Slake Durability Test

This test method covers the determination of the slake durability index of shales and other weak rocks after two drying and wetting cycles with abrasion. The slake durability index is used to estimate qualitatively the probable amount of deterioration of weak rocks, over a period of time, after simulated exposure to natural wetting and drying cycles (e.g. estimating the potential severity of air slaking or invert gradation during tunnel construction).
If the test is conducted according to the DGGT Recommendation No. 20, up to six cycles are performed on the material.

Equipment: Slake Durability Apparatus — HM-4100 (Humboldt Co.)

Reference Standard: ASTM D4644; DGGT Recommendation No. 20