Swelling experiments on mudstones

The swelling properties of limestone and sandstone at 300 ℃ to 700 ℃ were investigated by the experiment system used to measure the swelling properties of rocks at high temperature and designed by ourselves.The experimental results show that the swelling stresses of limestone and sandstone increase with temperature increasing during raising temperature;and the swelling velocity of sandstone is more quickly than the limestone.The swelling stress of sandstone is 2.45 times as that of limestone when just reaching to 700 ℃.The fitted functions of curves about swelling stress and temperature are second-degree parabolaes during raising temperature;and the related coefficients are all above 0.94.The swelling stresses of two kinds of rocks increase slowly during constant temperature with time prolonging and tended to steady values at last.Two kinds of rocks' swelling stresses reach to the limit values at 600 ℃;but the specific processes are different.The swelling stress of sandstone is 3.14 times as that of limestone when constant temperature process finished at 700 ℃.The swelling stress of rock is obviously related to lithological characters,mineral resolving,porosity and sound velocity.

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Swelling and osmotic flow in a potential host rock

Physics and Chemistry of the Earth Parts A/B/C (2006)

S.T. Horseman J.F. Harrington D.J. Noy

Distilled water

Osmotic pressure

10.1016/j.pce.2006.05.003

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Citations (36)

Sealing of fractures in claystone

Journal of Rock Mechanics and Geotechnical Engineering (2013)

Chun-Liang Zhang

The sealing behavior of fractures in clay rocks for deep disposal of radioactive waste has been comprehensively investigated at the GRS laboratory. Various sealing experiments were performed on strongly cracked samples of different sizes from the Callovo-Oxfordian argillite and the Opalinus clay under relevant repository conditions. The fractured samples were compacted and flowed through with gas or synthetic pore-water under confining stresses up to 18 MPa and elevated temperatures from 20 °C to 90 °C. Sealing of fractures was quantified by measurements of their closure and permeability. Under the applied thermo-hydro-mechanical (THM) conditions, significant fracture closure and permeability decrease to very low levels of 10−19 to 10−21 m2 were observed within time periods of months to years. The properties of the resealed claystones are comparable with those of the intact rock mass. All test results suggest high sealing potentials of the studied claystones.

10.1016/j.jrmge.2013.04.001

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Citations (64)

Desorption and consolidation behaviour of initially saturated clays

CRC Press eBooks (2010)

Snehasis Tripathy Ramakrishna Bag Howard P. Thomas

One-dimensional consolidation and desorption behaviour of highly plastic clays (MX 80 bentonite and Speswhite kaolin) were experimentally determined in this study. Initially saturated clay specimens were subjected to an increase in suction employing axis-translation technique and salt-solution technique to cover a suction range of 10 kPa to 300 MPa. Consolidation tests were carried out with a maximum applied vertical pressure of 3.2 MPa. The water content and the volume of the clay specimens at each applied suctions were measured. The study revealed that a vertical pressure increase was more effective in reducing the water content and the void ratio for the bentonite studied, whereas a suction increase was more effective in removing water from the kaolinite. The possible structure and fabric of the clays at saturation, at commencement of desaturation, and at residual shrinkage stage are discussed. The observed differences in the volume change and water retention behaviour were attributed to the differences in the mineralogical properties of the clays. vertical pressure, and isotropic loading conditions. Marcial et al. (2002) compared the volume change behaviour of bentonites due to an increase in the vertical pressure and suction. Fredlund (1964) and Flereau et al. (1993) noted that an increase in the vertical pressure and suction have similar influence on the volume change behaviour of expansive clays for a large range of applied suction. Marcial et al. (2002) stated that due to isotropic loading conditions, the void ratio decrease due to a suction increase was greater than that obtained due to a vertical pressure increase. Fredlund and Rahardjo (1993)’s results on silty clay (Fig. 1) showed that the volume change behaviour

Consolidation

10.1201/b10526-52

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Influence of Water Content on the Mechanical Properties of an Argillaceous Swelling Rock

Rock Mechanics and Rock Engineering (2016)

Maximiliano R. Vergara Theodoros Triantafyllidis

Saturation (graph theory)

Degree of saturation

10.1007/s00603-016-0938-8

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Citations (76)