Defining a blockchain-verified specimen passport for 3dcp standardisation

The industrial scaling of 3D Concrete Printing (3DCP) is currently constrained by rigid prescriptive standards that cannot accommodate the complex set of interdependent process parameters, including nozzle speed, layer height, extrusion rate, print path continuity, interlayer dwell time, and curing conditions, all of which critically affect final mechanical performance (e.g., compressive strength, interlayer bond, anisotropy). Current approaches lack providing a tamper-proof, end-to-end linkage between these production parameters and mechanical outcomes within a flexible, performance-based standardisation framework. Building on the concept of digital threads in manufacturing, this paper addresses this gap by presenting a conceptual definition of a blockchain-verified 3D-Printed Concrete (3DPC) specimen passport for 3DCP. While the study remains in its preliminary stage, the passport’s data schema, smart-contract logic, and elements of integration with performance-based standardisation are specified, relegating the validation stage in a subsequent study. The 3DPC specimen passport records three core layers: the complete production process (mix design, print parameters, curing history), the resulting mechanical performance profile (strength, bond, anisotropy), and an assigned 3DCP grade corresponding to 28-days compression strength. A flexible standardisation framework is presented wherein compliance is demonstrated through the passport’s certified data rather than through fixed recipes. Blockchain and distributed ledger technologies are essential to this approach because they provide immutable, decentralised, and auditable record-keeping; without such tamper-proof verification, any performance-based system would remain vulnerable to data manipulation, disputes, and loss of trust among regulators, manufacturers, and clients. By anchoring each specimen passport on a distributed ledger, smart contracts can automatically verify performance claims and assign 3DCP grades, enabling flexible standards that adapt to process innovations while maintaining rigorous accountability. The 3DPC specimen passport is a tool for compliance and data-driven certification, available to all stakeholders including certification authorities, fostering the industrial adoption of 3DCP. This work provides a foundational reference for 3DCP standardisation based on blockchain-verified certification and performance-based standardisation.