{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T08:52:26Z","timestamp":1780044746408,"version":"3.53.1"},"reference-count":30,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,11,17]],"date-time":"2025-11-17T00:00:00Z","timestamp":1763337600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Xinjiang Autonomous Region Major Science and Technology Project","award":["2024A03001-2"],"award-info":[{"award-number":["2024A03001-2"]}]},{"name":"Shandong Provincial Natural Science Foundation, Youth Program","award":["ZR2025MS946"],"award-info":[{"award-number":["ZR2025MS946"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>This study systematically investigates the mechanical behavior and failure mechanisms of cemented tailings backfill (CTB) prepared from classified and unclassified tailings across cement-to-tailings (C\/T) ratios of 1:8, 1:6, and 1:4 and slurry concentrations of 60%, 65%, and 70%. Specimens were evaluated by uniaxial compression (UCS) tests, failure mode observation, and SEM. The results show that increasing C\/T and concentration markedly enhances compressive strength: the maximum 28-day UCS reached 5.38 MPa under unclassified tailings, C\/T = 1:4, 70%. Moreover, unclassified tailings exhibited a later-age strength gain of 244.9%, far exceeding the 58.5% observed for classified tailings. Failure modes evolve from brittle splitting to shear-dominated behavior as mixes densify, reflecting a transition from near-symmetric early-age stress\/microstructural fields to asymmetric localized failure (symmetry breaking). SEM reveals that higher binder ratios and concentrations promote C-(A)-S-H-dominated gel formation, improved ITZ continuity, and reduced apparent porosity, thereby restraining microcrack initiation and coalescence. These findings elucidate the micro-to-macro mechanisms governing CTB strength and failure and provide field-relevant guidance for mix optimization and safe, efficient underground backfilling.<\/jats:p>","DOI":"10.3390\/sym17111986","type":"journal-article","created":{"date-parts":[[2025,11,17]],"date-time":"2025-11-17T14:04:07Z","timestamp":1763388247000},"page":"1986","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Multi-Scale Investigation on Strength, Fracture Behavior, and Microstructure of Cemented Tailings Backfill Under Varying Mix Proportions"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-2798-3077","authenticated-orcid":false,"given":"Wenhai","family":"Liang","sequence":"first","affiliation":[{"name":"Backfill Engineering Laboratory, Shandong Gold Mining Technology Co., Ltd., Yantai 261400, China"},{"name":"Shandong Provincial Key Laboratory of Smart-Green Exploitation for Deep-Earth Coastal Gold Deposits, Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9459-2021","authenticated-orcid":false,"given":"Haosen","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Geology and Mining Engineering, Xinjiang University, Urumqi 830047, China"},{"name":"Collaborative Innovation Center of Green Mining and Ecological Restoration for Xinjiang Mineral Resources, Urumqi 830047, China"},{"name":"Xinjiang Green Blasting Engineering Technology Research Center, Changji 831100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinsheng","family":"Xin","sequence":"additional","affiliation":[{"name":"Shandong Gold Group Co., Ltd., Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-7037-4495","authenticated-orcid":false,"given":"Liu","family":"Yang","sequence":"additional","affiliation":[{"name":"Backfill Engineering Laboratory, Shandong Gold Mining Technology Co., Ltd., Yantai 261400, China"},{"name":"Shandong Provincial Key Laboratory of Smart-Green Exploitation for Deep-Earth Coastal Gold Deposits, Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yunpeng","family":"Kou","sequence":"additional","affiliation":[{"name":"Backfill Engineering Laboratory, Shandong Gold Mining Technology Co., Ltd., Yantai 261400, China"},{"name":"Shandong Provincial Key Laboratory of Smart-Green Exploitation for Deep-Earth Coastal Gold Deposits, Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zaihai","family":"Wu","sequence":"additional","affiliation":[{"name":"Backfill Engineering Laboratory, Shandong Gold Mining Technology Co., Ltd., Yantai 261400, China"},{"name":"Shandong Provincial Key Laboratory of Smart-Green Exploitation for Deep-Earth Coastal Gold Deposits, Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Baoshan","family":"Zhan","sequence":"additional","affiliation":[{"name":"Backfill Engineering Laboratory, Shandong Gold Mining Technology Co., Ltd., Yantai 261400, China"},{"name":"Shandong Provincial Key Laboratory of Smart-Green Exploitation for Deep-Earth Coastal Gold Deposits, Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,17]]},"reference":[{"key":"ref_1","first-page":"2724","article-title":"Optimization of mixture ratio and microstructure influence mechanism of composite filling slurry based on response surface method","volume":"38","author":"Liu","year":"2021","journal-title":"Acta Mater. 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