{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T10:38:57Z","timestamp":1776940737415,"version":"3.51.4"},"reference-count":49,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T00:00:00Z","timestamp":1755216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004569","name":"Ministry of Science and Higher Education","doi-asserted-by":"publisher","award":["DWD\/5\/0237\/2021"],"award-info":[{"award-number":["DWD\/5\/0237\/2021"]}],"id":[{"id":"10.13039\/501100004569","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Three-dimensional concrete printing (3DCP) is an emerging additive manufacturing technology with increasing application potential in the construction industry, offering advantages such as reduced labor requirements, shortened construction time, and material efficiency. However, structural integrity remains a challenge, particularly due to weak interlayer bonding resulting from the layered manufacturing process. This study investigates the mechanical performance and anisotropy of 3D-printed mineral-based composites with respect to the time interval between successive layers. Specimens were printed with varying interlayer intervals (0, 25, and 50 min) and tested in different loading directions. Flexural, compressive, and tensile strengths (direct and splitting methods) were measured both parallel and perpendicular to the layer orientation. Results showed a clear degradation in mechanical properties with increasing interlayer time, particularly in the direction perpendicular to the layers. Flexural strength decreased by over 25% and direct tensile strength by up to 40% with a 25 min interval. Compressive strength also declined, though less dramatically. Compared to cast specimens, printed elements showed 3\u20134 times lower compressive strength, highlighting the significant impact of interlayer cohesion. This study confirms that both the time between layers and the loading direction strongly influence mechanical behavior, underlining the anisotropic nature of 3DCP elements and the need for process optimization to ensure structural reliability.<\/jats:p>","DOI":"10.3390\/ma18163845","type":"journal-article","created":{"date-parts":[[2025,8,15]],"date-time":"2025-08-15T16:09:55Z","timestamp":1755274195000},"page":"3845","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Anisotropy of Mechanical Properties of 3D-Printed Materials\u2014Influence of Application Time of Subsequent Layers"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6554-4613","authenticated-orcid":false,"given":"Marcin","family":"Maroszek","sequence":"first","affiliation":[{"name":"Department of Materials Engineering, Faculty of Materials Engineering and Physics, Cracow University of Technology, Warszawska 24, 31-155 Krak\u00f3w, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2852-8934","authenticated-orcid":false,"given":"Izabela","family":"Hager","sequence":"additional","affiliation":[{"name":"Chair of Building Materials Engineering, Faculty of Civil Engineering, Cracow University of Technology, Warszawska 24, 31-155 Krak\u00f3w, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5306-2035","authenticated-orcid":false,"given":"Katarzyna","family":"Mr\u00f3z","sequence":"additional","affiliation":[{"name":"Chair of Building Materials Engineering, Faculty of Civil Engineering, Cracow University of Technology, Warszawska 24, 31-155 Krak\u00f3w, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6219-3256","authenticated-orcid":false,"given":"Mateusz","family":"Sitarz","sequence":"additional","affiliation":[{"name":"Chair of Building Materials Engineering, Faculty of Civil Engineering, Cracow University of Technology, Warszawska 24, 31-155 Krak\u00f3w, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8583-9459","authenticated-orcid":false,"given":"Marek","family":"Hebda","sequence":"additional","affiliation":[{"name":"Department of Materials Engineering, Faculty of Materials Engineering and Physics, Cracow University of Technology, Warszawska 24, 31-155 Krak\u00f3w, Poland"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Al-Tamimi, A.K., Alqamish, H.H., Khaldoune, A., Alhaidary, H., and Shirvanimoghaddam, K. (2023). Framework of 3D Concrete Printing Potential and Challenges. Buildings, 13.","DOI":"10.3390\/buildings13030827"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"100344","DOI":"10.1016\/j.dibe.2024.100344","article-title":"Towards Full Automation in 3D Concrete Printing Construction: Development of an Automated and Inline Sensor-Printer Integrated Instrument for in-Situ Assessment of Structural Build-up and Quality of Concrete","volume":"17","author":"Rehman","year":"2024","journal-title":"Dev. Built Environ."