{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T16:14:37Z","timestamp":1785428077712,"version":"3.56.0"},"reference-count":44,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T00:00:00Z","timestamp":1778803200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52479103"],"award-info":[{"award-number":["52479103"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["52479103"],"award-info":[{"award-number":["52479103"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Innovation Group Project of Hubei Natural Science Foundation","award":["2025AFA015"],"award-info":[{"award-number":["2025AFA015"]}]},{"name":"Research and Innovation Fund of the College of Civil Engineering & Architecture, Three Gorges University, China","award":["2024BSCX004"],"award-info":[{"award-number":["2024BSCX004"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Understanding the anisotropy in the physical and mechanical properties of layered rocks is essential for predicting and preventing instability in layered rock masses. However, in-situ sampling is often hindered by the difficulty of obtaining specimens with controlled bedding orientations. Cement-based 3D printing (3DP) offers an efficient approach for fabricating rock analogues, yet the inherent anisotropy induced by the layer-by-layer deposition process has not been well characterized, hindering its broader application. The objectives of this study are (i) to systematically evaluate the intrinsic anisotropy of cement-based 3DP rocks and (ii) to compare the mechanical anisotropy and failure modes of 3DP layered rocks with those of natural layered sandstone. The key findings are as follows: (1) The uniaxial compressive strength (UCS), P-wave velocity, and computed tomography (CT) number of the 3DP rock vary by less than 6% among the X-, Y-, and Z-directions, indicating lower intrinsic anisotropy compared to typical sandstones and several other natural rocks. (2) The UCS, elastic modulus, and secant modulus of the 3DP layered rocks all decrease initially and then increase with bedding dip angle, reaching a minimum at 60\u00b0. (3) The main fracture characteristics of the 3DP layered rocks are similar to those of layered sandstone; notably, the 3DP layered soft rock exhibits the most pronounced shear failure features. This study quantifies the low intrinsic anisotropy of cement-based 3DP rocks and validates their similarity to natural layered sandstone in both mechanical anisotropy and failure modes. It thereby provides a reliable, reproducible basis for physical modeling of layered rock masses using 3DP, offering a new approach for laboratory-scale investigations of layered rocks.<\/jats:p>","DOI":"10.3390\/ma19102067","type":"journal-article","created":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T10:33:21Z","timestamp":1778841201000},"page":"2067","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Development of 3D-Printed Cementitious Layered Model Rocks with Recycled Waste: A Study on Anisotropy"],"prefix":"10.3390","volume":"19","author":[{"given":"Yongbo","family":"Hu","sequence":"first","affiliation":[{"name":"Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, 8 Daxue Road, Yichang 443002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yugao","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, 8 Daxue Road, Yichang 443002, China"},{"name":"Jilin Polytechnic of Water Resources and Electric Engineering, 6566 Juye Street, Changchun 130117, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhenxing","family":"Wang","sequence":"additional","affiliation":[{"name":"China Three Gorges Corporation, 1 Liuhe Road, Wuhan 430010, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuying","family":"Wang","sequence":"additional","affiliation":[{"name":"Xiantao Anjie Highway Maintenance Co., Ltd., 3 Hanjiang Road, Xiantao 433000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinsong","family":"Hu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, 8 Daxue Road, Yichang 443002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lehua","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, 8 Daxue Road, Yichang 443002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoliang","family":"Xu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, 8 Daxue Road, Yichang 443002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.ijrmms.2008.04.001","article-title":"Modeling mechanical layering effects on stability of underground openings in jointed sedimentary rocks","volume":"46","author":"Hatzor","year":"2009","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3381","DOI":"10.1007\/s11440-021-01268-9","article-title":"Impacts of saturation-dependent anisotropy on the shrinkage behavior of clay rocks","volume":"16","author":"Ip","year":"2021","journal-title":"Acta Geotech."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"137360","DOI":"10.1016\/j.energy.2025.137360","article-title":"Feasibility and stability study of single-well retreating horizontal cavern gas storage in deep bedded salt rock of Liulin, China","volume":"2025","author":"Zhang","year":"2025","journal-title":"Energy"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1007\/s10035-023-01311-4","article-title":"Tensile behavior of layered rock disks under diametral loading: Experimental and numerical investigations","volume":"25","author":"Asadizadeh","year":"2023","journal-title":"Granul. Matter"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"104621","DOI":"10.1016\/j.ijrmms.2021.104621","article-title":"Crack coalescence in rock-like specimens with two dissimilar layers and pre-existing double parallel joints under uniaxial compression","volume":"139","author":"Lin","year":"2021","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_6","first-page":"107128","article-title":"Analysis of rheological properties and printability of a 3D-printing mortar containing silica fume, hydrated lime, and blast furnace slag, Mater","volume":"37","author":"Bayat","year":"2023","journal-title":"Today Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"104350","DOI":"10.1016\/j.cemconcomp.2021.104350","article-title":"Influence of substrate surface roughness and moisture content on tensile adhesion performance of 3D printable concrete","volume":"126","author":"Tao","year":"2022","journal-title":"Cem. Concr. Compos."},{"key":"ref_8","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_9","doi-asserted-by":"crossref","first-page":"5735","DOI":"10.1007\/s11440-023-01981-7","article-title":"3D printed porous particle and its geotechnical properties","volume":"18","author":"Matsumura","year":"2023","journal-title":"Acta Geotech."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"103192","DOI":"10.1016\/j.jngse.2020.103192","article-title":"Experimental investigation of 3D printed rock samples replicas","volume":"76","author":"Almetwally","year":"2020","journal-title":"J. Nat. Gas Sci. Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"10258","DOI":"10.1016\/j.ceramint.2018.03.031","article-title":"Experimental study on mix proportion and fresh properties of fly ash based geopolymer for 3D concrete printing","volume":"44","author":"Panda","year":"2018","journal-title":"Ceram. Int."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"105653","DOI":"10.1016\/j.cemconcomp.2024.105653","article-title":"3D printing with stabilized earth: Material development and effect of carbon sequestration on engineering performance","volume":"152","author":"Sahana","year":"2024","journal-title":"Cem. Concr. Compos."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Sanchez-Barra, A., Zambrano-Narvaez, G., and Chalaturnyk, R. (2023). An In-Depth Analysis of Strength and Stiffness Variability in 3D-Printed Sandstones: Implications for Geomechanics. Energies, 16.","DOI":"10.20944\/preprints202306.1832.v1"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2261","DOI":"10.1007\/s00603-018-1703-y","article-title":"The 3D-printing technology of geological models using rock-like materials","volume":"52","author":"Feng","year":"2019","journal-title":"Rock Mech. Rock Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1007\/s00603-019-01926-1","article-title":"A new way to replicate the highly stressed soft rock: 3D printing exploration","volume":"53","author":"Wu","year":"2020","journal-title":"Rock Mech. Rock Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"7695","DOI":"10.1007\/s00603-022-03054-9","article-title":"A Novel 3D Printing Technology for Synthetic Hard Rock and the Fabrication of Jinping Marble","volume":"55","author":"Mei","year":"2022","journal-title":"Rock Mech. Rock Eng."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"04023139","DOI":"10.1061\/IJGNAI.GMENG-8510","article-title":"Experimental study on the failure process of fault rock bursts in tunnels based on a 3D-printed large-scale physical model","volume":"23","author":"Mei","year":"2023","journal-title":"Int. J. Geomech."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"105173","DOI":"10.1016\/j.ijrmms.2022.105173","article-title":"Mechanical performance of a 3D printed scaled mine roadway model","volume":"158","author":"Feng","year":"2022","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"105135","DOI":"10.1016\/j.tust.2023.105135","article-title":"Size effects in cavern model tests based on 3D printing","volume":"137","author":"Wang","year":"2023","journal-title":"Tunn. Undergr. Space Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"7005","DOI":"10.1007\/s00603-022-03013-4","article-title":"Size effect of fractured rock mass based on 3d printed model testing","volume":"55","author":"Wang","year":"2022","journal-title":"Rock Mech. Rock Eng."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1007\/s10035-021-01143-0","article-title":"Triaxial compression behavior of 3D printed and natural sands","volume":"23","author":"Ahmed","year":"2021","journal-title":"Granul. Matter"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1007\/s11242-018-1153-8","article-title":"Compressive and tensile behavior of 3D-printed and natural sandstones","volume":"129","author":"Perras","year":"2019","journal-title":"Transp. Porous Media"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"108827","DOI":"10.1016\/j.petrol.2021.108827","article-title":"Characterization and microfabrication of natural porous rocks: From micro-CT imaging and digital rock modelling to micro-3D-printed rock analogs","volume":"205","author":"Song","year":"2021","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Van, D., Deprez, M., Cnudde, V., De, S., and Van, T. (2019). Microstructural characterization of 3D printed cementitious materials. Materials, 12.","DOI":"10.3390\/ma12182993"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Xu, Q., Jiang, L., Ma, C., Niu, Q., and Wang, X. (2021). Effect of layer thickness on the physical and mechanical properties of sand powder 3D printing specimens. Front. Earth Sci., 9.","DOI":"10.3389\/feart.2021.763202"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"685","DOI":"10.1016\/j.cherd.2022.08.046","article-title":"Experimental investigation of the flow properties of layered coal-rock analogues","volume":"186","author":"Santiago","year":"2022","journal-title":"Chem. Eng. Res. Des."