Effect of several fillers on some basic mechanical properties of asphalt concrete

Filler is one of the mandatory ingredients in asphalt mixture. It also plays a very significant role in influencing the properties and behavior of asphalt concrete. This paper presents the results of laboratory experiments to determine the influence of 4 different fillers (including conventional stone powder, Portland cement, rice husk ash, and fly ash) on some mechanical properties of asphalt concrete with Dmax of 12.5 (AC12.5). The content of filler used in the study was 5% of the total volume of aggregate. The results show that the designed AC with different fillers have the mechanical properties (air void, Marshall stability, flow, and retaining stability) that meet the specification requirements of Vietnam Ministry of Transport Decision No. 858/2014. In which the mechanical properties of AC using conventional stone powder filler are achieved with an overall better and stable effect. Although rice husk ash and fly ash filler also have certain improvements in Marshall stability and air void, AC using rice husk ash and fly ash filler does not meet the requirement of elastic modulus recommended in the Vietnam standard for flexible pavement design 22TCN 211 -06.