Civil engineering · Material testing
Rock & Aggregate Testing Equipment
Laboratory and field equipment for testing crushed stone, sand, gravel and rock: jaw crushers and riffle samplers for sample preparation, test sieves and sieve shakers for grading, a sand equivalent shaker for fines content, Los Angeles and Micro-Deval abrasion machines and a point load tester for strength and durability, and a pendulum friction tester for skid resistance. Supplied from Cape Town across South Africa and neighbouring countries.
- 10 instruments
- Sampling to skid resistance
- ASTM, EN & SANS 3001 test methods
- Delivery across Southern Africa
Part of Material Testing Machines, alongside compression, universal and cement testing machines.
Definition
What is rock and aggregate testing?
Rock and aggregate testing measures whether crushed stone, gravel, sand or rock is fit for its intended use in concrete, asphalt, road base, railway ballast or construction fill. Tests cover grading (particle size distribution), cleanliness (clay and fines content), strength, resistance to abrasion and impact, and how slippery the finished surface becomes once traffic polishes it. The results are compared with the limits in a project or road authority specification.
1. Preparation & sampling
Crush rock or core to size, then split the field sample into a representative test portion. A biased sample makes every later result wrong.
2. Grading & cleanliness
Sieve analysis gives the particle size distribution. The sand equivalent test shows how much clay-like fines the sand carries.
3. Strength, durability & friction
Abrasion tests show how aggregate breaks down under impact and wear. Point load testing indexes rock strength. Pendulum testing measures skid resistance.
- Sample preparation
- Grading & fines
- Strength & abrasion
- Skid resistance
- Comparison table
- How to choose
- FAQ
Step 1
Sample preparation equipment
Every aggregate test starts with a sample that represents the stockpile, quarry face or core run. These two instruments reduce the size of the material and the size of the sample without changing its character.
Jaw Crusher
A laboratory jaw crusher breaks rock lumps, drill core and oversize aggregate between a fixed and a moving jaw. The gap between the jaws sets the maximum size of the crushed product, so one machine can produce material for several tests: a graded fraction for abrasion testing, crushed stone for a trial grading, or smaller pieces for further pulverising before chemical analysis.
- Used for: crushing rock, core and oversize aggregate before testing
- Output size: set by the adjustable jaw gap
- Feed opening, capacity & power supply: ask Ecotao for the current model datasheet
Best for: quarries, mines, geotechnical labs and borrow-pit investigations that receive rock rather than ready-graded aggregate.
Riffle Sampler (Stainless Steel)
A riffle sampler, also called a riffle box or sample splitter, divides a dry sample into two equal halves. Material poured across the top falls through a row of equal-width chutes that discharge alternately to the left and right pans, so both halves keep the same grading. Repeating the split brings a large field sample down to the mass a test calls for, without the bias that comes from scooping or coning by hand. Stainless steel resists corrosion and is easy to clean between samples.
- Method: mechanical splitting of aggregate samples, as described in ASTM C702 (reducing samples of aggregate to testing size)
- Material: stainless steel
- Chute width: must suit the largest particle in the sample; ask Ecotao to match the riffle to your aggregate size
Best for: any lab that receives bulk aggregate, sand or crushed rock samples and needs repeatable test portions.
Step 2
Grading and fines content
Particle size distribution is the most frequently run aggregate test. It decides whether a material meets a grading envelope for concrete, asphalt or road base. The sand equivalent test checks the fine fraction for clay that sieving alone does not reveal.
Grid Sieves
Test sieves separate an aggregate sample into size fractions. The sample is passed through a stack of sieves with progressively smaller apertures, and the mass retained on each sieve gives the grading curve. Coarse aggregate needs large-aperture sieves and larger frames to avoid overloading, while fine aggregate is graded down to the 75 micron sieve to measure the fines content.
- Test: particle size analysis by sieving, SANS 3001-AG1 in South Africa
- Apertures & frame diameters: ask Ecotao for the sizes your grading specification calls for
- Individual 20 cm sieves: available from the Ecotao online store
Best for: grading concrete sand and stone, asphalt aggregate, road base and ballast.
Digital Sieve Shaker
A motorised sieve shaker moves a full stack of test sieves for a set time, so every sample is sieved with the same motion and duration. Hand sieving varies from operator to operator; a shaker with a digital timer removes that variable and frees the technician while the stack runs. The result is a more repeatable grading curve and higher sample throughput.
- Control: digital display with a set sieving time
- Used with: a stack of test sieves, lid and receiver pan
- Sieve diameter & maximum sieves per stack: ask Ecotao
Best for: labs running routine gradings every day, where repeatability between operators matters.
