Properties of modified asphalt mixtures with additives of fillers materials

Abstract

In past, the use of by-product materials such as cement kiln dust and fly ash powders, especially in the field of highway pavements has received increasing attention. The aim of this research is to investigate the physical properties of the modified asphalt binder with additives of filler types such as cement kiln dust, fly ash, and metakaolin powder. Then, to assess the Marshall properties of modified asphalt mixtures. Three fillers containing 3%, 5%, and 7% by weight were used. The modified asphalt binder was mixed by a mechanical mixer having a revolution rate of (2000 rpm.), for mixing time (5 to 20) min. at a temperature of 140 °C. Results showed that the use the additives was beneficial in improving the physical characteristics of the asphalt cement. Overall, it was found that the penetration grade reduced and softening point values increased and the susceptibility of temperature was enhanced. Furthermore, the results of the tested specimens, the 5% of CKD, 5% of fly ash and 7% of MK were sufficient to improve the physical characteristics and Marshall properties of modified asphalt binder mixtures. In addition, the results obtained from the Marshall test show that the maximum stability for 7% of MK, 5% of CKD, 5% of fly ash, and control asphalt mixtures are (14.4, 13.6, 11.7 and 10.4) kN, respectively.