Performance of eco-friendly concrete: a safe direction to sustainable cities development

Abstract

Constructing sustainable cities for the future usually encounters some challenges such as reducing the environmental footprint through using eco-friendly materials. Coarse recycled aggregate retrieved from demolished concrete structures is considered one of the eco-friendly building materials. This study aims to investigate the impact of strengthened recycled aggregate with pozzolan slurry on the different properties of concrete. Three various groups of pozzolan slurries; silica fume with fly ash, cement with fly ash, and nano-silica are used to strengthen the inferior properties of recycled aggregate. Findings showed that the proposed treatment method efficiently improved the quality of recycled aggregate. Also, this method achieved eco-friendly concrete with preferable mechanical behavior and greater resistivity against chloride diffusion. The wastage of compressive strength was 10–20%, flexural strength was 5–16%, and the elastic modulus was 13–30% of the recycled aggregate concrete in comparison with normal concrete at 28 days. By considering the application of recycled aggregate in the manufacture of new concrete, this study's results can serve as principles for achieving sustainable concrete infrastructure in the smart cities of the future.