Effect of accelerated curing in slag based high performance nano concrete

This article presents the impact of accelerated curing on high-strength, high-performance nano concrete made from copper slag. The study utilized a combination of cement and silica fume nanoparticles as binders, with quartz powder particles acting as fillers. Industrial by-products from the copper smelting industry were used to replace traditional fine and coarse aggregates, promoting sustainability. To enhance the tensile strength and flexural stiffness of the concrete, micro steel fibers were incorporated based on the optimal design mix for compressive strength. Both conventional and accelerated curing methods were adopted during preparation of the specimen. Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) analyses were conducted on the optimal nano concrete blends to investigate their microstructure. The developed concrete was evaluated for various structural applications, incorporating micro steel fibers and nanofibers. The highest compressive strength achieved with 100% sand replacement by copper slag was 136 MPa under accelerated curing conditions. Flexure, direct tension, and split tension tests yielded maximum values of 11.78 MPa, 7.12 MPa, and 12.70 MPa, respectively. Nano-Concrete elements reinforced with a blend of carbon and steel fibers exhibited greater flexural capacity, along with delayed crack initiation and propagation. Accelerated curing facilitated the growth and uniform distribution of C-S-H gel, further improving the performance of the nano-concrete.