{"title":"水热合成-低温煅烧法制备新型煤矸石基胶凝材料","authors":"Tingye Qi, Lubin Li, Junjie He, Guorui Feng, Linfei Wang, Hongtao Xu, Tian Qiu, Siyuan Cheng, Xinkai Qi, Kexin Xu","doi":"10.1617/s11527-025-02769-9","DOIUrl":null,"url":null,"abstract":"<div><p>Traditional cement-based materials’ economic and environmental concerns urge low-carbon alternatives. This study activates coal gangue via hydrothermal synthesis − low temperature calcination to explore optimal activation conditions for cement substitution. A Box-Behnken response surface experiment was designed with 28d compressive strength as the response index to study the effects of hydrothermal temperature, Ca/Si ratio, NaOH concentration, and calcination temperature on coal gangue-based cementitious materials. Single-factor optimization was conducted based on significant factors identified via response surface analysis. Phase evolution and hydration mechanisms were analyzed using XRD, SEM, TG-DSC, etc. Results indicated that optimal conditions were 90 °C, Ca/Si = 2.0, NaOH = 1.5%, and 800 °C, with the Ca/Si ratio and calcination temperature exerting the most significant impact, achieving a 28d compressive strength of 20.1 MPa. At Ca/Si = 2.0, the highest content of C<sub>12</sub>A<sub>7</sub> was found in the clinker. The formation of β-C<sub>2</sub>S and α’<sub>H</sub>-C<sub>2</sub>S at 800 °C facilitated the densification of C–S–H with ettringite. Hydrothermal pre-treatment lowered the C<sub>2</sub>S synthesis temperature by 200 °C and enhanced the 28d compressive strength to 191% of that obtained using the one-step calcination method. The results provide theoretical support for the utilization of coal gangue as a cementitious material, promoting its sustainable resource utilization.</p></div>","PeriodicalId":691,"journal":{"name":"Materials and Structures","volume":"58 7","pages":""},"PeriodicalIF":3.9000,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Preparation of new coal gangue-based cementitious material via hydrothermal synthesis–low temperature calcination method\",\"authors\":\"Tingye Qi, Lubin Li, Junjie He, Guorui Feng, Linfei Wang, Hongtao Xu, Tian Qiu, Siyuan Cheng, Xinkai Qi, Kexin Xu\",\"doi\":\"10.1617/s11527-025-02769-9\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Traditional cement-based materials’ economic and environmental concerns urge low-carbon alternatives. This study activates coal gangue via hydrothermal synthesis − low temperature calcination to explore optimal activation conditions for cement substitution. A Box-Behnken response surface experiment was designed with 28d compressive strength as the response index to study the effects of hydrothermal temperature, Ca/Si ratio, NaOH concentration, and calcination temperature on coal gangue-based cementitious materials. Single-factor optimization was conducted based on significant factors identified via response surface analysis. Phase evolution and hydration mechanisms were analyzed using XRD, SEM, TG-DSC, etc. Results indicated that optimal conditions were 90 °C, Ca/Si = 2.0, NaOH = 1.5%, and 800 °C, with the Ca/Si ratio and calcination temperature exerting the most significant impact, achieving a 28d compressive strength of 20.1 MPa. At Ca/Si = 2.0, the highest content of C<sub>12</sub>A<sub>7</sub> was found in the clinker. The formation of β-C<sub>2</sub>S and α’<sub>H</sub>-C<sub>2</sub>S at 800 °C facilitated the densification of C–S–H with ettringite. Hydrothermal pre-treatment lowered the C<sub>2</sub>S synthesis temperature by 200 °C and enhanced the 28d compressive strength to 191% of that obtained using the one-step calcination method. The results provide theoretical support for the utilization of coal gangue as a cementitious material, promoting its sustainable resource utilization.</p></div>\",\"PeriodicalId\":691,\"journal\":{\"name\":\"Materials and Structures\",\"volume\":\"58 7\",\"pages\":\"\"},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2025-08-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials and Structures\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://link.springer.com/article/10.1617/s11527-025-02769-9\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CONSTRUCTION & BUILDING TECHNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials and Structures","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1617/s11527-025-02769-9","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
Preparation of new coal gangue-based cementitious material via hydrothermal synthesis–low temperature calcination method
Traditional cement-based materials’ economic and environmental concerns urge low-carbon alternatives. This study activates coal gangue via hydrothermal synthesis − low temperature calcination to explore optimal activation conditions for cement substitution. A Box-Behnken response surface experiment was designed with 28d compressive strength as the response index to study the effects of hydrothermal temperature, Ca/Si ratio, NaOH concentration, and calcination temperature on coal gangue-based cementitious materials. Single-factor optimization was conducted based on significant factors identified via response surface analysis. Phase evolution and hydration mechanisms were analyzed using XRD, SEM, TG-DSC, etc. Results indicated that optimal conditions were 90 °C, Ca/Si = 2.0, NaOH = 1.5%, and 800 °C, with the Ca/Si ratio and calcination temperature exerting the most significant impact, achieving a 28d compressive strength of 20.1 MPa. At Ca/Si = 2.0, the highest content of C12A7 was found in the clinker. The formation of β-C2S and α’H-C2S at 800 °C facilitated the densification of C–S–H with ettringite. Hydrothermal pre-treatment lowered the C2S synthesis temperature by 200 °C and enhanced the 28d compressive strength to 191% of that obtained using the one-step calcination method. The results provide theoretical support for the utilization of coal gangue as a cementitious material, promoting its sustainable resource utilization.
期刊介绍:
Materials and Structures, the flagship publication of the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM), provides a unique international and interdisciplinary forum for new research findings on the performance of construction materials. A leader in cutting-edge research, the journal is dedicated to the publication of high quality papers examining the fundamental properties of building materials, their characterization and processing techniques, modeling, standardization of test methods, and the application of research results in building and civil engineering. Materials and Structures also publishes comprehensive reports prepared by the RILEM’s technical committees.