Optimization Of Mechanical Performance and Sustainability of Concrete With 50% Recycled Aggregate Through Silica Fume Slurry Treatment and Steel Fiber Reinforcement.

Construction generates a significant environmental impact, producing large amounts of construction and demolition waste (CDW). Several studies indicate that the use of recycled concrete aggregate (RCA) as a sustainable alternative for mix designs of concrete, is limited due to its notably decrease on compressive strength. This research proposes mitigating the described deficiencies through an immersion treatment of RCA in silica fume (SF) slurry and the addition of steel fibers (SFb). The results demonstrated the SF slurry immersion treatment and the addition of SFb positively affect compressive strength by 21% compared to conventional concrete and up to 46% compared to the untreated RCA mixture. However, workability was reduced to a consistency considered dry (2”) in mixtures with SFb. The increase in mechanical strength and the reduction of CO₂ emissions validates the proposal as a technical and sustainable solution.