Experimental Study on the Basic Properties of a Green New Coal Mine Grouting Reinforcement Material

Abstract

Waste tires are internationally recognized as hazardous waste. Many waste tires storing in the open air for a long time will not only waste the land resources but also pollute the environment after the incineration. Meanwhile, the cumulative accumulation of fly ash in China has also been one of the largest sources of solid waste in coal mines. Under the action of high winds, the accumulated fly ash forms flying dust, which pollutes the environment and endangers human health. Herein, a new type of grouting material for floor reinforcement was developed based on solid waste products using the waste tire rubber particles and fly ash. Using this new material, disaster accidents such as flooding and casualties caused by the inrush of the floor-confined water due to floor fractures, activation, and expansion in the mining process can be greatly reduced, thereby ensuring the safety of coal mine production. The grout body was prepared using a large amount of fly ash, waste tire rubber particles and clay, and mixing additives. The ratio optimization test, uniaxial compressive strength test, permeability characteristic test, stability test, and microanalysis of mine water environment were performed. From the test results, the macrophysical and chemical properties including optimal mix ratio, compressive strength, permeability coefficient, and stability of mine water environment were obtained. The microstructural properties of the grouts were analyzed using scanning electron microscopy microanalysis methods. Considering the situation of the coal floor and attempting to use as many solid waste products as possible, the optimized proportion that can meet the requirements of low cost, high bonds, and dense filling is as follows: 20% of rubber particles, 65% of fly ash, 15% of clay, and 1% of nanosilica. Furthermore, this study can provide scientific reference for large-scale floor grouting reinforcement and large-scale utilization of solid waste products.

New Type of Similar Material for Simulating the Processes of Water Inrush from Roof Bed Separation

“…The paraffin emulsion has good hydrophobicity, and it is an important similar waterproof material. The properties of this new type of similar material were studied using the compressive strength experiment, , the impermeability experiment, , the structural stability experiment, and the microscopic analysis. Finally, the feasibility of this new type of material was verified through a similar simulation experiment, which provided the scientific basis for the prediction and control of water accidents caused by the separation strata.…”

Geotechnical and Shear Behavior of Novel Lunar Regolith Simulants TUBS-M, TUBS-T, and TUBS-I

“…This unconfined yield strength σ c is achieved from a so-called flow locus presenting the dependency of shear stress for beginning flow as a function of normal stress [ 102 , 103 ]. This point is frequently described as uniaxial compressive strength obtained from uniaxial compaction testers [ 104 ]. When reviewing the literature, it is important to note that the results will not be directly comparable because of different stress state conditions in these two measurement systems [ 105 ].…”

Rock Damage Model Coupled Stress–Seepage and Its Application in Water Inrush from Faults in Coal Mines

“…During underground mining activities, the dynamic change of the stress field of the surrounding rock leads to the initiation and expansion of fractures. The existence of faults not only affects the redistribution of the stress field but also may become a potential water diversion channel when connected with mining-induced fractures. − According to incomplete statistics, more than 80% of the mine water inrush accidents in coal mines are related to faults, causing heavy casualties and property losses. Therefore, the faults have become the key factor affecting the prevention and control of water inrush in mines.…”