Potential of recycled fine aggregates powder as filler in asphalt mixture

The main objective of this study is to investigate the potential of using recycled fine aggregates powder (RFAP) as filler in asphalt mixtures. RFAP is a by-product of the production of Recycled Concrete Aggregate (RCA). The disposal of RFAP may cause many serious environmental problems. It is necessary to find potential usage to avoid these problems.In this study, RFAP is used as filler in asphalt mixture by totally replacing conventional limestone powder (LP). Firstly, the properties of RFAP is studied by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). Then the indirect tensile strength and modulus tests, three-point bending tests, dynamic creep tests and fatigue tests are conducted to compare the properties between asphalt mixtures with RFAP and traditional asphalt mixture with LP. Results indicate that RFAP can improve the properties of asphalt mixture, such as including water sensitivity and fatigue resistance. However, it may cause a little decrease of the low-temperature performance. All the results indicate that the RFAP can be used in asphalt pavement, especially in hot regions.

► Recycled fine aggregate can be recycling as filler in asphalt mixture.
► Recycled fine aggregate powder particles is rougher than that of limestone powder.
► The RFAP used as filler in asphalt mixture improve its performance.