},{"key":"ref_3","unstructured":"Home Innovation Research Labs (2023). 3D Concrete Printed Construction Systems Part 1: Identifying Barriers and Opportunities Market Research Findings\u2014Final Report."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"995","DOI":"10.1016\/j.matpr.2022.03.619","article-title":"Applications, Performance, Challenges and Current Progress of 3D Concrete Printing Technologies as the Future of Sustainable Construction\u2014A State of the Art Review","volume":"65","author":"Rollakanti","year":"2022","journal-title":"Mater. Today Proc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.autcon.2006.05.002","article-title":"Freeform Construction: Mega-Scale Rapid Manufacturing for Construction","volume":"16","author":"Buswell","year":"2007","journal-title":"Autom. Constr."},{"key":"ref_6","first-page":"101823","article-title":"Biomimicry for 3D Concrete Printing: A Review and Perspective","volume":"38","author":"Babafemi","year":"2021","journal-title":"Addit. Manuf."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"670","DOI":"10.1016\/j.conbuildmat.2018.04.017","article-title":"3D Printing of Earth-Based Materials: Processing Aspects","volume":"172","author":"Perrot","year":"2018","journal-title":"Constr. Build. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Dvorkin, L., Marchuk, V., Mr\u00f3z, K., Maroszek, M., and Hager, I. (2024). Energy-Efficient Mixtures Suitable for 3D Technologies. Appl. Sci., 14.","DOI":"10.3390\/app14073038"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"01002","DOI":"10.1051\/matecconf\/201816301002","article-title":"Evaluation of Suitability for 3D Printing of High Performance Concretes","volume":"163","author":"Hoffmann","year":"2018","journal-title":"MATEC Web Conf."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1108\/RPJ-01-2021-0009","article-title":"Additive Manufacturing a Powerful Tool for the Aerospace Industry","volume":"28","author":"Khorasani","year":"2022","journal-title":"Rapid Prototyp. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1717","DOI":"10.1108\/RPJ-11-2021-0307","article-title":"Additively Manufactured Thermoplastic Polyurethane (TPU) Mold for Concrete Casting of Complex Structure","volume":"28","author":"Xu","year":"2022","journal-title":"Rapid Prototyp. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1312","DOI":"10.1108\/RPJ-07-2021-0160","article-title":"A Critical Review of 3D Printing and Digital Manufacturing in Construction Engineering","volume":"28","author":"Ali","year":"2022","journal-title":"Rapid Prototyp. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"100378","DOI":"10.1016\/j.dibe.2024.100378","article-title":"Concrete 3D Printing Technology for Sustainable Construction: A Review on Raw Material, Concrete Type and Performance","volume":"17","author":"Wang","year":"2024","journal-title":"Dev. Built Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"133364","DOI":"10.1016\/j.conbuildmat.2023.133364","article-title":"3D Printing Concrete Structures: State of the Art, Challenges, and Opportunities","volume":"405","author":"Liu","year":"2023","journal-title":"Constr. Build. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"106386","DOI":"10.1016\/j.cemconres.2021.106386","article-title":"Investigation of Interlayer Adhesion of 3D Printable Cementitious Material from the Aspect of Printing Process","volume":"143","author":"Weng","year":"2021","journal-title":"Cem. Concr. Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"127114","DOI":"10.1016\/j.conbuildmat.2022.127114","article-title":"Rheological Properties and Compressive Strength of Construction and Demolition Waste-Based Geopolymer Mortars for 3D-Printing","volume":"328","author":"Ilcan","year":"2022","journal-title":"Constr. Build. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Nerella, V.N., and Mechtcherine, V. (2019). Studying the Printability of Fresh Concrete for Formwork-Free Concrete Onsite 3D Printing Technology (CONPrint3D). 3D Concrete Printing Technology, Elsevier.","DOI":"10.1016\/B978-0-12-815481-6.00016-6"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"105863","DOI":"10.1016\/j.jobe.2023.105863","article-title":"A Review of \u201c3D Concrete Printing\u201d: Materials and Process Characterization, Economic Considerations and Environmental Sustainability","volume":"66","author":"Ahmed","year":"2023","journal-title":"J. Build. