Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inducing tensile failure of claystone through thermal pressurization in
  a novel triaxial device   Complex coupled thermo-hydromechanical (THM) loading paths are expected to
occur in clay rocks which serve as host formations for geological radioactive
waste repositories. Exothermic waste packages heat the rock, causing thermal
strains and temperature induced pore pressure build-up. The drifts are designed
in such a way as to limit these effects. One has to anticipate failure and
fracturing of the material, should pore pressures exceed the tensile resistance
of the rock. To characterise the behaviour of the Callovo-Oxfordian claystone
(COx) under effective tension and to quantify the tensile failure criterion, a
laboratory program is carried out in this work. THM loading paths which
correspond to the expected in situ conditions are recreated in the laboratory.
To this end, a special triaxial system was developed, which allows the
independent control of radial and axial stresses, as well as of pore pressure
and temperature of rock specimens. More importantly, the device allows one to
maintain axial effective tension on a specimen. Saturated cylindrical claystone
specimens were tested in undrained conditions under constrained lateral
deformation and under nearly constant axial stress. The specimens were heated
until the induced pore pressures created effective tensile stresses and
ultimately fractured the material. The failure happened at average axial
effective tensile stresses around 3.0 MPa. Fracturing under different lateral
total stresses allows one to describe the failure with a Hoek-Brown or
Fairhurst's generalized Griffith criterion. Measured axial extension strains
are analysed based on a transversely isotropic thermo-poroelastic constitutive
model, which is able to satisfactorily reproduce the observed behaviour.

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The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom