High-performance eco-friendly concrete with improved strength, chloride ion penetration, and corrosion resistance by the high volume of Ground Granulate Blast Furnace Slag (GGBS)

The present research aims to manufacture concrete that meets compressive strength parameters, has the lowest environmental impact, and resists chloride ion penetration and corrosion. This study used varied volumes of cement replacement with slag (GGBS) (30, 40, and 50)% by mass of cement for two concrete classes, C30 and C40. Fresh tests (slump, initial and final setting time), hardening (compressive, splitting, and flexural strength), and durability (porosity, water absorption, density, penetration depth, chloride ion migration coefficient, electrical resistivity, corrosion rate, mass loss, crack width due to corrosion, and microstructure analysis) were performed.

The environmental impact of concrete components in each mix was also assessed. The impressed current technique increased rebar corrosion in concrete specimens immersed in 5% sodium chloride. Replacing cement with GGBS by 30–50% increased the setting time and enhanced all hardening qualities. Mechanical qualities improved most at 40% GGBS, with C30 mixes' compressive, tensile, and flexural strengths up 29.3%, 38.7%, and 15.8% at 90 days. Compare 21.3%, 19.2%, and 16.2% at 90 days for C40 combinations to the reference mixture. Strength reduced marginally at 50% GGBS but remained greater than the reference blend. However, a 50% GGBS replacement rate best-improved durability, microstructure, and environmental efficiency. The C30-50% GGBS mixture is ideal because it met the design requirements of C30 and C40, had the best improvement in porosity and water absorption, the slightest chloride penetration, and the best performance against corrosive environments of the six mixtures except C40-50% GGBS. Additionally, it is the least environmentally harmful combination.