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Maroszek, M., Rudziewicz, M., Hutyra, A., Dziura, P., and Hebda, M. (2024). Evaluation of 3D Concrete Printing Extrusion Efficiency. Appl. Sci., 14.","DOI":"10.3390\/app142411866"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"127201","DOI":"10.1016\/j.jclepro.2021.127201","article-title":"Sustainability Tradeoffs in the Adoption of 3D Concrete Printing in the Construction Industry","volume":"307","author":"Adaloudis","year":"2021","journal-title":"J. Clean. Prod."},{"key":"ref_21","unstructured":"Diks, T. (2019). The Roadmap to Standards for 3D Concrete Printing: Research on the Interplay Between Technological and Legislative Developments. [Bachelor\u2019s Thesis, University of Twente]."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"108563","DOI":"10.1016\/j.engfracmech.2022.108563","article-title":"The Theory of Critical Distances to Assess the Effect of Cracks\/Manufacturing Defects on the Static Strength of 3D-Printed Concrete","volume":"269","author":"Alanazi","year":"2022","journal-title":"Eng. Fract. Mech."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Marchment, T., Sanjayan, J.G., Nematollahi, B., and Xia, M. (2019). Interlayer Strength of 3D Printed Concrete. 3D Concrete Printing Technology, Elsevier.","DOI":"10.1016\/B978-0-12-815481-6.00012-9"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"33","DOI":"10.21809\/rilemtechlett.2019.84","article-title":"Surface Modification as a Technique to Improve Inter-Layer Bonding Strength in 3D Printed Cementitious Materials","volume":"4","year":"2019","journal-title":"RILEM Tech. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"586","DOI":"10.1016\/j.conbuildmat.2019.01.235","article-title":"Effects of Layer-Interface Properties on Mechanical Performance of Concrete Elements Produced by Extrusion-Based 3D-Printing","volume":"205","author":"Nerella","year":"2019","journal-title":"Constr. Build. Mater."},{"key":"ref_26","unstructured":"Lao, W., Li, M., Masia, L., and Tan, M.J. (2025, January 10\u201313). Approaching Rectangular Extrudate in 3D Printing for Building and Construction by Experimental Iteration of Nozzle Design. Proceedings of the Annual International Solid Freeform Fabrication Symposium, Austin, TX, USA."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"105154","DOI":"10.1016\/j.cemconcomp.2023.105154","article-title":"Microstructure and Mechanical Properties of Interlayer Regions in Extrusion-Based 3D Printed Concrete: A Critical Review","volume":"141","author":"Ding","year":"2023","journal-title":"Cem. Concr. Compos."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1080\/17452759.2018.1500420","article-title":"Time Gap Effect on Bond Strength of 3D-Printed Concrete","volume":"14","author":"Tay","year":"2019","journal-title":"Virtual Phys. Prototyp."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.cemconres.2019.02.017","article-title":"Hardened Properties of 3D Printed Concrete: The Influence of Process Parameters on Interlayer Adhesion","volume":"119","author":"Wolfs","year":"2019","journal-title":"Cem. Concr. Res."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"135463","DOI":"10.1016\/j.conbuildmat.2024.135463","article-title":"Interlayer Mechanical Performance of 3D-Printed Cementitious Systems: A Comprehensive Study on Operational and Material Parameters","volume":"419","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"127151","DOI":"10.1016\/j.conbuildmat.2022.127151","article-title":"Interlayer Bonding Investigation of 3D Printing Cementitious Materials with Fluidity-Retaining Polycarboxylate Superplasticizer and High-Dispersion Polycarboxylate Superplasticizer","volume":"330","author":"Pan","year":"2022","journal-title":"Constr. Build. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"120094","DOI":"10.1016\/j.conbuildmat.2020.120094","article-title":"Effect of Printing Parameters on Interlayer Bond Strength of 3D Printed Limestone-Calcined Clay-Based Cementitious Materials: An Experimental and Numerical Study","volume":"262","author":"Chen","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Hager, I., Maroszek, M., Mr\u00f3z, K., K\u0119sek, R., Hebda, M., Dvorkin, L., and Marchuk, V. (2022). Interlayer Bond Strength Testing in 3D-Printed Mineral Materials for Construction Applications. Materials, 15.","DOI":"10.3390\/ma15124112"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"130936","DOI":"10.1016\/j.conbuildmat.2023.130936","article-title":"Effects of Interval Time and Interfacial Agents on the Mechanical Characteristics of Ultra-High Toughnessnn Cementitious Composites under 3D-Printed Technology","volume":"374","author":"Luo","year":"2023","journal-title":"Constr. Build. Mater."