High Frequency Sieve Shaker
A high frequency sieve shaker drives the sieve stack with a rapid vibratory motion instead of a slower orbital or tapping action. The fast, short movement keeps fine particles bouncing on the mesh so they find the openings, which helps with crusher dust, filler and fine sand that tend to blind sieves and give a falsely coarse result.
- Motion: high-frequency vibration
- Suited to: fine aggregate, crusher dust and filler fractions
- Sieve diameter, amplitude range & stack capacity: ask Ecotao
Best for: fine aggregate and filler grading, and labs that also sieve soils and powders.
Electric Sand Equivalent Shaker (Single Tube)
The sand equivalent test shows how much clay-like fines a sand carries. Fine aggregate is shaken in a graduated plastic cylinder with a flocculating solution, then left to settle. The clay forms a suspension above the sand, and the ratio of the sand reading to the clay reading is the sand equivalent value. A motorised shaker gives every cylinder the same shaking, which hand shaking cannot match. This model shakes one cylinder at a time.
- Test: sand equivalent value of fine aggregate (SANS 3001-AG5, ASTM D2419, AASHTO T176)
- ASTM D2419 mechanical shaking: 203 mm stroke at 175 cycles per minute for 45 seconds
- Capacity: single cylinder
Best for: acceptance testing of concrete sand, asphalt fines and road base fines.
Step 3
Rock strength and abrasion resistance
Aggregate in a road or a railway is crushed by loads and worn by traffic, often while wet. These three machines measure how a rock or aggregate resists breaking and wearing down.
Digital Display Point Load Tester
A point load tester is a compact loading frame that squeezes a rock specimen between two conical platens until it splits. It works on drill core (diametral and axial tests), sawn blocks and irregular lumps, so specimens can be tested on site with little preparation. The digital display shows the failure load, which is converted to the point load strength index Is(50). Because the test is quick and portable, it is used to log rock strength along a core run and to estimate uniaxial compressive strength (UCS) without a full compression test.
- Test: point load strength index of rock, ASTM D5731
- Platens (per ASTM D5731): 60° cone with a 5 mm radius spherical tip
- Result: Is(50), the index corrected to a 50 mm diameter; UCS estimated as C × Is(50)
- Load capacity & maximum specimen size: ask Ecotao
Best for: geotechnical drilling, mining, quarry face assessment and tunnelling, where many rock samples need a fast strength index.
Los Angeles Splitter Abrasion Testing Machine
The Los Angeles (LA) abrasion machine is a closed steel drum with an internal shelf, loaded with a graded aggregate sample and a charge of steel spheres. As the drum turns, the shelf lifts the sample and spheres and drops them, so the aggregate is broken by impact as well as worn by abrasion. After the set number of revolutions the sample is sieved and the mass lost is reported as a percentage. A high LA value indicates aggregate that will break down under compaction and traffic.
- Tests: ASTM C131 (aggregate under 37.5 mm), ASTM C535 (larger coarse aggregate), EN 1097-2
- ASTM C131 drum: 711 mm inside diameter × 508 mm inside length, turning at 30 to 33 rpm for 500 revolutions
- ASTM C131 charge: 6 to 12 steel spheres of about 46.8 mm, depending on grading
- Result: percentage loss (ASTM C131: material passing the 1.70 mm sieve)
- Revolution counter, drive & standards built to: ask Ecotao
Best for: quarries and road, railway ballast and concrete aggregate suppliers working to ASTM or EN specifications.
Micro-Deval Abrasion Machine
The Micro-Deval machine rotates steel jars containing coarse aggregate, water and small steel balls. The test measures how much the aggregate wears when wet, which picks up weak, absorptive or soft particles that a dry test can miss. Because the motion is a tumbling abrasion rather than heavy impact, the result reflects how aggregate degrades in a moist pavement layer or during stockpiling and handling.
- Tests: ASTM D6928, AASHTO T327, EN 1097-1
- ASTM D6928 charge: up to 5000 g of 9.5 mm steel balls with water
- ASTM D6928 run: 100 rpm for 2 hours, in a jar of about 5 litres
- Number of jars & control options: ask Ecotao
Best for: road base and asphalt aggregate acceptance, especially where aggregate stays damp in service.
Step 4
Skid resistance and polished stone value
A road surface is only as safe as its grip. Traffic polishes surfacing aggregate over time, so skid resistance is tested both on the finished surface and on the aggregate before it is laid.
