{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T12:45:47Z","timestamp":1785415547279,"version":"3.56.0"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T00:00:00Z","timestamp":1777593600000},"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":["52278469"],"award-info":[{"award-number":["52278469"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["52278469"],"award-info":[{"award-number":["52278469"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004735","name":"Natural Science Foundation of Hunan Province","doi-asserted-by":"publisher","award":["2022JJ30715"],"award-info":[{"award-number":["2022JJ30715"]}],"id":[{"id":"10.13039\/501100004735","id-type":"DOI","asserted-by":"publisher"}]},{"name":"China Railway Group Limited","award":["2022-Major-04"],"award-info":[{"award-number":["2022-Major-04"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The prefabricated polyurethane-solidified track bed (PPSTB) combines the adjustability of ballasted tracks with the low maintenance requirements of slab tracks, offering a promising solution for railway sections on deformable foundations. This study investigates the interaction and mechanical behaviors of the polyurethane-solidified ballast (PSB) modules and bulk ballast under laboratory loading. A series of unconfined uniaxial tests, confined ballast box tests, and cyclic loading tests were conducted, complemented by discrete element method (DEM) simulations to analyze mesoscopic particle evolution. Under monotonic compression, the stress\u2013strain curve exhibits three distinct stages with an average elastic modulus of 19.66 MPa, where the central aggregate framework acts as the primary load-bearing structure. Confinement increases the modulus by 33.57% and yields a nearly linear stress\u2013strain relationship, attributed to a more compact and uniform contact distribution. Furthermore, under cyclic loading, the PSB shows enhanced energy dissipation and deformation resistance compared to conventional ballast. These findings provide a theoretical basis for the structural design and long-term performance assessment of the PPSTB.<\/jats:p>","DOI":"10.3390\/ma19091863","type":"journal-article","created":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T06:50:01Z","timestamp":1777618201000},"page":"1863","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Polyurethane-Solidified Ballast Under Unconfined and Confined Conditions: Laboratory Load Testing and Mesoscopic Analysis"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9554-2483","authenticated-orcid":false,"given":"Wei","family":"Chen","sequence":"first","affiliation":[{"name":"School of Civil Engineering, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuojun","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shang","family":"Luo","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yushuo","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weidong","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Central South University, Changsha 410075, China"},{"name":"MOE Key Laboratory of Engineering Structures of Heavy-Haul Railway, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qiang","family":"Yuan","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Central South University, Changsha 410075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.hspr.2023.04.001","article-title":"Mechanical Properties of Foamed Polyurethane Solidified Ballasted Track","volume":"1","author":"Xu","year":"2023","journal-title":"High-Speed Railw."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1064","DOI":"10.1080\/23248378.2023.2278504","article-title":"Response of Prefabricated-Polyurethane Reinforced Ballasted Track to Dislocation in Tunnels through Active Fault Zone","volume":"12","author":"Chen","year":"2024","journal-title":"Int. J. Rail Transp."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1016\/j.conbuildmat.2013.03.002","article-title":"Reducing Railway Track Settlement Using Three-Dimensional Polyurethane Polymer Reinforcement of the Ballast","volume":"44","author":"Kennedy","year":"2013","journal-title":"Constr. Build. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1680\/geot.2008.T.005","article-title":"Influence of Particle Breakage on the Resilient Modulus of Railway Ballast","volume":"59","author":"Indraratna","year":"2009","journal-title":"G\u00e9otechnique"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1631\/jzus.A2200019","article-title":"Analysis of the Breakage Parameters of Railway Ballast Based on the Discrete Element Method","volume":"24","author":"Liu","year":"2023","journal-title":"J. Zhejiang Univ. Sci. A"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"836","DOI":"10.1631\/jzus.A12ISGT3","article-title":"Application of Polyurethane Geocomposites to Help Maintain Track Geometry for High-Speed Ballasted Railway Tracks","volume":"13","author":"Woodward","year":"2012","journal-title":"J. Zhejiang Univ. Sci. A"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"126260","DOI":"10.1016\/j.conbuildmat.2021.126260","article-title":"Mechanical Behaviour and Energy Evolution of Polyurethane-Mixed Ballast under Revised Bonding Constitutive Model","volume":"320","author":"Xiao","year":"2022","journal-title":"Constr. Build. Mater."