Abstract
Gangue materials have been used to solve mine disasters with a support tunnel along the goaf and filling mining. Mastering the properties and damage characteristics of filling materials is an important basis for effective implementation. Based on the conventional uniaxial compression acoustic emission (AE) test, the effects of cementitious materials, ratio between water and cementitious material, gangue particle size, and grading parameters on the mechanical properties of gangue-cement samples were analyzed. The stage characteristics of compression deformation were studied. The fracture propagation characteristics and rock mass failure types induced by different graded gangues were revealed. The fracture forming mechanism from clustered damage and failure was interpreted. The results show that the compressive strength of the backfill increases with the increase of cementitious material; however, it decreases with the increase of water binder ratio. Controlling the proportion and dosage of materials was the key factor to realizing pumpability and stability. Combined with the deformation and AE characteristics, the failure stage of the backfill body is divided into three stages: linear deformation-low energy changing, block compression-high energy changing, and gentle stability-stable energy changing. Affected by the gangue distribution, the load in each stage will induce fracture to produce five distribution modes of single, turning, breakthrough, bifurcated, and collapsed surrounding gangue. In the process of loading failure, different gradation and particle sizes will also change its stress concentration characteristics, resulting in the transformation of rock failure types. The surface structure and roughness of gangue play an important role in the compressive performance of cement paste. The research results try to provide some guidance for efficient filling mining.
Highlights
With the increasing demand of economic development for energy and infrastructure projects, the instability of deep engineering, such as mines and tunnels, has become an important factor restricting safe development
The cost of backfill will increase, which must be taken into account when determining the material specification [34]. ese studies are only aimed at the elaboration of experimental phenomena and the determination of reasonable gangue particle size and gradation by experiments without further analysis and discussion. erefore, Chen et al studied the influence of red mud, chloride, and other materials on the strength of coal gangue-cemented paste filling from a micro point of view based on mechanical experiments and electron microscope scanning [35, 36]
To reveal the mechanical properties and failure characteristics of the gangue-cement backfill, the influence of cementitious materials and gangue grading parameters were analyzed using the conventional uniaxial compression acoustic emission (AE) test. e failure characteristics and fracture propagation law under stress would be explained. en, it will provide some theoretical support for mine safety mining
Summary
With the increasing demand of economic development for energy and infrastructure projects, the instability of deep engineering, such as mines and tunnels, has become an important factor restricting safe development. According to the research results at this stage, it is considered that the main factors affecting the strength of the filling body are the amount of cement, aggregate particle size composition, water consumption, curing age, mixing time, and curing environment, and the first four factors are the most important. Li et al used PFC3D software to simulate the compression deformation of four different particle size grades of coal gangue filling materials [30]. Erefore, Chen et al studied the influence of red mud, chloride, and other materials on the strength of coal gangue-cemented paste filling from a micro point of view based on mechanical experiments and electron microscope scanning [35, 36]. To reveal the mechanical properties and failure characteristics of the gangue-cement backfill, the influence of cementitious materials and gangue grading parameters were analyzed using the conventional uniaxial compression AE test. To reveal the mechanical properties and failure characteristics of the gangue-cement backfill, the influence of cementitious materials and gangue grading parameters were analyzed using the conventional uniaxial compression AE test. e failure characteristics and fracture propagation law under stress would be explained. en, it will provide some theoretical support for mine safety mining
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
