Validation of the Super Air Meter for 3D Printed Mortar: Correlation of SAM Number, Spacing Factor, and Freeze–Thaw Durability with Identification of Threshold Values
Presented By: Moein Mousavi
Affiliation:
Description: The air-void system plays a critical role in the freeze–thaw durability of cementitious materials and is traditionally characterized using hardened-state techniques such as ASTM C457. The Super Air Meter (SAM), based on a modified ASTM C231, has been proposed as a rapid field method to assess air-void quality in fresh concrete. While SAM has been validated for conventional concrete containing coarse aggregate, its applicability to mortar-based systems and 3D printed concrete remains largely unexplored. This study investigates the validity of SAM for mortar mixtures with varying air-entraining agent (AEA) dosages. Both cast and 3D printed specimens were produced using identical mixtures to isolate the effect of placement method. Fresh-state measurements included air content and SAM number, while hardened specimens were evaluated using digital image analysis to determine spacing factor, total air, and specific surface. Freeze–thaw performance was evaluated using a modified ASTM C666 procedure. Established relationships between SAM number, spacing factor, and durability in conventional concrete were used as a baseline to evaluate their validity for mortar systems. Correlations among SAM number, spacing factor, and durability factor were developed for both cast and 3D printed specimens. These results were used to assess the applicability of existing criteria and to identify potential SAM threshold and spacing factor values corresponding to adequate durability in 3D printed mortar systems. The results provide new insight into appropriate SAM threshold and spacing factor values for 3D printed mortar to achieve acceptable freeze–thaw durability, thereby supporting ongoing standardization efforts for additive manufacturing in concrete.
The Development of Two Test Methods for Measuring Bond Strength in Additive Concrete Construction
Presented By: Ladson Brearley
Affiliation: Applied Research Transformation, Pllc
Description: Bond strength is a governing parameter in the structural performance of additively constructed concrete (ACC), controlling interlayer integrity, load transfer, durability, and overall anisotropic behavior. Unlike conventionally cast concrete, ACC is inherently sensitive to process-induced variables that influence bond development between layers.
This presentation reviews the fundamental mechanisms of interlayer bond strength in ACC, emphasizing key factors such as material properties, printing processes, surface conditions, interlayer time interval, and environmental exposure. It then presents the development of two ASTM standard test methods designed to mechanically quantify bond strength: a four-point flexural test and a splitting tensile test. These methods provide practical and repeatable approaches for characterizing interlayer bond performance in printed concrete elements.
Results from an interlaboratory study conducted by the Additive Construction by Extrusion (ACE) Consortium are presented with data from multiple laboratories analyzed to assess repeatability, reproducibility, and sources of variability in both methods.
This work advances the standardization of bond strength testing in ACC, supporting improved quality control, material qualification, and structural design practices.
Advancing Codes and Standards for Additively Constructed Concrete: Insights from Recent Structural Testing
Presented By: David Langefeld
Affiliation: ICON Technology, Inc.
Description: Codes and standards for additive construction are in development. They will benefit from continued construction-scale research and structural testing to enhance the understanding of the systems these codes and standards aim to regulate. This presentation examines recent structural testing programs conducted to support product approval and code development for 3D-printed concrete wall systems, including seismic shake table testing, shear and flexural testing, and post-installed mechanical anchor testing. Results from these programs offer direct insight into the behavior of printed wall assemblies and components that are beneficial to ongoing codes and standards development efforts.
International Code Councils new consensus standard for Automated Construction Technology for 3D Printing Walls (ICC 1150)
Presented By: Bora Gencturk
Affiliation: University of Southern California
Description: This presentation provides a comprehensive overview of the newly published International Code Council (ICC) 1150—2026 Standard for 3D Automated Construction Technology for 3D Concrete Walls, the first consensus-based standard of its kind for 3D-printed wall systems. Developed over more than two years through an ANSI-accredited consensus process involving extensive public committee engagement, ICC 1150 establishes minimum requirements to safeguard public health, safety, and welfare while enabling the use of emerging automated construction technologies. ICC 1150 represents a significant milestone in the advancement of construction-scale additive manufacturing by providing a unified framework that addresses the full lifecycle of 3D-printed wall systems. The standard includes provisions for material specifications and laboratory prequalification, including testing methods for fresh properties, strength, durability, and fire performance. It further establishes structural design requirements for gravity, wind, and seismic loading (currently limited to Seismic Design Categories A and B), along with detailed criteria for reinforcement, including vertical and horizontal reinforcement, bond beams, headers, and detailing at openings, intersections, and load transfer elements. In addition, the standard defines requirements for connections between 3D-printed walls and other structural components, as well as field prequalification testing, construction quality assurance, and special inspection protocols. Together, these provisions provide a consistent and enforceable basis for design, evaluation, and construction using 3D automated construction technology. This presentation will walk through the key technical components of ICC 1150, highlighting its structure, underlying design philosophy, and practical implications for engineers, code officials, material suppliers, and construction professionals seeking to implement 3D-printed wall systems in compliance with modern building code
3DCP Materials Prequalification, Field Testing, Acceptance, and Trouble Shooting for 3D Printing Walls
Presented By: Bing Tian
Affiliation: The Quikrete Companies
Description: Understanding the prequalification, field testing, and acceptance of 3DCP Products used for 3D Printing Walls. Trouble shooting if there is any discrepancy between the submitted materials and the specification.