Experimental Investigation on Bond, Microstructure and Durability of Expired Hardened Cement Blended with Ground Granulated Blast Furnace Slag as Partial Replacement of Cement in High-Strength Concrete

The current study aimed to investigate the influence of the expired hardened cement blended with ground granulated blast furnace slag on the bond, microstructure, and durability of high-strength concrete (HSC). Five concrete mixes are prepared; the first mix is taken as a control, and the remaining four mixes are used as experimental blends. HSC characteristics are evaluated by compressive, flexural, splitting tensile, bond, and durability tests. Furthermore, the ultrasonic pulse velocity and microstructural characteristics tests are carried out to check concrete quality. The synergistic action of blends (expired harden cement with GGBS) on the strength test results was found to increase with an increase in blends up to 20%. The durability result reveals that HSC was found to be impermeable under aggressive conditions. The microstructural characteristics achieved in the current investigation explain the above strength, bond, and durability performance of these mixes. The whole performance of blends in HSC is adequate for industrial use.