Original Cerchar abrasiveness index tester (OCAI 70) – ASTM D The OCAI accurately determines the rock abrasivity index (CAI) employed for the. ASTM D Standard Test Method for Laboratory Determination of Abrasiveness of Rock Using the CERCHAR Method Link. Two standards exist for this test method: the French. standard AFNOR NF P () and ASTM. D (). The test is widely.
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Pricing information and quote request on Geotechgate. The abrasivity of rock and soil is a factor of significant importance for excavation in tunnelling, underground construction, mining or quarrying.
Abraison can be defined as wearing or tearing away of particles and material from the solid surface. It allows to determine an index called CERCHAR Abrasicity Index CAI for the rock’s abrasivity which can be used for evaluate the wear of excavation equipment in different application such as mining, tunnelling and drilling.
The testing principle is based on a steel pin with defined geometry and asgm that is scratches the surface of a rough rock sample over a distance of 10 mm under static load of 70 N. There are two equipment design to run the test:. While, in the West design, the rock sample moves under a stationary pin.
The main difference between the two methods is in the duration of the test. Both devices include the following main parts: It should have a diamater of at least 6 mm and the length should be such at the visibile part of th epin is at least 15 mm. The rock sample is placed in the equipment and firmly clamped using a rigid vice.
The device is rigid and also fixed to avoid any lateral movement. The dead load is xstm placed on the top of the pin and the pin is carefully lowered to the rock surface.
The test is then carried out by relative displacement of the pin on the rock surface across 10 mm at given time intervals.
After the test, th epin is carefully removed and the tip flat wear is measured. The Cerchar- Abrasivity-Index CAI is then calculated from the measured diameter of the resulting wear flat on the pin:.
Cerchar Abrasivity test –
Can you edit this page? Send us an email to editor geotechdata. Cerchar Abrasivity test equipment The testing principle is based on a steel pin with defined geometry and hardness that is scratches the surface of a rough rock sample over a distance of 10 mm under static load of 70 N.
There are two equipment design to run the test: The Cerchar- Abrasivity-Index CAI is then calculated from the measured diameter of the resulting wear flat on the pin: Free quote for buying vane shear test equipment: The D625 abrasiveness index. Rock abrasiveness testing for tunnelling. Copyright – Geotechdata.