Recycling Aged Asphalt Using Hard Asphalt Binder for Hot-Mixing Recycled Asphalt Mixture

Abstract

Increasing the content of reclaimed asphalt pavement material (RAP) in hot-mix recycled asphalt mixture (RHMA) with a satisfactory performance has been a hot topic in recent years. In this study, the performances of Trinidad lake asphalt (TLA), virgin asphalt binder, and aged asphalt binder were first compared, and then the modification mechanism of TLA on virgin asphalt and aged asphalt was explored. Furthermore, the RHMA was designed in accordance with the French norm NF P 98-140 containing 50% and 100% RAP, and their high-temperature stability, low-temperature cracking resistance, and fatigue performances were tested to be compared with the conventional dense gradation AC-20 asphalt mixture. The results show that the addition of TLA changes the component proportion of virgin asphalt binder, but no new functional groups are produced. The hard asphalt binder modified by TLA has a better rutting resistance, while the fatigue and cracking resistance is lower, compared to both aged and virgin asphalt. The high-modulus design concept of RHMA is a promising way to increase the RAP content in RHMA with acceptable performance. Generally, the RHMA with 50% RAP has similar properties to AC-20. And, when the RAP content reaches 100%, the high- and low-temperature performance and anti-fatigue performance of RHMA are better than AC-20 mixture. Thus, recycling aged asphalt using hard asphalt binder for hot-mixing recycled asphalt mixture to increase the RAP content is feasible.

Gilsonita: Un mineral orgánico con propiedades físico- químicas especiales, usos actuales y perspectivas de futuras aplicaciones.

“…Ligantes bituminosos fueron mezclados con 18% de gilsonita (26) y un 5% de polímero estireno-butadieno-estireno (EBE), y el estudio mostró un aumento de la consistencia de los ligantes lo que afecta positivamente la susceptibilidad térmica del pavimento. (26) Zhou et al (27) realizaron pruebas utilizando la gilsonita ATT como ligante asfáltico, mezclándolo con material reciclado de una carretera (RAP) al 50% y al 100% con material asfáltico nuevo. En la mezcla al 50%, las características reológicas del material se mantenían iguales y sin cambios detectados comparados con el asfalto envejecido en carretera.…”

“…En la mezcla al 50%, las características reológicas del material se mantenían iguales y sin cambios detectados comparados con el asfalto envejecido en carretera. Se notó mejoría en el material en cuanto a la resistencia del proceso de envejecimiento y las propiedades reológicas, cuando la cantidad de aditivo fue al 100% para la mezcla asfáltica (27).…”

Microstructure in Adhesion Development Process and Strength Formation Mechanism in Early Stage of Cold Recycled Mixture with Emulsified Asphalt

“…According to the mixing temperature, recycling methodologies can be classified as hot recycling (HR) and cold recycling (CR) as shown in Figure 1. In HR technology, the heating temperature ranges from 120to 160°C, and the RAP content is relatively low, which is generally 10%-40% [3][4][5][6][7]. However, in CR technology, the construction process is completed under natural conditions without heating.…”

Rheological properties and engineering application of low-grade asphalt mixture

“…Low-grade asphalt is characterized by low penetration, high rigidity, and high hardness [1]. France initiated research on low-grade hard asphalt as early as the 1960s, leading to significant advancements [2,3]. In the early 21st century, the specification included the use of high modulus asphalt mixture prepared with hard asphalt.…”