Feasibility of using recycled concrete aggregates on half-warm mix asphalt

Abstract

[Abstract:] The present study describes a laboratory investigation on the feasibility of reusing construction and demolition waste as recycled concrete aggregate (RCA) to manufacture half-warm mix asphalt (HWMA) instead of natural aggregates. In this investigation, semi-dense HWMA for the binder course, type AC 22 bin S, was analysed. Percentages of 0 (control mixture), 55, and 100% RCA were used instead of natural aggregates (hornfels). Cationic bitumen emulsion, type C60B4, was used to manufacture the aforementioned mixtures. First, the aggregates and bitumen emulsion mixing temperatures and mixing times were determined. Subsequently, volumetric properties, water resistance, resilient modulus, and resistance to permanent deformation were determined. All the samples were manufactured using Marshall compaction. The results indicate that it was possible to dose HWMA made with 55% RCA. The mixture exhibited increased bitumen consumption when compared to that of the control mixture (0% RCA) as well as increased air void content, increased stripping potential, less stiffness, and increased rutting potential. Nevertheless, the results satisfy the required conditions for low-traffic volume roads.