Tensile Strength of Rock(IS 10082:1981 — Brazilian Test)
Indirect (Brazilian) tensile strength testing of rock discs per IS 10082 — the tensile parameter controlling rock fracture in tunnel crowns, rock anchors and blast design.
What is the Tensile Strength Test of Rock?
Rock is an order of magnitude weaker in tension than compression — and it is tension that opens fractures in tunnel crowns, under rock anchor plates, in bending rock beams and around blast holes. Direct tension on rock is notoriously difficult, so IS 10082:1981 (Method of Test for the Determination of Tensile Strength by Indirect Tests on Rock Specimens) uses the Brazilian disc method: a core disc loaded in diametral compression fails in tension across the loaded diameter.
Global Lab prepares discs to the standard thickness-to-diameter ratio, loads them between the specified curved jaws at the standard rate, verifies the central-split failure mode, and reports splitting tensile strength per specimen with sample statistics.
How the Tensile Strength of Rock is Conducted
- 1
Disc Preparation
Core discs are cut to the IS 10082 thickness-to-diameter ratio with flat, parallel faces; dimensions are measured. - 2
Mounting in Curved Jaws
The disc is seated in the standard curved loading jaws ensuring diametral line contact. - 3
Diametral Loading
Compressive load is applied across the diameter at the standard rate until the disc splits. - 4
Failure Validation
The failure surface is examined — only central diametral splits are accepted as valid tension failures. - 5
Computation & Reporting
Splitting tensile strength is computed from peak load and disc dimensions; per-specimen and mean values are issued via Autovity QLMS.
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| IS 10082:1981 | Method of Test for the Determination of Tensile Strength by Indirect Tests on Rock Specimens (Reaffirmed) | Brazilian / Indirect Tension | Indian Standard |
| IS 9143:1979 | Method for the Determination of Unconfined Compressive Strength of Rock Materials (Reaffirmed) | Companion Compression Test | Indian Standard |
| ISRM SM | ISRM Suggested Method for Determining Indirect Tensile Strength by the Brazil Test | Supplementary Practice | International |