This experimental research addresses the performance of mixes developed with II/A-S 52.5 cement and recycled concrete aggregates (RCA) oriented to applications in additive manufacturing construction. Natural aggregates (NA) were replaced by RCA in different percentages (25%, 50%, 75% and 100%) in conventional and high-strength mortars. Workability was evaluated by means of flow and settlement tests. The results showed that the produced mortars with different replacement levels of NA by RAC exhibited reduced workability. This adverse effect was mitigated by increasing the superplasticizer dosage. Standard prismatic specimens and 3D-printed specimens were produced for characterizing the mechanical and the drying shrinkage properties. The results proved that increasing RCA content systematically reduced workability due to higher water absorption and surface roughness, although this effect was successfully mitigated by adjusting the superplasticizer dosage. The incorporation of RCA led to moderate strength reductions -up to 20% and 24% in conventional and high-performance mixes, respectively- yet compressive strengths above 50 MPa and 70 MPa were still achieved at 28 days, confirming the mechanical viability of these mixtures for 3D printing applications. In printed specimens, the Z-direction compressive strength (43–72 MPa) exhibited an expected anisotropy compared to molded samples, while shrinkage remained acceptable up to 75% RCA substitution but increased significantly at full replacement. Overall, the findings validate the technical feasibility of producing 3D printable mortars with RCA, highlighting their potential to reduce environmental impact without compromising performance.