uniaxial
Department of Civil Engineering
CIVL 2002 Engineering Geology & Rock Mechanics
(2013-2014, Semester 1)
Laboratory Session 2
BRAZILE TEST
XING BODONG
3035022904
Subclass Group C
November 10, 2013
The University of Hong Kong
Abstract The Brazil test is intended to measure the uniaxial tensile strength of prepared rock specimens indirectly. It is an indirect tensile testing of rock. The Brazil test provides an alternative to direct tensile testing, producing tensile failure in the end faces of cylindrical rock samples by subjecting these specimens to compressive force along their length. The testing machine used is DMG loading machine, which is shown in Fig.1. The test specimens shall be right circular cylinders having a height to diameter ratio of 1.0:2.0 and a diameter preferably of not less than NX core size, approximately 54 mm. The test specimens should be cut and prepared using clean water. The cylindrical surfaces should be free from obvious tool marks and any irregularities across the thickness of the specimen should not exceed 0.025 mm. End faces shall be fiat to within 0.25 mm and square and parallel to within 0.25°. The test specimen shall be wrapped around its periphery with one layer of the masking tape and mounted squarely in the test apparatus such that the curved platens load the specimen diametrally with the axes of rotation for specimen and apparatus coincident. Load on the specimen shall be applied continuously at a constant rate such that failure in the weakest rocks occurs within 15-30s. A loading rate of 200 N/s is adopted in this experiment. The specimen is placed horizontally and loaded in compression until the flat ends split, revealing important tensile strength data. In this experiment, the Brazil test is carried out in accordance to: Suggested Methods for Determining Tensile Strength of Rock Materials. The purpose of this test is mainly for measuring the uniaxial tensile strength
CIVL 2002 Engineering Geology & Rock Mechanics
(2013-2014, Semester 1)
Laboratory Session 2
BRAZILE TEST
XING BODONG
3035022904
Subclass Group C
November 10, 2013
The University of Hong Kong
Abstract The Brazil test is intended to measure the uniaxial tensile strength of prepared rock specimens indirectly. It is an indirect tensile testing of rock. The Brazil test provides an alternative to direct tensile testing, producing tensile failure in the end faces of cylindrical rock samples by subjecting these specimens to compressive force along their length. The testing machine used is DMG loading machine, which is shown in Fig.1. The test specimens shall be right circular cylinders having a height to diameter ratio of 1.0:2.0 and a diameter preferably of not less than NX core size, approximately 54 mm. The test specimens should be cut and prepared using clean water. The cylindrical surfaces should be free from obvious tool marks and any irregularities across the thickness of the specimen should not exceed 0.025 mm. End faces shall be fiat to within 0.25 mm and square and parallel to within 0.25°. The test specimen shall be wrapped around its periphery with one layer of the masking tape and mounted squarely in the test apparatus such that the curved platens load the specimen diametrally with the axes of rotation for specimen and apparatus coincident. Load on the specimen shall be applied continuously at a constant rate such that failure in the weakest rocks occurs within 15-30s. A loading rate of 200 N/s is adopted in this experiment. The specimen is placed horizontally and loaded in compression until the flat ends split, revealing important tensile strength data. In this experiment, the Brazil test is carried out in accordance to: Suggested Methods for Determining Tensile Strength of Rock Materials. The purpose of this test is mainly for measuring the uniaxial tensile strength
References: Brumbach, Michael E.; Clade, Jeffrey A. (2003), Industrial Maintenance, Cengage Learning, pp. 112–113, ISBN 978-0-7668-2695-3. Sobel, Dava (1995). Longitude. London: Fourth Estate. p. 103. ISBN 0-00-721446-4. "A novel antifriction device that Harrison developed for H-3 survives to the present day – ...caged ball bearings." Ball bearing. Retrieved on Oct. 13th, 2013. Francis, D. Au. (2013). Theory and design of structures I: arches. Hong Kong: The University of Hong Kong. Francis, D. Au. (2013). Lab sheet: horizontal abutment thrust of three-hinge arch. Hong Kong: The University of Hong Kong. http://www.academia.edu/4701909/Brazil_report_jenny http://www.ejge.com/2012/Ppr12.351alr.pdf