Performance of Asphalt Concrete Wearing Course (AC-WC) Utilizing Reclaimed Asphalt Pavement from Cold Milling Bound with 80/100 Pen Asphalt

Abstract

Demands on natural aggregate materials for road pavement can be reduced by utilizing reclaimed asphalt pavement (RAP). This research was aimed at evaluating the performance of AC-WC mixture using RAP materials from cold milling, bound with 80/100 pen asphalt. The RAP aggregate gradation was adjusted by adding the required amount of natural aggregates to meet the specification in Indonesia. The RAP and added aggregates were hotmixed and compacted with Marshall hummer at 2×75 blows. The asphalt content were varied. It was found that the optimum asphalt content was 6.05 % with the following Marshall characteristics: stability 1237.08 kg; flow 3.36 mm; Marshall quotient 324,73kg/mm; void in mix (VIM) 3,360%; void in mineral aggregate (VMA) 15.103; and void filled with bitumen (VFB) 77.759% and residual stability 91.04; all met the Indonesian specification. The cantabro abration loss (CAL) at 30°C was 9,02%. The indirect tensile stiffness modulus (ITSM) at 20 °C was 7961.4 MPa; dynamic creep with 100 kPa pressure at 40°C gave slope 0.0112 microsstrain/pulse which is suitable for heavy load traffic. The fatigue test results was obtained at increased stress level, i.e. at 900, 1100, and 1300 kPa. Based on the equation derived from the fatigue strain and repeated loading relationship, at 100 microstrain (με) the repeated load was 434,661.58 times, and at one million (106) repeated loading, the samples could withstand strain of 92,38 microstrain. The performance of the samples were overall better than AC-WC mixture using virgin aggregates bound with 60/70 pen asphalt.