Recycling shredded waste cigarette butts as stabilising fibres in stone mastic asphalt concretes

Considering the global burden of cigarette consumption, the disposal of cigarette butts has become an inevitable issue. Compared to traditional disposal methods, such as landfilling or incinerating, the recycling of these wastes is clearly an eco-friendlier solution. In this research, waste electronic cigarette butts (E-CBs) were collected and recycled in bituminous mixtures, aiming to increase the use of sustainable road construction materials. The objective of this research is to explore the possibility of using waste E-CBs as an alternative stabilising fibre in asphalt mixtures. To this end, shredded waste E-CBs were incorporated in Stone Mastic Asphalt (SMA) and compared with the conventional cellulose fibres. Furthermore, to investigate the effects of powders (below 0.063 mm) from the waste E-CBs on the rheological properties of bitumen, tests were conducted on base SBS-modified bitumen and its mastics. Results show that the waste powder was unfavourable to the thermal susceptibility of the resulting binder. SMA samples with shredded E-CBs were also characterised through physical and mechanical tests and compared to the reference mixture using cellulose fibres. It was concluded that using waste E-CBs in SMA can be considered a promising alternative for replacing cellulose fibres and avoiding the disposal of cigarette butts.