Mechanical and transport properties of rocks at high temperatures and pressures. Task II: fracture permeability of crystalline rocks as a function of temperature, pressure, and hydrothermal alteration

The kinetic theory of gases can be used to accurately calculate the transport properties of gases based on knowledge of the intermolecular potential between the interacting atoms, molecules or ions. This approach has been especially useful at high temperatures where experimental transport data are either sparse or unavailable. In recent years, increasingly accurate potentials for atom-atom and atom-ion interactions have become available for such calculations, and approaches for applying these potentials to calculate the high temperature thermophysical properties of gases are described.

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TRANSPORT PROPERTIES OF PURE METALS AT HIGH TEMPERATURES: I. COPPER

Canadian Journal of Physics ◽

10.1139/p67-309 ◽

1967 ◽

Vol 45 (11) ◽

pp. 3677-3696 ◽

Cited By ~ 39

Author(s):

M. J. Laubitz

Keyword(s):

High Temperature ◽

Transport Properties ◽

High Temperatures ◽

Pure Copper ◽

High Temperature Properties ◽

Temperature Range ◽

Pure Metals

This paper is the first of a series reporting our investigations into the high-temperature properties of the monovalent metals. It contains a description of the methods used in these investigations, and the results of measurements of the transport properties of pure copper, over the temperature range 300–1 250 °K. These results are compared with some previously published work, and also with standard theoretical expressions applicable to the monovalent metals.

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Pore volume and transport properties changes during pressure cycling of several crystalline rocks

Mechanics of Materials ◽

10.1016/0167-6636(86)90021-9 ◽

1986 ◽

Vol 5 (3) ◽

pp. 235-249 ◽

Cited By ~ 20

Author(s):

Yves Bernabe

Keyword(s):

Transport Properties ◽

Pore Volume ◽

Crystalline Rocks ◽

Pressure Cycling

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Carrier generation and transport properties of heavily Nb-doped anatase TiO2 epitaxial films at high temperatures

Journal of Applied Physics ◽

10.1063/1.2362990 ◽

2006 ◽

Vol 100 (9) ◽

pp. 096105 ◽

Cited By ~ 134

Author(s):

Daisuke Kurita ◽

Shingo Ohta ◽

Kenji Sugiura ◽

Hiromichi Ohta ◽

Kunihito Koumoto

Keyword(s):

Transport Properties ◽

High Temperatures ◽

Epitaxial Films ◽

Anatase Tio2 ◽

Carrier Generation

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Transport Properties and Resistance Improvement of Ultra-High Performance Concrete (UHPC) after Exposure to Elevated Temperatures

Buildings ◽

10.3390/buildings11090416 ◽

2021 ◽

Vol 11 (9) ◽

pp. 416

Author(s):

Yunfeng Qian ◽

Dingyi Yang ◽

Yanghao Xia ◽

Han Gao ◽

Zhiming Ma

Keyword(s):

Compressive Strength ◽

Transport Properties ◽

High Temperatures ◽

High Performance ◽

High Performance Concrete ◽

Ultrasonic Pulse Velocity ◽

Ultrasonic Pulse ◽

Pulse Velocity ◽

Capillary Absorption ◽

Self Healing

Ultra-high performance concrete (UHPC) has a high self-healing capacity and is prone to bursting after exposure to high temperatures due to its characteristics. This work evaluates the damage and improvement of UHPC with coarse aggregates through mechanical properties (compressive strength and ultrasonic pulse velocity), transport properties (water absorption and a chloride diffusion test), and micro-properties such as X-ray diffraction (XRD), Mercury intrusion porosimetry (MIP), and Scanning electronic microscopy (SEM). The result demonstrates that polypropylene (PP) fibers are more suitable for high temperature tests than polyacrylonitrile (PAN) fibers. The result shows that 400 °C is the critical temperature point. With the increase in temperature, the hydration becomes significant, and the internal material phase changes accordingly. Although the total pore volume increased, the percentage of various types of pores was optimized within 400 °C. The mass loss gradually increased and the ultrasonic pulse velocity gradually decreased. While the compressive strength first increased and then decreased, and the increase occurred within 25–400 °C. As for the transport properties, the chloride migration coefficient and capillary absorption coefficient both increased dramatically due to the higher sensitivity to temperature changes. The results of the property improvement test showed that at temperatures above 800 °C, the compressive strength recovered by more than 65% and the ultrasonic pulse velocity recovered by more than 75%. In terms of transport properties, compared to the results before self-healing, the chloride migration coefficient decreased by up to 59%, compared with 89% for the capillary absorption coefficient, after self-healing at 800 °C. With respect to the enhancement effect after exposure to high temperatures, the environment of a 5% Na2SO4 solution was not as good as the clean water environment. The corresponding changes in microstructure during the high temperatures and the self-healing process can explain the change in the pattern of macroscopic properties more precisely.

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