Effect of Collision Variation towards the Index Retained Strength of Mixed Asphalt Concrete Wearing Course

Compaction of Asphalt Concrete Wearing Course (AC-WC) is a compression process in order to obtain sufficient strength and stability and cavity in the asphalt mixture. The compaction process in the field is carried out using a tandem roller, whereas for the design of the mixture in the laboratory, the compaction process is simulated by weighing the mixture in the mold. Collision that does not meet the requirements can cause the density of the asphalt mixture to be uneven and easily cracked which will ultimately affect the performance of the asphalt mixture produced, both in terms of service life and in terms of comfort. This research will examine the effect of different amounts of collision during the compaction process on the characteristics of the AC-WC mixture by taking the number of collisions of 25x, 50x and 75x by varying the asphalt content of 5%, 5.50%, 6%, 6.50% and 7%. The results showed that using a mixture composition of 39.9% coarse aggregate, 46.8% fine aggregate, 6.30% filler and 7% asphalt and collision 25 collisions, 50 collisions, 75 collisions, AC-WC mixture was resistant to the effects of collisions and the effect of water immersion where the VFB value increases and the VMA value decreases. The Retained Strength Index shows all variations of collisions that meet the standard specifications.