Analysis of potential use of fibre reinforced recycled aggregate concrete for sustainable pavements

Fibre reinforced concrete (FRC) has advantages, such as minimizing cracking, increasing the composite absorption of energy and enhancing the residual strength. At the same time, the demand for sustainability led to the development of using construction and demolition waste as recycled aggregates in structural and non-structural components. The aim of this study is to analyse the technical and environmental feasibility of using fibre reinforced recycled aggregate concrete (FRRAC) in pavements. An experimental program was carried out to assess the mechanical behaviour of the FRC and FRRAC. Then, a case of study was performed to evaluate the feasibility of using FRRAC in pavements design, in which the fibre content and CO ₂ emissions (CE) were estimated for different slab thicknesses. It was observed that, to support the same design loads, slabs thicker than 0.22 m require similar fibre contents, independently of the concrete mix. Besides, it was confirmed that the CE are lower for the alternative with recycled aggregate for slab thicknesses higher than 0.20 m. In conclusion, these results open up the possibility of using FRRAC to produce more sustainable rigid pavements.