Call number:
ZSP-202-294
In:
Research report
Description / Table of Contents:
CONTENTS: Introduction. - Test materials. - Testing programs. - Test equipment. - Loading machine. - Environmental chamber. - Platen arrangements. - Stress/strain measurements. - Test procedures. - General. - Uniaxial compressive strength. - Diametral compression tests. - Stress/strain tests. - Test results. - Uniaxial compressive strength. - Brazil tensile strength. - Ring tensile strength. - Stress/strain characteristics. - Discussion. - Strength as a function of water content at room temperature. - Strength as a function of water content at -25°C. - Effect of temperature on the strength of nominally dry rocks. - Effect of low temperature on the strength of water-saturated rocks. - Effect of water on deformability at room temperature. - Deformability of air-dry rock as a function of temperature. - Effect of low temperature on the deformability of water-saturated rocks. - Conclusions and recommendations. - Literature cited. - Appendix A.Test materials for low temperature studies in rock mechanics. - Abstract.
Description / Table of Contents:
Strength tests were made on three types of rock, both "air-dry" and water-saturated, at temperatures from +25° to -195°C, and stress/strain tests were made down to -60°C. Strength of air-dry specimens increased with decreasing temperature at an average rate of approximately 2 x 10^-3 °C^-1, and quasi-elastic moduli increased at comparable rates. Static fatigue mechanisms in air-dry rock were apparently influenced by temperature-modification of adsorbed water. Strength of water-saturated specimens increased dramatically as pore water froze, and continued to increase down to -120°C, where compressive and tensile strengths were greater than room temperature values by factors of 5, 4 and 2 for sandstone, limestone and granite respectively. Compressive stress/strain curves for saturated rocks became steeper after freezing, and initial tangent moduli for saturated high porosity rocks increased by well over an order of magnitude.
Type of Medium:
Series available for loan
Pages:
v, 75 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 294
URL:
http://www.worldcat.org/oclc/5861472
Language:
English
Branch Library:
AWI Library