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"8793214","DOI":"10.1155\/2020\/8793214","article-title":"Investigation of the Anisotropic Characteristics of Layered Rocks under Uniaxial Compression Based on the 3D Printing Technology and the Combined Finite-Discrete Element Method","volume":"2020","author":"He","year":"2020","journal-title":"Adv. Mater. Sci. Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"6503","DOI":"10.1007\/s00603-023-03401-4","article-title":"A comprehensive experimental study on mechanical anisotropy and failure mode of 3D printed gypsum rocks: From composition and microstructure to macroscopic mechanical properties response","volume":"56","author":"Shao","year":"2023","journal-title":"Rock Mech. Rock Eng."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1034","DOI":"10.1093\/gji\/ggu181","article-title":"Strength and failure characteristics of Jurassic Red-Bed sandstone under cyclic wetting\u2013drying conditions","volume":"198","author":"Zhang","year":"2014","journal-title":"Geophys. J. Int."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1607","DOI":"10.1007\/s10064-017-1107-3","article-title":"Strength deterioration of a Shaly sandstone under dry\u2013wet cycles: A case study from the Three Gorges Reservoir in China","volume":"77","author":"Liu","year":"2018","journal-title":"Bull. Eng. Geol. Environ."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Xu, Z., Feng, G., Sun, Q., Zhang, G., and He, Y. (2020). A modified model for predicting the strength of drying-wetting cycled sandstone based on the P-wave velocity. Sustainability, 12.","DOI":"10.3390\/su12145655"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"715","DOI":"10.1007\/s12205-016-3645-9","article-title":"Experimental study on time-dependent behavior of silty mudstone from the Three Gorges Reservoir Area, China","volume":"21","author":"Yu","year":"2017","journal-title":"KSCE J. Civ. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"106159","DOI":"10.1016\/j.enggeo.2021.106159","article-title":"Creep behaviour of saturated purple mudstone under triaxial compression","volume":"288","author":"Wang","year":"2021","journal-title":"Eng. Geol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"107013","DOI":"10.1016\/j.enggeo.2023.107013","article-title":"Experimental study of the influence of wetting and drying cycles on the strength of intact rock samples from a red stratum in the Three Gorges Reservoir area","volume":"314","author":"Wu","year":"2023","journal-title":"Eng. Geol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"110864","DOI":"10.1016\/j.mtcomm.2024.110864","article-title":"Effect of alkali metal sulfates on hydration properties of alpha-calcium sulfate hemihydrate for 3D printing","volume":"41","author":"Zhi","year":"2024","journal-title":"Mater. Today Commun."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1922","DOI":"10.1016\/j.jmrt.2023.03.145","article-title":"Experimental investigation on mechanical properties and deformation mechanism of soft-hard interbedded rock-like material based on digital image correlation","volume":"24","author":"Luo","year":"2023","journal-title":"J. Mater. Res. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"113965","DOI":"10.1016\/j.jobe.2025.113965","article-title":"Mechanical Properties and Anisotropy of 3D-Printed Concrete Modified with Multiscale Materials Based on Optimized Printing Process Design","volume":"2025","author":"Li","year":"2025","journal-title":"J. Build. Eng."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"106467","DOI":"10.1016\/j.ijrmms.2026.106467","article-title":"Measurement of 3-dimensional anisotropy of P-wave velocity and elastic modulus using cylindrical cores","volume":"201","author":"Kim","year":"2026","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_39","first-page":"112","article-title":"Experimental study on anisotropic characteristics of bedded sandstone","volume":"37","author":"Deng","year":"2018","journal-title":"Chin. J. Rock Mech. Eng."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.enggeo.2008.06.011","article-title":"Analysis of small-scale heterogeneity in clastic rocks by using computerized X-ray tomography (CT)","volume":"103","author":"Geiger","year":"2009","journal-title":"Eng. Geol."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Song, Z., Zhang, J., and Wu, S. (2023). Mohr\u2013Coulomb and Modified Hoek\u2013Brown Strength Criteria of Layered Sandstone Considering the Unloading Effect and Anisotropy. Sustainability, 15.","DOI":"10.3390\/su151914418"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/S1365-1609(97)80029-9","article-title":"Laboratory investigation of the mechanical behaviour of Tournemire shale","volume":"34","author":"Niandou","year":"1997","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.ijrmms.2017.06.006","article-title":"An enhanced equivalent continuum model for layered rock mass incorporating bedding structure and stress dependence","volume":"97","author":"Zhou","year":"2017","journal-title":"Int. J. Rock Mech. Min. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"138687","DOI":"10.1016\/j.conbuildmat.2024.138687","article-title":"3D printable cement-based composites reinforced with Sisal fibers: Rheology, printability and hardened properties","volume":"450","author":"Varela","year":"2024","journal-title":"Constr. Build. Mater."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/10\/2067\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T10:38:55Z","timestamp":1778841535000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/10\/2067"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,15]]},"references-count":44,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["ma19102067"],"URL":"https:\/\/doi.org\/10.3390\/ma19102067","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,15]]}}}