Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate
Coal gangue, a byproduct of coal beneficiation, has low strength and high carbon content, which negatively affects the mechanical properties of concrete when used as a substrate for natural gravel. However, high temperature calcination can activate its pozzolanic properties, improving its suitabilit...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-07-01
|
| Series: | Case Studies in Construction Materials |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214509525004784 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849712356782768128 |
|---|---|
| author | Shengpeng Hao Wenyu Xu Bambesiwe M. May Zhenyu Zhang Yuyu Zhang |
| author_facet | Shengpeng Hao Wenyu Xu Bambesiwe M. May Zhenyu Zhang Yuyu Zhang |
| author_sort | Shengpeng Hao |
| collection | DOAJ |
| description | Coal gangue, a byproduct of coal beneficiation, has low strength and high carbon content, which negatively affects the mechanical properties of concrete when used as a substrate for natural gravel. However, high temperature calcination can activate its pozzolanic properties, improving its suitability for concrete production. This study investigates the microstructural and mechanical property of concrete incorporated with calcined coal gangue coarse aggregate at different temperatures (500°C, 600°C, 700°C, and 800°C). The experimental results indicate that metakaolin in coal gangue begins to decompose at 500°C, increasing the content of reactive SiO2 and Al2O3, which participate in secondary hydration reactions with calcium hydroxide (CH). This process forms additional calcium silicate hydrate (C-S-H) gel, ettringite (AFT) crystals, and afwillite, enhancing the concrete microstructure. Notably, coal gangue concrete calcined at 800°C exhibited a porosity of 1.29 % and a compressive strength of 38 MPa after 28 days of curing, meeting the C30 concrete standard. Furthermore, the correlation between the compressive strength of CCGC and its microstructure exceeded 0.72, indicating that fractal dimension analysis is an effective method for predicting concrete strength. |
| format | Article |
| id | doaj-art-de4ad250849c4e34b1a0de578a4b16f3 |
| institution | DOAJ |
| issn | 2214-5095 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Construction Materials |
| spelling | doaj-art-de4ad250849c4e34b1a0de578a4b16f32025-08-20T03:14:17ZengElsevierCase Studies in Construction Materials2214-50952025-07-0122e0468010.1016/j.cscm.2025.e04680Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregateShengpeng Hao0Wenyu Xu1Bambesiwe M. May2Zhenyu Zhang3Yuyu Zhang4State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Geofluids, Geomechanics and Geoenergy (3G) Research Group, Chongqing University, Chongqing 400044, China; Corresponding author at: State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Geofluids, Geomechanics and Geoenergy (3G) Research Group, Chongqing University, Chongqing 400044, ChinaAfrican Rainbow Minerals Geometallurgy Chair, Department of Earth Sciences, Stellenbosch University, Stellenbosch 7600, South AfricaState Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Geofluids, Geomechanics and Geoenergy (3G) Research Group, Chongqing University, Chongqing 400044, ChinaDepartment of Civil, Geological and Mining Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, CanadaCoal gangue, a byproduct of coal beneficiation, has low strength and high carbon content, which negatively affects the mechanical properties of concrete when used as a substrate for natural gravel. However, high temperature calcination can activate its pozzolanic properties, improving its suitability for concrete production. This study investigates the microstructural and mechanical property of concrete incorporated with calcined coal gangue coarse aggregate at different temperatures (500°C, 600°C, 700°C, and 800°C). The experimental results indicate that metakaolin in coal gangue begins to decompose at 500°C, increasing the content of reactive SiO2 and Al2O3, which participate in secondary hydration reactions with calcium hydroxide (CH). This process forms additional calcium silicate hydrate (C-S-H) gel, ettringite (AFT) crystals, and afwillite, enhancing the concrete microstructure. Notably, coal gangue concrete calcined at 800°C exhibited a porosity of 1.29 % and a compressive strength of 38 MPa after 28 days of curing, meeting the C30 concrete standard. Furthermore, the correlation between the compressive strength of CCGC and its microstructure exceeded 0.72, indicating that fractal dimension analysis is an effective method for predicting concrete strength.http://www.sciencedirect.com/science/article/pii/S2214509525004784Calcined coal gangue coarse aggregateConcreteHydration reactionsMicrostructureCompressive strength |
| spellingShingle | Shengpeng Hao Wenyu Xu Bambesiwe M. May Zhenyu Zhang Yuyu Zhang Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate Case Studies in Construction Materials Calcined coal gangue coarse aggregate Concrete Hydration reactions Microstructure Compressive strength |
| title | Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate |
| title_full | Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate |
| title_fullStr | Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate |
| title_full_unstemmed | Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate |
| title_short | Experimental study on the micro-mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate |
| title_sort | experimental study on the micro mechanism and compressive strength of concrete with calcined coal gangue coarse aggregate |
| topic | Calcined coal gangue coarse aggregate Concrete Hydration reactions Microstructure Compressive strength |
| url | http://www.sciencedirect.com/science/article/pii/S2214509525004784 |
| work_keys_str_mv | AT shengpenghao experimentalstudyonthemicromechanismandcompressivestrengthofconcretewithcalcinedcoalganguecoarseaggregate AT wenyuxu experimentalstudyonthemicromechanismandcompressivestrengthofconcretewithcalcinedcoalganguecoarseaggregate AT bambesiwemmay experimentalstudyonthemicromechanismandcompressivestrengthofconcretewithcalcinedcoalganguecoarseaggregate AT zhenyuzhang experimentalstudyonthemicromechanismandcompressivestrengthofconcretewithcalcinedcoalganguecoarseaggregate AT yuyuzhang experimentalstudyonthemicromechanismandcompressivestrengthofconcretewithcalcinedcoalganguecoarseaggregate |