Pemanfaatan fly ash batu bara sebagai filler pengganti terhadap karakteristik campuran AC-BC dengan metode pencampuran konvensional dan metode pencampuran bertahap

The development of road infrastructure has driven innovations in pavement technology, particularly in asphalt mixture techniques and the utilization of alternative materials. One of the emerging innovations is the staged mixing method, which is considered capable of improving the bond between asphalt and aggregates. Meanwhile, the limited availability of stone dust filler has encouraged the use of Class C coal fly ash from the Cilacap power plant as a potential alternative filler. This study aims to compare the effect of Class C fly ash filler substitution on the performance of Asphalt Concrete–Binder Course (AC-BC) mixtures using conventional mixing and staged mixing methods, evaluated in terms of volumetric, mechanical, and durability parameters. This research was conducted through laboratory testing, beginning with the evaluation of aggregate and asphalt material properties. The optimum asphalt content was then determined with asphalt content variations of 5%, 5.5%, 6%, 6.5%, and 7%. The AC-BC mixtures were subsequently tested using Class C fly ash substitution levels of 0%, 25%, 50%, and 75% with both mixing methods. The evaluated parameters included VITM, VMA, VFWA, stability, flow, MQ, ITS, IRS, TSR, and CL. The results indicate that the staged mixing method with Class C fly ash filler substitution provides better AC-BC mixture performance compared to the conventional method. Mixtures produced using the staged mixing method exhibited denser volumetric characteristics, higher mechanical strength, and improved durability against environmental effects and traffic loading.