This Standard sets out the method for determining the strength of rock specimens in the field using portable equipment,

This Standard sets out the method for determining the strength of rock specimens in the field using portable equipment. Specimens in the form of either rock core (the ‘diametral’ and ‘axial’ tests) or irregular lumps (the ‘irregular lump’ test) are broken by application of a concentrated load using a pair of conical platens. A point load strength index (Is(50)) is obtained and may be used to classify rocks by strength.NOTES: 1 This test is intended as a simple procedure for field strength classification of rocks. Where necessary, the recommended procedures may be modified to overcome practical limitations, provided such modifications are clearly stated in the report.2 Comparisons of point load strength indices from different rock domains should take into account systematic variations in sample size and shape.3 If a relationship between point load strength index and uniaxial compressive strength is required, the relationship should be established by testing.CAUTION: SOME OF THE TESTS SPECIFIED IN THIS STANDARD INVOLVE THE USE OF PROCESSES THAT COULD LEAD TO A HAZARDOUS SITUATION.

First published as AS 4133.4.1-1993.Second edition 2007.Reconfirmed 2016. Originated as AS 4133.4.1-1993. Second edition 2007.