Performance of hot-mix asphalt involving recycled concrete aggregates

ABSTRACT

The incorporation of recycled concrete aggregates (RCA) from construction and demolition waste (CDW) in hot-mix asphalt (HMA) could be a way to promote sustainable construction. This paper describes a laboratory study on the use of RCA in HMA for base courses in road pavements. HMA involving RCA in percentages of 0%, 5%, 10%, 20% and 30% were evaluated. To improve the moisture damage resistance of HMA made with RCA, the mixtures were cured in the oven for 4 h at a mixing temperature of 170°C, before compaction. The results indicated that the mixes made with RCA and cured for 4 h in the oven loosely fulfil the Spanish moisture damage specifications. The results also indicated that the Marshall Stability and the moisture damage resistance are substantially improved by curing the mixture in the oven. The mixtures also exhibited an adequate resistance to permanent deformation. The results from this study were highly encouraging, although HMA with RCA requires further investigation.

KEYWORDS:

• Recycled concrete aggregates
• construction and demolition waste
• hot-mix asphalt
• curing time
• moisture damage resistance
• absorbed bitumen content
• effective binder

Acknowledgments

The authors wish to acknowledge the Spanish Ministry of Education and Science for sponsoring this research through Project BIA2013-47987-C3-2-R.

The authors would also like to thank Nynas bitumen for supplying the binder required for this study, Tec-Rec for supplying the recycled aggregates, Probigasa for supplying the natural aggregates and Cosmos for supplying the Portland cement.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Spanish Ministry of Education and Science: [Grant Number BIA2013-47987-C3-2-R].