Performance of Hot Mix Asphalt Concrete Produced with Coarse Recycled Concrete Aggregate

Abstract

This paper evaluates the replacement of natural aggregate coarse fraction for recycled concrete aggregate (RCA) in hot mix asphalt (HMA) concrete production, an area in which studies are recent and scarce. Crushed stone coarse aggregates (CSCA) were replaced by RCA with a 30 MPa compressive strength in the following percentages: 0, 25, 50, 75, and 100%, and mixed with asphalt cement (AC) 50-70. Volumetric and mechanical properties resulting from the Marshall mix design method, along with permanent deformation and durability by the moisture-induced damage test (Lottman), were analyzed. The results indicate that, although RCA shows higher absorption, higher Los Angeles abrasion, and lower density than the crushed stone aggregates, the mixtures showed satisfactory results for use as an asphalt concrete surface layer on low-volume roads. Wheel tracking tests presented permanent deformations ranging between 4.4 and 9.3%. It was also perceived as an adhesiveness improvement in the RCA mixture. The results reinforce the need to seek alternatives to reduce the binder consumption when coarse RCA is used in HMA production.