Behaviour of eco-friendly mortar containing recycled concrete sand in fresh and hardened states

The use of recycled concrete aggregates (RCA) is one of the solutions to the problems of both the high demand for natural aggregates by the construction industry and the reduction of landfill demolition debris overload. However, the production of concrete or mortar based on RCA with qualities similar to those made with natural aggregates (NA) poses challenges. The main objective of this experimental study is to determine the influence of replacing 20%, 40%, and 60% of natural sand (NS) with recycled concrete sand (RCS) on the mechanical and physical properties of eco-friendly mortar. The results obtained revealed that RCS, rich in attached mortar, exhibits low physical properties such as low density, rough grain shape, and highwater absorption. Regarding the mechanical behaviour of the mortar produced, the results show that the presence of RCS has a positive impact on the compressive strength (Sc). However, it has a negative effect on shrinkage.