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GD TEST prove, indagini e monitoraggi per la geoingegneria

CERCHAR Abrasiveness Test

(Centre d'Études et Recherches des Charbonnage de France)


Abrasiveness is one of the properties of rocks that is measured in order to assess their suitability for mechanical excavation.

The CERCHAR abrasiveness test for rock is widely used for estimated performances of Tunnelling Boring Machines (TBM).

The rock is slowly displaced by 10mm. The abrasiveness of the rock is optained by measuring the resulting wear flat on the steel cone. the unit of abrasiveness is defined as a wear flat of 0.1mm diameter.

CERCHAR Abrasivity Index
(CAI) for various rocks

Rock type

CAI

Location

Shale

0.9

New York

Shale

1.1

Ohio

Limestone

1.1

Illinois

Barea Sandstone

1.2

Ohio

Indiana Limestone

1.3

Indiana

Phyllite

1.3

Norway

Mica Schist

2.2

Washington, D.C.

Andesite

2.3

Arizona

Quartz Diorite

3.2

Norway

Red Sandstone

3.6

Kentucky

Anphibolite

3.6

Norway

Gabbro

3.7

Norway

Granediorite

3.9

North Carolina

Granite

4.0

Sweden

Diorite

4.1

North Carolina

Gneiss

4.1

Georgia

Quartz Gneiss

4.3

Georgia

Quartzite

4.3

East Africa

Gneiss

4.4

Norway

Sandstone

4.7

Kentucky

Quartz Gneiss

4.8

Norway

Granite Gneiss

4.8

Norway

Mica Schist

5.3

New York

Quartzite

5.9

Norway
Abrasiveness test Apparatus
CERCHAR Abrasivity Index
CAI on Calculated Quartz equivalence


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