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Full-Text Articles in Engineering
Preparation And Characteristics Of Inorganic Curing Foam With Large-Volume Fly Ash In Goaf, Ma Li, Du Su, Zhang Zhaoyun, Wang Hui, Zhao Liang, Zhang Bo
Preparation And Characteristics Of Inorganic Curing Foam With Large-Volume Fly Ash In Goaf, Ma Li, Du Su, Zhang Zhaoyun, Wang Hui, Zhao Liang, Zhang Bo
Coal Geology & Exploration
Air leakage in the goaf of coal mine is an important cause of coal fire disaster. The traditional filling and plugging materials are easy to crack, with poor fluidity and high cost. Therefore, it is necessary to develop new materials for effective filling and plugging of the air leakage channels. Herein, the new filling and plugging material of inorganic curing foam with large-volume fly ash was developed by optimizing the mix ratio based on material fluidity, initial setting time and compressive strength using the single factor variable method. Meanwhile, the material hydration process was characterized by the infrared spectroscopy, X-ray …
Brittle Compressive Failure Of Salt-Water Columnar Ice Under Biaxial Loading, T. R. Smith, E. M. Schulson
Brittle Compressive Failure Of Salt-Water Columnar Ice Under Biaxial Loading, T. R. Smith, E. M. Schulson
Dartmouth Scholarship
The brittle failure of saline columnar ice was investigated under biaxial compression at and −10° and −40°C over the range 0 ≤ R A < 1 where R A is the ratio of the intermediate to major principal compressive stress. The major principal stress and the intermediate (confining) stress were orthogonal to the columnar axes (type-A confinement); both stresses and the c-axes of the grains were co-planar. The results confirm earlier work by Hausier (1981) and Timco and Frederking (1983, 1986) on saline ice and follow similar behavior to fresh-water columnar ice found by Smith and Schulson (1993) and Frederking (1977). Failure stress and failure mode are sensitive to the confinement and two regimes of behavior are found: the failure stress first rapidly increases with R A in the range 0 ≤ R A < R T and then tends to decrease for R A > R t. The transition stress ratio, R t changes from ≈0.2 at −10°C to ≈0.1 at −40°C. The failure mode changes from axial splitting to shear faulting in the loading plane for 0 < R A < R t. Above R t failure changes to a combined mode of splitting across the columns and shear faulting out of the loading plane. The failure-stress envelope is of a truncated Coulomb-type. Damage studies show wing cracks and local fragmentation of grains involving the brine pockets. The results are explained in terms of Coulombic sliding and Hertzian crack mechanics.