This study examined the effect of filler ingredients on the volumetric and mechanical properties of FS 45 asphalt concrete. The purpose of this study is to investigate the effect of utilizing fly ash from a burning Asphalt Mixing Plant (AMP) on the concrete mixture. The materials consisted of split 2–3, split 1–2, sand, and cement. The sand was of the Urug type with the same variation as cement. The ratio of water-cement was 0.4 and the variations of fly ash were 0, 1.5, 3.0, 4.5, 6.0, and 7.5% of the total aggregate. The slump values ranged between 4 and 4.5 cm. This research discovered an increase in the compressive and flexural strengths of the FS 45 concrete with the addition of fly ash to the optimum point of about 3.3%. At the age of seven days, the concrete compressive strength was 425.38 kg/cm2, and at 28 days was 414.78 kg/cm2. Moreover, the optimum flexural strength was 90.07% at the age of seven days and 103.45% at 28 days. The use of fly ash aims to reduce waste discharged into the environment.