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AS 4188.8.131.52-2009 pdf free download
AS 4184.108.40.206-2009 pdf free download.Methods of testing rocks for engineering purposes
Method 4.3.1: Rock strength tests Determination of deformability of rock materials in uniaxial compression Strengths of 50 MPa and greater.
(c) A measuring instrument such as vernier, digital or micrometer callipers capable of measuring specimen dimensions to within 0.1 mm.
(d) Electrical resistance strain gauges. linear variable differential transformers (LVDTs), compressorneters, optical devices or other suitable measuring devices, Their design shall be such that the average of two circumferential and two axial strain measurements, equally spaced. can be determined for each increment of load. The devices shall he robust and stable, with strain sensitivity of the order of 5 x l0’.
I Whatever measuring devices are selected, it is recommended that they are calibrated against the known properties of specimen tested in the manner described in Clause 5. A suitable specimen should consist of a right cylinder of aluminium or steel, Such procedure is essential when using devices other than electrical resistance strain gauges.
2 Strain gauges should be bonded to the specimen by an epoxy resin as recommended by the manufacturer of the strain gauges.
rhere electrical resistance strain gauges are used, the length of the gauges over which axial strain is determined shall be at least 10 grain diameters in magnitude and the gauges should not encroach within d/2 of the specimen ends, where 1 is the diameter of the specimen. Circumferential strain shall be determined over a gauge length between 5% and 10% of the circumference of the specimen.
NOTE: Electrical resistance strain gauges should only be used for non-friable, coherent rocks. which permit an effective bond between the gauges and the rock surface. Alternative techniques arc generally necessary for rocks that fall outside this category, or for rocks whose testing moisture content precludes the necessary bond between the gauges and the rock surface.
Where dial micrometers or LVDTS are used for measuring axial or diametral deforniation due to loading, they shall be graduated to read in 0.002 mm units and accurate within 0.002 mm in any 0.02 mm range and within 0.005 mm in any 0.25 mm range. The dial micrometer or LVDTs shall not encroach within d/2 of the specimen ends. The gauge shall be centrally positioned with a gauge length of not less than S.
(e) An apparatus for continuously recording the loads and deformation (optional).
(a) Prepare a specimen having the following characteristics (see Notes to Item 3(d)):
(i) The specimen shall be a straight circular cylinder having a length to diameter ratio of 2.5 to 3.0, and a diameter preferably of not less than 50 mm. AS 4220.127.116.11-2009 pdf free download.
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