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"104742","DOI":"10.1016\/j.cemconcomp.2022.104742","article-title":"3D Printing Concrete with Recycled Coarse Aggregates: The Influence of Pore Structure on Interlayer Adhesion","volume":"134","author":"Liu","year":"2022","journal-title":"Cem. Concr. Compos."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Panda, B., Noor Mohamed, N.A., Paul, S.C., Bhagath Singh, G., Tan, M.J., and \u0160avija, B. (2019). The Effect of Material Fresh Properties and Process Parameters on Buildability and Interlayer Adhesion of 3D Printed Concrete. Materials, 12.","DOI":"10.3390\/ma12132149"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"132424","DOI":"10.1016\/j.conbuildmat.2023.132424","article-title":"Interlayer Adhesion of 3D Printed Concrete: Influence of Layer Stacked Vertically","volume":"399","author":"Zhang","year":"2023","journal-title":"Constr. Build. Mater."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5481","DOI":"10.1002\/suco.202200473","article-title":"Mechanical Properties, Durability Performance and Interlayer Adhesion of 3DPC Mixtures: A State-of-the-art Review","volume":"24","author":"Mardani","year":"2023","journal-title":"Struct. Concr."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Babafemi, A.J., Kolawole, J.T., Miah, M.J., Paul, S.C., and Panda, B. (2021). A Concise Review on Interlayer Bond Strength in 3D Concrete Printing. Sustainability, 13.","DOI":"10.3390\/su13137137"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.autcon.2017.08.019","article-title":"Effects of Interlocking on Interlayer Adhesion and Strength of Structures in 3D Printing of Concrete","volume":"83","author":"Zareiyan","year":"2017","journal-title":"Autom. Constr."},{"key":"ref_41","unstructured":"(2016). Methods of Testing Cement\u2014Part 1: Determination of Strength (Standard No. EN 196-1:2016)."},{"key":"ref_42","unstructured":"(1999). Methods of Test for Mortar for Masonry. Determination of Consistence of Fresh Mortar (by Flow Table) (Standard No. EN 1015-3:1999)."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"132962","DOI":"10.1016\/j.conbuildmat.2023.132962","article-title":"Rheology and Pumpability of Mix Suitable for Extrusion-Based Concrete 3D Printing\u2014A Review","volume":"402","author":"Paritala","year":"2023","journal-title":"Constr. Build. Mater."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"105523","DOI":"10.1016\/j.cemconcomp.2024.105523","article-title":"Water Loss and Shrinkage Prediction in 3D Printed Concrete with Varying w\/c and Specimen Sizes","volume":"149","author":"Ma","year":"2024","journal-title":"Cem. Concr. Compos."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"107394","DOI":"10.1016\/j.jobe.2023.107394","article-title":"Research Progress on Shrinkage Properties of Extruded 3D Printed Cement-Based Materials","volume":"77","author":"Zhu","year":"2023","journal-title":"J. Build. Eng."},{"key":"ref_46","first-page":"104206","article-title":"Effect of Time Interval on the Interlayer Adhesion of 3D Printed Concrete with Recycled Sand: Multi-Factor Influencing Mechanisms and Superabsorbent Polymer Enhancement","volume":"86","author":"Wu","year":"2024","journal-title":"Addit. Manuf."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"106559","DOI":"10.1016\/j.cemconres.2021.106559","article-title":"Modelling the Interlayer Bond Strength of 3D Printed Concrete with Surface Moisture","volume":"150","author":"Moelich","year":"2021","journal-title":"Cem. Concr. Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"04023362","DOI":"10.1061\/JMCEE7.MTENG-14515","article-title":"Effect of Interlayer Time-Lapse and Workability Retention on Printed Concrete Performance","volume":"35","author":"Ghosh","year":"2023","journal-title":"J. Mater. Civ. Eng."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1007\/s41024-025-00626-4","article-title":"From Printing to Performance: A Review on 3D Concrete Printing Processes, Materials, and Life Cycle Assessment","volume":"10","author":"Mishra","year":"2025","journal-title":"J. Build. Pathol. Rehabil."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/16\/3845\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:28:44Z","timestamp":1760034524000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/16\/3845"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,15]]},"references-count":49,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2025,8]]}},"alternative-id":["ma18163845"],"URL":"https:\/\/doi.org\/10.3390\/ma18163845","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,15]]}}}