Aggregate abrasion value test

At least 24 aggregate particles are placed in a steel mould in a single layer with their flattest surface down. The interstices between the aggregates are in-filled with fine sand to approximately three quarters of their depth. The rest of the mould is in-filled with epoxy resin, and a metal plate, which has been precoated with grease, is placed on top. After the resin hardens, the specimen is removed from the mould, cleaned thoroughly from any sand and transferred to the abrasion machine. 

After completion of the test, the specimens are cleaned thoroughly and weighed with an accuracy of 0.1 g. 

The AAV index is calculated in reference to the loss of weight of the specimen using the 

AAV limiting values relate to traffic volume. The limiting values proposed by the UK Highways Agency are given in Table 2.11. 

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Other mechanical test procedures are given in BS 812, namely the aggregate crushing value, aggregate abrasion value and the polished stone value. Other tests are widely used, such as the Los Angeles test for impact resistance [8.6]. 

Aggregate abrasion value (AAV) is (he resistance of an aggregate to abrasion, as measured by the aggregate abrasion test. Low values indicate increased res-isUmce to abrasion. 

Other geometrical and physical tests on the aggregates of the RA (angularity, resistance to fragmentation, resistance to polishing polished stone value [PSV], resistance to surface abrasion aggregate abrasion value [AAV], particle density, water absorption, etc.) may also be necessary to be determined when comprehensive mix design is followed. 

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