Abstract
The purpose of this study is to investigate the displacement of coal gangue filling material in road construction and microstructural behavior of treated coal gangue by considering the environmental factors of aqueous solutions with different acidity. The displacement analysis of the coal gangue embankment model has been done by means of the finite element method PLAXIS. Furthermore, using the scanning electron microscope, the energy dispersive system, and the Raman spectrometer to analyze the microscopic mechanism in the view of microstructure, elements, the integrity of carbon structure and the stability of chemical bonds of coal gangue. The results show that the larger displacement of the treated coal gangue subgrade is within 4.0 m below the top of the subgrade, and the maximum displacement value is about 7 mm, which is less than the displacement of untreated coal gangue sample. While the treated A-CG and T-CG grain size, surface area and internal friction angle increase, the unstable carbon structure is destroyed, so its shear strength, compression performance, and consolidation effect are improved. S-CG particles are coated with Na-Si-Al gel, which enhances the density, viscosity and shear strength, thus ensuring the stability of the coal gangue subgrade. The treated coal gangue subgrade slope foot displacement, boundary shear stress and safety factor are all meet the specification requirements.
Highlights
Coal gangue (CG), a mine tailing discharged during the process of coal mining and washing, is a kind of black-gray rock with low carbon content and it is harder than coal in the formation of the coal
The purpose of this study is to determine the final displacement of road embankment considering filling materials treated in different acidity solutions and evaluate the effect of an aqueous environment
The main conclusions are is analyzed via Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) and Raman spectra from the view of microscopic
Summary
Coal gangue (CG), a mine tailing discharged during the process of coal mining and washing, is a kind of black-gray rock with low carbon content and it is harder than coal in the formation of the coal. In order to enhance the utilization rate of CG, many scholars have studied the properties of CG and found the performance of CG is reliable when using it directly or combined with other road materials [6,7,8,9,10,11]. The main factors affecting the subgrade stability are the components of the coal gangue, the additive materials, the optimum water contents, the subgrade structures, the construction compaction, loads, etc. For the purpose of improving its stability, a huge number of studies start from physical methods, by controlling the filling height, impact and strong compaction, or incorporation additives, such as lime, cement, fly ash, red mud, or asphalt [12,13,14,15,16]. Coal gangue with a large amount of organic matter can be affected by different acidity solutions
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
