Chmelnizkij, AlexanderAlexanderChmelnizkijVollmert, JasperJasperVollmertPaetzold, PhilippPhilippPaetzoldGrün, JohannesJohannesGrünHagemann, JohannesJohannesHagemannDora, JohannesJohannesDoraSchropp, AndreasAndreasSchroppDragos, KosmasKosmasDragosSmarsly, KayKaySmarsly2026-07-242026-07-242026-0626th International Conference on Computational Science, ICCS 2026https://hdl.handle.net/11420/63984Clay-based 3D printing has emerged as a low-carbon alternative to cementitious additive manufacturing in construction. However, pore space, inhomogeneities, shrinkage, and crack formation in clay-sand-water mixtures are still poorly understood, particularly with respect to their influence on the structural integrity of clay-printed elements. This paper investigates the use of X-ray computed tomography (CT) for specimen-scale analysis of clay-sand-water mixtures used in additive manufacturing. One printed specimen and two manually prepared reference specimens in the wet and dried state were scanned with the ENCI CT system. The reconstructed and segmented volumes were used to quantify pore volume, equivalent spherical diameter, sphericity, a derived specific pore surface, and spatial porosity distribution. The printed sample exhibited markedly smaller pores than the manually prepared dried sample, indicating compaction during extrusion and layer deposition, while the dried sample showed larger and more crack-like pores consistent with shrinkage during drying. Local porosity maps and their coefficients of variation were further used to identify heterogeneous zones that may act as mechanically weaker regions. The results demonstrate the feasibility of CT-based assessment for characterizing internal porosity and heterogeneity in 3D-printed clay elements.en3D clay printingdensity distributionporositystructural integrityX-ray computed tomographyTechnology::620: EngineeringTechnology::620: Engineering::620.1: Engineering Mechanics and Materials ScienceTechnology::624: Civil Engineering, Environmental EngineeringTechnology::624: Civil Engineering, Environmental Engineering::624.1: Structural EngineeringConference Paper10.1007/978-3-032-29921-5_36