CERCHAR ABRASIVITY INDEX TEST ON ROCK SAMPLE - ASTM D7625-10

Relative standard : ASTM D7625-10 

The abrasivity of rock and soil is a factor of significant importance for excavation in tunneling, underground construction, mining or quarrying. Abrasion can be defined as wearing or tearing away of particles and material from the solid surface. The CERCHAR abrasivity test is a laboratory method to quantify the rock abrasivity. It allows to determine an index called CERCHAR Abrasivity Index (CAI) for the rock's abrasivity which can be used for evaluate the wear of excavation equipment in different application such as mining, tunneling and drilling.

How it is used : 

1. The rock samples is placed in the machine and tighten with the jaws
2. One pointed noddle is placed on the sample
3. Static load is applied (70 Newton)
4. 10 mm scratch is made on the rock sample in 1 second
5. After that the needle is observed in the microscope to check the revised height "D" (Supplied without Microscope)
6. "D" X 10 will be the abrasive index 
7. Microscope can be supplied at extra cost.