The use of recycled coarse aggregate (RCA) in concrete helps the environment by using fewer natural resources and reducing the amount of trash in landfills. Nevertheless, RCA coarse is generally less strong and more porous because of the adhesion of mortar and a suboptimal interfacial transition zone (ITZ). This study employed recycled coarse aggregate (RCA) to examine the feasibility of employing graphene oxide (GO) to serve as a nano-engineered additive to improve concrete’s microstructural and mechanical properties. The creation of an M30-grade concrete mix using 100% RCA and M-sand was the main goal of the current investigation, whereby GO was added at a ratio of 0.02%–0.06% of the cement weight. Using SEM, EDS, FTIR, TGA, and micro-CT scanning, we investigated microstructure and mechanical characteristics, such as compressive, split tensile, and flexural strength. The results show that the inclusion of GO significantly improves both ITZ compaction and strength development. The most desirable effect was realized using 0.04% GO. The microstructure study indicated that the crack-bridging and nucleation actions of GO resulted in decreased porosity, improved pore distribution, and strengthened aggregate–cement bonding. These findings reveal that GO can overcome challenges associated with RCA concrete, paving the way for better quality and more stable construction materials.
S. et al. (Tue,) studied this question.