Engineering Properties of Coal Ash Made Granulated Particles as Backfill Material
| Autor: | Jun-Hao Huang, 黃俊豪 |
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| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Different granulated methods were studied in this research to reduce the particles segregation problem of hydraulically dumped coal ash mixture in the water. So, the strength uniformity of backfilled coal ash can be enhanced. The coal ash used in the laboratory test was taken from the ash pond of Linkou Power Plant at different distances from the outlet of ash pipes discharging pipeline. Since the Linkou coal ash mainly consists of coarse particles, a small amount of fine fly ash was added to the coal ash mixture to improve its cohesive property and to facilitate the laboratory experiments. To evaluate the feasibility of making particulate backfill material from Linkou coal ash and fly ash, the following parameters testes were adopted: curing method and curing time, unconfined compressive strength, California Bearing Ratio (CBR), modified Proctor test, consolidation test and direct shear test. The particles segregation was also observed from a model hydraulic filling test. The test results show that the fines content in the coal ash mixture is significantly reduced after granulation. So does the particles segregation during hydraulic backfilling. After the cemented coal ash hardened, it was broken into smaller pieces by hammer; or the coal ash mixture was pushed through a sausage maker and produced small hot-dog like cemented coal ash backfilled material. The laboratory test results show that the physical properties of cemented coal ash are not affected by different curing methods or curing time; but the mechanical properties will vary depend on the curing methods and curing time. Finally, the benefit of the granulated coal ash mixture will be compared with coal ash or coal ash mixture in terms of performance. It is hoped that coal ash removal and recycling process can be significantly improved by means of the coal ash granulation method proposed in this study. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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