Aggregates

Aggregates should be clean, hard and have good shape. The physical, mechanical and chemical properties of aggregates should be checked regularly. The grading, dust content and flakiness index are used to assess the physical properties. A test frequency of 1 sample per 200 tonnes is recommended.

 

The mechanical properties of aggregates such as, resistance to crushing, abrasion and polishing are assessed using the ACV, AAV and PSV tests. Other relevant tests include the TFV and LAAV. Mechanical properties should be certified twice yearly.

 

The tests used to assess the chemical properties of aggregates include density, soundness and chemical composition.

 

Highway Testing Laboratory Ltd. can sample, test and verify the quality of your aggregates for use in surface dressing and concrete. A list of tests which we perform are listed below:

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Aggregate Tests:

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Aggrgates for Surface Dressing:

Grading

Dust Content

Flakiness Index

Aggregate Crushing Valu (ACV) (14 to 10 mm size)

Aggregate Abrasion Value (AAV) (14 to 10 mm size)

Polished Stone Value (PSV) (10 to 6.3 mm size)

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Aggregates for Concrete:

Grading

Flakiness index

Shell Content

Clay, Silt and Dust Content

Aggregate Crushing Value (ACV)

Ten Percent Fines Value (TFV)

Los Angeles Abrasion Value (LAAV)

Aggregate Density and Water Absorption

Chloride Ion Content

Sulphate Content

Aggregate Soundness

Drying Shrinkage

Chemical and Petrographic Analysis

 

The standard tests for assessing aggregates for surface dressing are performed in accordance with B.S. 812 "Testing Aggregates" and the Department of the Environment "Surface Dressing" book. Concrete aggregates are tested in accordance with I.S. 5 "Aggregates for Concrete".

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