Influence of Laboratory Long-Term Aging on Selected Fracture Parameters of Asphalt Mixtures

Abstract

The paper presents the influence of laboratory aging simulation on fracture properties determined on 150 variants of asphalt mixtures. The fracture properties were determined by two different test approaches—semi-circular bending test (SCB test) and three-point bending test on beam specimens (3-PB test). The aging was simulated according to one of the methods defined in EN 12697-52 (storage of test specimens in chamber at temperature of 85 °C for 5 days). The evaluated group of variants covered asphalt mixtures for all road layers. The group was further divided according to used bituminous binder (unmodified vs. modified) and reclaimed asphalt content. The results showed that strength parameters (flexural strength and fracture toughness) increase with aging. It further shows that fracture work provides more complex information about the cracking behavior. For the aging indexes, it was found that for mixtures with modified binders and mixtures which did not contain reclaimed asphalt (RA), the values were higher. The aging indexes for fracture work showed different results for both performed tests.

Mini-Review on the Application of Nanomaterials in Improving Anti-Aging Properties of Asphalt

“…As an important component of asphalt pavement, asphalt material bonds loose aggregate into a whole after compaction . However, after aging, the brittleness of asphalt material increases, and the adhesive strength between asphalt and aggregates decreases. , It makes asphalt easy to peel from the surface of aggregates, causing pavement distress such as looseness and peeling. − Furthermore, the increasing brittleness of asphalt could reduce the tensile strength and fatigue resistance of asphalt concrete. , Consequently, asphalt pavement is prone to cracking in low-temperature environments or under repeated loading.…”

“…As mentioned above, heat, ultraviolet radiation, and oxygen make great contributions to asphalt aging. On the basis of their characteristics, the causes of asphalt aging can be divided into thermo-oxidative and ultraviolet aging. ,, The former covers short-term and long-term thermo-oxidative aging. Short-term aging is pointed to the aging reaction of asphalt that happens in the processes of production and compaction of mixtures.…”

“…10−12 As an important component of asphalt pavement, asphalt material bonds loose aggregate into a whole after compac-tion. 13 However, after aging, the brittleness of asphalt material increases, and the adhesive strength between asphalt and aggregates decreases. 1,14 It makes asphalt easy to peel from the surface of aggregates, causing pavement distress such as looseness and peeling.…”