Assembling reinforcing bar is one of the slowest and most labor-intensive tasks in reinforced concrete construction. Furthermore, when design requirements dictate complex and congested reinforcement for concrete elements, constructability and concrete quality can be compromised with potential implications on the capacity of a structure. The goal of this BRITE Pivot project is to understand the fundamental structural behavior and constructability of optimized and additively manufactured (also known as 3D printed) steel reinforcement for concrete structural elements that are prone to reinforcement congestion. This novel reinforcing steel will lead to automation, high construction quality, speed, reduced reliance on manual labor, elimination of reinforcing bar congestion, and structural efficiency. The findings of this project will enable engineers to think beyond grid-like reinforcement layouts and re-imagine reinforcement as a freeform structure tailored to function. The project will allow the principal investigator to gain knowledge on mechanical properties and processes of additively manufactured steel to transfer it to structural engineering for advancing reinforced concrete design, construction, and response. The project will study topologically optimized, free-form, additively manufactured steel reinforcement for concrete lateral load resisting elements that undergo load reversals. Shear wall coupling beams that often require challenging-to-build reinforcement in diag