},{"key":"ref_8","first-page":"101","article-title":"Test and Analysis of Dynamic Characteristics of Polyurethane Curing Track Bed for Jinan-Qingdao High Speed Railway","volume":"59","author":"Yang","year":"2019","journal-title":"Railw. Eng."},{"key":"ref_9","first-page":"58","article-title":"Optimal Design Scheme of Prefabricated Polyurethane Curing Track Bed","volume":"66","author":"Wang","year":"2022","journal-title":"Railw. Stand. Des."},{"key":"ref_10","first-page":"16","article-title":"Application of Polyurethane Solidified Ballast Bed Technology in Datong-Xi\u2019an HSR","volume":"6","author":"Feng","year":"2021","journal-title":"Chin. Railw."},{"key":"ref_11","first-page":"826362","article-title":"Application of Polyurethane Polymer and Assistant Rails to Settling the Abnormal Vehicle-Track Dynamic Effects in Transition Zone between Ballastless and Ballasted Track","volume":"2015","author":"Zhao","year":"2015","journal-title":"Shock Vib."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1177\/0954409711420521","article-title":"Maintaining Absolute Clearances in Ballasted Railway Tracks Using in Situ Three-Dimensional Polyurethane GeoComposites","volume":"226","author":"Woodward","year":"2012","journal-title":"Proc. Inst. Mech. Eng. Part F J. Rail Rapid Transit"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1177\/0954409720975572","article-title":"Analysis on the Track Quality Evolution Law of Polyurethane-Reinforced Ballasted Track in High-Speed Railway","volume":"235","author":"Xiao","year":"2021","journal-title":"Proc. Inst. Mech. Eng. Part F J. Rail Rapid Transit"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1080\/23248378.2019.1570477","article-title":"Polyurethane-Based Stabilization of Railroad Ballast\u2014A Critical Review","volume":"7","author":"Gundavaram","year":"2019","journal-title":"Int. J. Rail Transp."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.trgeo.2014.06.005","article-title":"Study of Railway Track Stiffness Modification by Polyurethane Reinforcement of the Ballast","volume":"1","author":"Woodward","year":"2014","journal-title":"Transp. Geotech."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"734","DOI":"10.1016\/j.conbuildmat.2019.03.031","article-title":"Polyurethane Reinforced Ballasted Track: Review, Innovation and Challenge","volume":"208","author":"Jing","year":"2019","journal-title":"Constr. Build. Mater."},{"key":"ref_17","first-page":"18","article-title":"Prefabricated polyurethane track bed structure","volume":"41","author":"Xu","year":"2020","journal-title":"Chin. Railw. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"109526","DOI":"10.1016\/j.soildyn.2025.109526","article-title":"Macroscopic and Mesoscopic Dynamic Performance of Prefabricated Polyurethane Cured Ballasted Track-Vehicle Coupling System under Cross-Fault Seismic Loading","volume":"197","author":"Ma","year":"2025","journal-title":"Soil. Dyn. Earthq. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"101736","DOI":"10.1016\/j.trgeo.2025.101736","article-title":"Discrete Element Method Analysis on Mechanical Characteristics and Response of Prefabricated Polyurethane Solidified Ballasted Bed","volume":"56","author":"Chen","year":"2026","journal-title":"Transp. Geotech."},{"key":"ref_20","unstructured":"Keene, A., Tinjum, J.M., and Edil, T.B. (2014). Mechanical Properties of Polyurethane-Stabilized Ballast. Geotech. Eng. J. SEAGS AGSSEA, 45."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.conbuildmat.2017.03.107","article-title":"An Experimental Study on the Characteristics of Polyurethane-Mixed Coarse Aggregates by Large-Scale Triaxial Test","volume":"145","author":"Lee","year":"2017","journal-title":"Constr. Build. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"119304","DOI":"10.1016\/j.conbuildmat.2020.119304","article-title":"Performance Evaluation of Polyurethane-Stabilized Railroad Ballast under Direct Shear Conditions","volume":"255","author":"Gundavaram","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"100958","DOI":"10.1016\/j.trgeo.2023.100958","article-title":"A Novel Laboratory Investigation to Characterize the Mechanical Behaviors of Polyurethane-Ballast Bonds under Complex Stress States","volume":"40","author":"Zhang","year":"2023","journal-title":"Transp. Geotech."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"04024302","DOI":"10.1061\/JMCEE7.MTENG-16292","article-title":"Effect of Polyurethane Content on the Performance of Ballasts under Static and Cyclic Loading","volume":"36","author":"Prasad","year":"2024","journal-title":"J. Mater. Civ. Eng."