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:

Aggregates 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)

The standard tests for assessing cold bituminous materials are performed in accordance with the following:

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”