CHARACTERIZATION OF RECYCLED AGGREGATE FOR USE AS BASE COURSE MATERIAL

Abstract

This study extensively evaluated the soil water characteristic curve and resilient modulus
characteristic of recycled pavement aggregate including recycled concrete aggregate (RCA), recycled asphalt
pavement (RPM), and recycled pavement material (RPM) when used as a base course in road structure. The
three recycled aggregates with similar gradation were selected for this study. The resilient modulus was
determined for each material according to NCHRP 1-28A procedure. The soil-water characteristics curves
(SWCC) were determined for each material. The major distresses including longitudinal cracking, alligator
cracking, total rutting, and International roughness index (IRI) were predicted from the Mechanistic-Empirical
Pavement Design Guide (M-EPDG). The result showed that among recycled aggregates, RPM provided the
highest for all distresses while RCA had the lowest distresses. Using recycled pavement aggregates as base
course provided lower distress than limestone which was used as a control conventional aggregate. This implied
that recycled aggregate had high quality which can use as a base course in road construction.