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Huang, Z., Su, Q., Liu, T., Huang, J., Wang, X., and Kaewunruen, S. (2024). Full-Scale Experimental and Field Investigations into Expansion Mechanism of Foamed Polyurethane and Its Lifting Behaviors for Repair and Maintenance of Railway Slab Track Systems. Polymers, 16.","DOI":"10.3390\/polym16030404"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1007\/s13349-021-00489-6","article-title":"Field Dynamic Performance Testing and Analysis of Polyurethane Track and Ballasted Track in a High-Speed Railway","volume":"11","author":"Xiong","year":"2021","journal-title":"J. Civ. Struct. Health Monit."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"100886","DOI":"10.1016\/j.trgeo.2022.100886","article-title":"Effect of Treatment Zone on the Performance of Polyurethane-Stabilized Ballast under Cyclic Loading","volume":"37","author":"Gundavaram","year":"2022","journal-title":"Transp. Geotech."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"04024209","DOI":"10.1061\/IJGNAI.GMENG-9642","article-title":"Discrete-Element Analysis for Compaction-Induced Stiffness Variation of Ballast Aggregate in Large-Scale Triaxial Testing","volume":"24","author":"Huang","year":"2024","journal-title":"Int. J. Geomech."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1177\/0954409720907420","article-title":"Investigating the Effect of Different Bonding Areas on the Lateral Resistance of Polyurethane-Mixed Ballast Using the Discrete Element Method","volume":"235","author":"Ling","year":"2021","journal-title":"Proc. Inst. Mech. Eng. Part F J. Rail Rapid Transit"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"119370","DOI":"10.1016\/j.conbuildmat.2020.119370","article-title":"Discrete Element Modeling of Polyurethane-Stabilized Ballast under Monotonic and Cyclic Triaxial Loading","volume":"255","author":"Ling","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.conbuildmat.2018.06.008","article-title":"Analysis of Mechanical Properties of Polyurethane-Mixed Ballast Based on Energy Method","volume":"182","author":"Ling","year":"2018","journal-title":"Constr. Build. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"139464","DOI":"10.1016\/j.conbuildmat.2024.139464","article-title":"Grading Analysis of Resilient Polyurethane Solidified Ballasted Bed Using the Discrete Element Method","volume":"457","author":"Xu","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"137434","DOI":"10.1016\/j.conbuildmat.2024.137434","article-title":"Experimental Investigation and Soft Bond Modelling Analysis on Mechanical Behaviours of Foamed Polyurethane Solidified Ballast","volume":"440","author":"Zhang","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"107093","DOI":"10.1016\/j.soildyn.2021.107093","article-title":"Static and Cyclic Compressive Mechanical Characterization of Polyurethane-Reinforced Ballast in a Railway","volume":"153","author":"Liu","year":"2022","journal-title":"Soil. Dyn. Earthq. Eng."},{"key":"ref_35","first-page":"1113","article-title":"Compression performance of polyurethane reinforced ballast bed ballast body under uniaxial load","volume":"18","author":"Yu","year":"2021","journal-title":"J. Railw. Sci. Eng."},{"key":"ref_36","first-page":"230","article-title":"Experimental study on influences of scale effect on mechanical properties of railway ballast","volume":"40","author":"Yao","year":"2018","journal-title":"Chin. J. Geotech. Eng."},{"key":"ref_37","first-page":"1","article-title":"Preparation of Polyurethane Composite Material and Assembled Polyurethane Curing Ballast Bed","volume":"63","author":"Zhang","year":"2023","journal-title":"Railw. Eng."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1061\/(ASCE)GM.1943-5622.0000264","article-title":"Behavior of Fresh and Fouled Railway Ballast Subjected to Direct Shear Testing: Discrete Element Simulation","volume":"14","author":"Indraratna","year":"2014","journal-title":"Int. J. Geomech."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1371","DOI":"10.1007\/s11595-019-2201-0","article-title":"Effect of Cellular Structure on Mechanical Properties of Polyurethane Foam Curing Materials","volume":"34","author":"Zheng","year":"2019","journal-title":"J. Wuhan Univ. Technol.-Mater. Sci. Ed."},{"key":"ref_40","first-page":"90","article-title":"Study on Reasonable Design Parameters of Prefab Polyurethane Railway Track Bed","volume":"59","author":"Xu","year":"2019","journal-title":"Railw. Eng."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/9\/1863\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T06:52:24Z","timestamp":1777618344000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/9\/1863"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,1]]},"references-count":40,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["ma19091863"],"URL":"https:\/\/doi.org\/10.3390\/ma19091863","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,1]]}}}