{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T02:15:07Z","timestamp":1790907307597,"version":"4.1.0"},"reference-count":54,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T00:00:00Z","timestamp":1779321600000},"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, China","doi-asserted-by":"publisher","award":["52578254"],"award-info":[{"award-number":["52578254"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["52578254"],"award-info":[{"award-number":["52578254"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Zhejiang Provincial Natural Science Foundation of China","award":["LZ26E080001"],"award-info":[{"award-number":["LZ26E080001"]}]},{"award":["LZ26E080001"],"award-info":[{"award-number":["LZ26E080001"]}],"id":[{"id":"https:\/\/ror.org\/04aqat463","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Construction Research Project of Zhejiang Province, China","award":["2024K362"],"award-info":[{"award-number":["2024K362"]}]},{"name":"Science and Technology Program Project of the Zhejiang Provincial Department of Transportation, China","award":["2025010"],"award-info":[{"award-number":["2025010"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Ultra-high-performance concrete incorporating coarse aggregates (UHPC-CA) exhibits pronounced multi-scale heterogeneity and staged damage evolution. However, existing single-scale reinforcement strategies often fail to address the complete micro-to-macro fracture process, leaving a critical research gap in achieving full-stage crack control. To address this, this study introduces a novel cross-scale toughening strategy using hybrid steel fibers (SF) and calcium carbonate whiskers (CCW), and decouples the coupled influences of water-to-binder (W\/B) ratio, coarse aggregate (CA), and multi-scale fibers via an orthogonal design. Mechanical properties, fiber dispersion, and pore structure are jointly characterized to establish structure\u2013property relationships. An optimal composition (W\/B = 0.32, CA = 18%, SF = 2%, CCW = 1%) is identified, achieving a balanced enhancement of strength and ductility. Results indicate that matrix densification is primarily controlled by W\/B via pore refinement, while mechanical performance is governed by the interplay between fiber spatial uniformity and interfacial integrity; the roles of CA and CCW are clearly stress-state dependent. Furthermore, a novel cross-scale synergistic mechanism is revealed, in which micro-scale CCW regulates microcrack initiation and stabilizes the pre-peak response, whereas macro-scale SF dominates post-peak behavior through crack bridging and pull-out energy dissipation. This sequential activation enables a full-stage enhancement of tensile performance, shifting failure from brittle localization to pseudo-ductile multiple cracking. The findings provide a correlative framework for tailoring UHPC-CA through multi-scale hybrid reinforcement.<\/jats:p>","DOI":"10.3390\/ma19102171","type":"journal-article","created":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T13:53:24Z","timestamp":1779371604000},"page":"2171","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Deconstructing Multi-Scale Hybrid Fiber-Reinforced Coarse Aggregate UHPC: From Pore Structure Tailoring to Cross-Scale Toughening"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8521-5040","authenticated-orcid":false,"given":"Jiyang","family":"Wang","sequence":"first","affiliation":[{"name":"Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yalong","family":"Wang","sequence":"additional","affiliation":[{"name":"Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lingbo","family":"Wang","sequence":"additional","affiliation":[{"name":"Zhejiang Communications Construction Group Co., Ltd., Hangzhou 310007, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Peng","sequence":"additional","affiliation":[{"name":"Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"Zhang","sequence":"additional","affiliation":[{"name":"Zhejiang Academy of Building Research & Design Co., Ltd., Hangzhou 310012, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingwen","family":"Shi","sequence":"additional","affiliation":[{"name":"Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xianmo","family":"Xu","sequence":"additional","affiliation":[{"name":"Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuyu","family":"Lin","sequence":"additional","affiliation":[{"name":"Institute of Advanced Engineering Structures, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"110374","DOI":"10.1016\/j.engstruct.2020.110374","article-title":"Ultra high performance concrete (UHPC) sleeper: Structural design and performance","volume":"210","author":"Bae","year":"2020","journal-title":"Eng. 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