Laboratory · Aggregates for concrete, asphalt and roads
Aggregate makes up around three quarters of concrete and over 90% of asphalt by mass. Its grading, shape, cleanliness and hardness decide workability, strength and durability long before cement or bitumen are added.
We test sand, gravel and crushed stone for quarries, concrete and asphalt plants, contractors and supervisors. All eleven tests below are accredited under ISO/IEC 17025 (DPA certificate LT 069).
When you need these tests
- Approving a new quarry or source for concrete or asphalt.
- Factory production control and CE declarations for aggregate producers.
- Road base, sub-base and wearing course materials that must meet Los Angeles and shape limits.
- Investigating poor workability, high water demand or low strength in concrete.
Accredited tests and standards
Grading, shape and cleanliness
| Test | What it tells you | Range | Standard | Where |
|---|---|---|---|---|
| Particle size distribution (sieve analysis) | Grading curve: checks the aggregate against the specified envelope and mix design | 0.063–150 mm | BS EN 933-1:2012; AASHTO T27:22; ASTM C136/C136M-19 | Laboratory |
| Shape index | Proportion of non-cubical particles that reduce workability and strength | 0–100% | BS EN 933-4:2008 | Laboratory |
| Flakiness index | Flat particles that weaken concrete and asphalt and break under traffic | 0–100% | BS EN 933-3:2012 | Laboratory |
| Elongation index | Elongated particles that affect packing and workability | 0–100% | BS 812-105.2:1980 | Laboratory |
| Assessment of fines – sand equivalent | Detects harmful clay and dust in sand that raise water demand | 1–98% | BS EN 933-8:2012+A1:2015; ASTM D2419-22 | Laboratory |
Density and absorption
| Test | What it tells you | Range | Standard | Where |
|---|---|---|---|---|
| Particle density and water absorption | Needed to calculate mix proportions and water demand; high absorption flags weak or porous material | density 2.1–3.0 g/cm³; absorption 0.1–10% | BS EN 1097-6:2022; ASTM C128-22; ASTM C127-15; BS EN 1097-7:2022 | Laboratory |
| Loose bulk density | Converts between mass and volume for batching and stockpile control | 1.1–1.9 g/cm³ | BS EN 1097-3:1998 | Laboratory |
Mechanical and durability
| Test | What it tells you | Range | Standard | Where |
|---|---|---|---|---|
| Resistance to fragmentation (Los Angeles) | Hardness and resistance to wear and impact: key for road and railway aggregate | 1–100% | BS EN 1097-2:2020; ASTM C131/C131M-20 | Laboratory |
| Aggregate crushing value (ACV) | Resistance to crushing under a gradually applied load | 1–100% | BS EN 1097-2:2020 | Laboratory |
| Magnesium sulfate soundness (10/14 mm) | Durability against salt crystallisation and weathering | 0.5–30% | BS EN 1367-2:2009 | Laboratory |
| Resistance to freezing and thawing | Durability in climates with frost | ≥ 0.05% | BS EN 1367-1:2007 | Laboratory |
Sampling and what to send us
- About 25–50 kg per sample depending on the maximum size and the tests requested.
- Separate bags per fraction (e.g. 0/4, 4/8, 8/16), labelled with source and date.
- We can sample from stockpiles or the conveyor on request.
What your test report contains
- A unique report number, the accredited laboratory’s details and the ISO/IEC 17025 accreditation mark for accredited tests.
- Sample identification, sampling details and the condition of the sample on receipt.
- The standard and method used for every test, with any deviation stated.
- Results with units, and comparison with the specified limits when you give them to us.
- Signature of the authorised laboratory staff.
Frequently asked questions
Which tests does concrete aggregate need?
Typically grading, particle density and absorption, fines (sand equivalent) and shape. For exposed concrete, add soundness or freeze–thaw.
What is the Los Angeles test for?
It measures resistance to fragmentation. Road, railway ballast and asphalt specifications set a maximum LA value, so it is the key acceptance test for those uses.
Related testing
Tell us the material, the quantity of samples and the specification you are working to. We’ll confirm the tests, the sampling and the price.