2026 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2026): 3D Printed Concrete
Program Organizers: David Leigh, University of Texas at Austin
Tuesday 8:00 AM
August 4, 2026
Room: Zlotnick Ballroom 1
Location: AT&T Center
Session Chair: Iris Rivero, University of Florida
8:00 AM
Smart 3D-Printed Concrete Beam for Real-Time Deformation Monitoring: Moneef Mohamed Elobaid Musa1; Pushp Raj Poudel1; Israel Nilton Lopes Sousa2; Ben W Johnson1; Shelby Doyle1; Antonella D’Alessandro2; Filippo Ubertini2; Iris V. Rivero3; Simon Laflamme1; 1Iowa State University; 2University of Perugia; 3University of Florida
Recent advances in additive manufacturing have created new opportunities for concrete constructions, improving design freedom, accelerating fabrication, and reducing reliance on conventional formwork. However, the reliability of 3D-printed cementitious components remains limited by process- induced uncertainties, particularly those associated with layer-wise deformation, interlayer bonding, and material heterogeneity during deposition. These challenges are strongly governed by key printing parameters and continue to hinder large-scale implementations. This study investigates a 3D-printed smart beam concept designed to self-sense structural conditions during fabrication. The sensing functionality is achieved through the incorporation of functionalized layers fabricated by incorporating graphite powder and carbon microfibers within the cementitious mix that boosts the material’s piezoresistive behavior. This work studies how the smart beam’s signal can be leveraged to conduct quality control and quality assessment during the print. Results demonstrate that the electrical signal can be combined with a digital twin to track the layering process.
8:20 AM
Effects of Mix Design on Shrinkage of 3D Printed Concrete: Artem Egorov1; Taylor Rawlinson1; Christopher Ferraro1; Kyle Riding1; 1University of Florida
This study examined the effects of adjusting proportions of water, cement, fine and coarse aggregates, shrinkage-reducing and -compensating admixtures, as well as metakaolin (MK) calcined clay, on the shrinkage of 3D printed concrete (3DPC). Printable mixes were first developed using an in‑situ caulk gun extrusion test and the modified ASTM C1437 slump flow test. Buildability was further evaluated using unconfined compression to obtain time-dependent green strength and Young’s modulus, revealing that MK mixes gained strength rapidly compared to control concrete and mortar mixes. Unrestrained shrinkage was measured using 3 in. × 3 in. prisms via a modified ASTM C157. MK mixes showed high early shrinkage but significantly reduced long‑term shrinkage relative to other designs. ASTM C157 failed to capture the shrinkage‑reduction effect of shrinkage-compensating admixtures. This study proposes using ASTM C1581 in future work to quantify the effects of these admixtures.Keywords: 3D printed concrete (3DPC), metakaolin (MK), calcined clay, shrinkage-reducing/-compensating admixture, slump flow, buildability, drying shrinkage.
8:40 AM
Benchmarking Fixtures for Additive Construction: Shawn Platt1; 1National Institute of Standards and Technology
Concrete Additive Construction (CAC) is an emerging technology with the potential to revolutionize the construction industry. Once the print process begins, it is essential to evaluate the performance of the equipment and the material before investing in the larger structure. The geometric accuracy of CAC structures is limited by the inherent nature of the extrusion process and predefined layer thickness. As each layer is deposited, the layer beneath it initially undergoes elastic deformation before potentially developing some plastic deformation under the weight of subsequent layers. While standardized test fixtures have historically played a vital role in assessing process performance in various segments of additive manufacturing (AM), there is currently a lack of standard test fixtures for Additive Construction (AC). The findings of this research provide insight into the significance of standardized test fixtures in advancing CAC technology and promoting its integration within the construction industry.
9:00 AM
Influence of Process Parameters on Mechanical Strength and Durability of 3D Printed Concrete (3DPC): Tor Slowe1; Andrea Camacho-Betancourt1; Iris Rivero1; 1University of Florida
Understanding how process parameters influence the strength and durability of concrete-printed infrastructure is integral for commercial advancement. Minimal research has examined process quality methodologies beyond mortar mix design. This study focuses on large-scale 3DPC using coarse aggregate, reducing costly and carbon-intensive cement while maintaining structural performance. Including large aggregates increases sensitivity to process timing, extrusion conditions, and particle segregation, promoting void formation and weak interlayer interfaces if parameters are not properly selected. This research assesses multilayer samples produced under controlled parameter specifications (nozzle height, nozzle velocity, extrusion rate, layer time, and stiffener flow rate) to determine bond strength and durability, via interlayer tensile and shear strength tests and pore geometry, respectively. Analysis of durability will elucidate the mechanical properties of filament bonds and guide future mitigation. Findings indicate extrusion rate and layer time strongly affect strength and porosity, providing insight into parameter-driven defect formation for reliable and repeatable large-scale 3DPC.
9:20 AM
Embedded Sensors for Intelligent Additive Manufacturing of Concrete Structures: Stan Farnsworth1; 1NextFlex
Additive manufacturing of concrete structures presents significant opportunities for automation, material efficiency, and design flexibility, but broader adoption may depend on improved process monitoring, structural validation, and lifecycle performance assessment. The author proposes the integration of embedded electronic sensors as a foundation for intelligent, data-driven concrete construction systems. Sensors incorporated within deposition equipment could monitor material properties such as moisture content, pH, temperature, and flow consistency to support process optimization and future digital twin development. Sensors embedded directly within printed concrete structures may enable monitoring of curing behavior, interlayer bonding quality, strain development, and crack initiation throughout the life of the structure. Additional opportunities include thermal and environmental sensing to support smart-building energy management. The proposed sensing approaches could provide quantitative evidence of structural quality, durability, and operational performance, thereby increasing public, regulatory, and investor confidence in additively manufactured concrete structures.
9:40 AM Break
10:00 AM Panel Discussion