AS 4133.4.3.2:2013 pdf free download – Methods of testing rocks for engineeringpurposes Method 4.3.2: Rock strength tests— Determination of the deformability of rock materials in uniaxial compression-Rockstrength less than 50 MPa

AS 4133.4.3.2:2013 pdf free download – Methods of testing rocks for engineeringpurposes Method 4.3.2: Rock strength tests— Determination of the deformability of rock materials in uniaxial compression-Rockstrength less than 50 MPa.
4.2 Specimen preparation
The test specimen shall be prepared as folIos:
(a) From a suitable sample prepare a Lest specimen having the following characteristics:
(i) Test specimen shall be a straight circular cylinder having a length to diameter ratio of betcen 2.5 and 30 and a diameter preferably of not less than 45mm. The diameter of the specimen shall be at least ten limes the size of the largest grain in the rock.
NOTE: While S test specimen length to diameter ratio in thc range of 2.5 to 3.0 is specilied. in accordance with that recommended by ISRM. it is recognized that there is evidence suggesting that a minimum length to diameter ratio of 2.0 may be adequate paflicularly for rocks ssith strength less than 25 NIPs. Therefore. sshilc a ratio of hetsee-n 2.5 to 3.0 is preferred, it is possible to es.tend this range to bctcen 2.0 and 3.0 to alloss additional testing where the core lengths are limited, Where the ratio is lcss than 2.5. ii should bc noted in the test report.
(ii) The ends of the specinien shall be cut parallel to each other to within V and at right angles to the sides of the specimen to within IC.
(iii) The ends of thc specimen shall be ground flat to 0.1 mm across the face with no surface irregularities. If the ends of the specimen cannot be ground or contain surface irregularities they may be capped using a capping material that has a strength greater than 50 MPa.
(iv) The sides of the specimen shall bc free of abrupt irregularities and straight over the full length of the specimen.
(b) Determine the average original diameter of the specimen to at least the nearest 0.1 mm across two diameters at right angles and at the centre and near the top and bottom of the specimen. Calculate the average original diameter (di.) of the test specimen from the six measurements.
(c) Measure and record the height of the specimen to 0.1 mm.
(d) If required. moisture condition the specimen prior to testing.
S TEST PkOCFIflIRF
The procedure shall be as foIlos:
(a) Attach the measuring devices to the specimen.
(b) Load the specimen continuously and without shock. Apply the load to achieve a displacement rate of no greater than 0.1 rnm.’min, Plot load and displacement using the continuously recording device until a load deflection curse has been established sufficiently to permit the calculation of the Young’s modulus and Poisson’s ratio detailed in Clause 6. When performing the test using cxtcnsometcrs where destruction of the measuring devices may occur at specimen failure, the devices may be removed when at least 70°/. of the estimated strain to failure has been reached. Care should be taken to ensure that the load is maintained such that only minor relaxation of the sample occurs before loading to failure.
NOTES:
I it is desirable that the rate of loading be adjusted to achieve failure of the specimen between 10 and iS minutes. pros idcd that this rate of loading does not exceed a displacement rate of 0.1 mmmin.
2 Where it is required to perfonn multiple cycles of loading and unloading, a suitable maximum load for the cycle may be taken as half the estimated failure load.
7 TEST REPORT
The following shall be reported:
(a) The uniaxial compressive strength, in MPa, expressed to two significant figures.
(b) Young’s modulus, in GPa. expressed to two significant figures.
(e) Poisson’s ratio, expressed to two significant figures.
(d) Methods of determination of Young’s modulus and the axial stress level or levels at which they were determined.
Ic) Graphical presentation of axial and dianietral stress strain cunes. See Figure I.
(f) l)escription of failure.
NOTE: Appendix B provides guidance on failure dcriptions
(g Photographs of the test specimen before testing and after failure.
(h) Source and identification ikock Type) of test specimen.
(i) Storage history, curing and environment.
(j) Date oltesting.
(k) Average specimen diameter and height in millimetres to the nearest 0.1 mm and the length to diameter ratio of the test specimen.
(I) Moisture content of the specimen to the nearest 0,1%.
(m) Rate of displacement and test duration.
(n) Any other pertinent observations.
tot Reference to this test method. i.e. AS 4133.4.3.2.