;Verenko & Makarevich, 2010):…”

“…Since the number of cycles before failure depends on the ratio of acting stresses to strength, the higher the R c , the greater is the cyclic stability of asphalt concrete in the elastic stage of work, and the higher is the level of damageability in the material that can be achieved at the time of failure. Consequently, the R c value can serve as a criterion for cyclic durability under constant stress in the elastic stage of work (Li et al, 2017). The maximum asphalt concrete strength over the entire temperature range (loading exposure time) can be calculated using the results of a split test, or indirect tensile test, of the standard cylindrical samples according to the following dependency (Verenko, 1993;Verenko & Makarevich, 2010):…”

“…Since an increase in R c increases the probability of an improvement in durability in the elastic stage of acting and an increase in ε m -in the viscous stage, in general (0 < n r < 1), the materials with the maximum value of the product of R c ε m will have the maximum cyclic durability (Li et al, 2017).…”

“…as a basic model, the value of the reduced amount of dissipated energy can be replaced with sufficient accuracy for practice by the ratio of the actual number of cycles of load application N f to the limit N m (Li et al, 2017). When processing experimental data, there were the limit values of cycles before the destruction of samples from repeated freezing-thawing, which are set graphically by extrapolation methods considering the type of the degradation curve (Figure 2a).…”