The influence of fine recycled asphalt pavement aggregates on the properties of self-compacting mortar in fresh and hardened state

Sustainable development is a contemporary concern in the field of asphalt pavements, as road construction consumes a significant amount of new aggregates. Furthermore, road maintenance necessitates the milling of old pavement layers, which generates a substantial quantity of bituminous material waste. This study explores the use of recycled sand from asphalt waste as a substitute for 0, 25, 50, 75, and 100% of natural sand in self-compacting mortar, aiming to achieve both sustainable and economical asphalt production. The differences in physical properties between natural sand (NS) and fine recycled asphalt pavement (FRAP) aggregates are analyzed and compared. The characteristics of the various self-compacting mortars are measured, including spread, flow time, as well as compressive and tensile strength, shrinkage and sorptivity. Compared to the control mortar, the mortars containing RPAS exhibit a rougher surface, additional pores, and more complex pore structures. The need for superplasticizers increases with the substitution rate, as do the rheological parameters. The results indicate that recycled mortar can be an alternative to natural sand, although this comes with negative impacts on the mechanical properties of the mortar. Nonetheless, these effects can be mitigated when considering their economic and environmental implications.