Friction Coefficient Meter (Pendulum Type)
The pendulum friction tester, often called the British pendulum or skid resistance tester, releases a weighted arm with a rubber slider at its foot. The slider sweeps across a wetted surface, and the height the arm reaches on the far side shows how much energy friction absorbed. It is portable and can be used on roads, runways, footpaths and floors. In the lab, the same instrument with a narrower slider tests curved aggregate specimens after accelerated polishing to give the polished stone value (PSV).
- Tests: ASTM E303 and EN 13036-4 (surface friction), EN 1097-8 (polished stone value), AASHTO T278
- Measures: skid resistance of road surfaces, floors and polished aggregate specimens
- Sliders, scales & calibration: ask Ecotao which slider sets are supplied
Best for: road authorities, surfacing contractors, airports and flooring or slip-risk assessments.
Specs on this page: figures quoted under a standard's name (drum size, stroke, ball charge, platen shape) are the test method's requirements, not a promise about a particular machine. Ask Ecotao for the datasheet of the model on offer to confirm which standards it is built to.
Workflow
How the equipment fits together in an aggregate lab
- Crush
Reduce rock or core with the jaw crusher. - Split
Reduce the sample to test mass with the riffle sampler. - Grade
Sieve through grid sieves on a digital or high frequency shaker. - Check fines
Run the sand equivalent test on the fine fraction. - Test performance
LA abrasion, Micro-Deval, point load or pendulum, as the specification requires.
Comparison
Rock and aggregate tests compared
What each instrument measures, the test methods it relates to, and the result it produces.
← Scroll to see full table →
| Equipment | What it measures | Material tested | Test methods | Result |
|---|---|---|---|---|
| Jaw Crusher | Sample preparation (size reduction) | Rock, core, oversize aggregate | Preparation step for other tests | Crushed material for testing |
| Riffle Sampler | Sample preparation (splitting) | Dry aggregate and sand | ASTM C702 | Representative test portion |
| Grid Sieves | Particle size distribution | Fine and coarse aggregate | SANS 3001-AG1 | Grading curve, % passing each sieve |
| Digital Sieve Shaker | Particle size distribution (timed) | Aggregate and soil | Used with sieve analysis methods | Repeatable grading |
| High Frequency Sieve Shaker | Particle size distribution (vibratory) | Fine aggregate, dust, filler | Used with sieve analysis methods | Repeatable grading of fines |
| Sand Equivalent Shaker | Clay-like fines in sand | Fine aggregate | SANS 3001-AG5, ASTM D2419, AASHTO T176 | Sand equivalent value |
| Point Load Tester | Rock strength index | Core, blocks, irregular lumps | ASTM D5731 | Is(50); estimated UCS |
| Los Angeles Abrasion Machine | Dry impact and abrasion loss | Coarse aggregate | ASTM C131, ASTM C535, EN 1097-2 | % loss / LA coefficient |
| Micro-Deval Machine | Wet abrasion loss | Coarse aggregate | ASTM D6928, AASHTO T327, EN 1097-1 | % loss / Micro-Deval coefficient |
| Pendulum Friction Tester | Skid resistance | Road and floor surfaces, polished aggregate | ASTM E303, EN 13036-4, EN 1097-8, AASHTO T278 | Pendulum value; PSV |
Selection guide
How to choose rock and aggregate testing equipment
1. Start from the specification
List every test your projects call for and the standard each one cites. A South African road authority specification will usually cite SANS 3001 methods; an international or mining contract may cite ASTM or EN. Buy the equipment that matches the cited method, because the drum size, charge, stroke or platen shape is defined by the standard.
2. Match sieves and shakers to your largest and finest material
Coarse aggregate and ballast need large apertures and larger frames so the sieves are not overloaded. Fine sand, crusher dust and filler sieve better on a high frequency vibratory shaker. Count how many sieves your grading envelope needs in one stack and confirm the shaker takes that many.
3. Decide where the testing happens
The point load tester and pendulum friction tester are portable and work on site or at the core shed. Los Angeles and Micro-Deval machines, sieve shakers and the jaw crusher are bench or floor equipment that need a lab with power supply and space for noise and dust.
4. Plan for throughput
A lab running many gradings a day benefits from a timed digital shaker and more than one sieve set. A single-tube sand equivalent shaker suits moderate volumes; ask Ecotao if you need to test several cylinders at once.
5. Don't skip sample preparation
A riffle sampler costs far less than a strength test machine, but a biased sample invalidates every result after it. Choose a riffle whose chute width suits your largest particle size.
South Africa
Aggregate testing in South Africa: SANS 3001 methods
South African road and civil engineering laboratories test aggregates to the SANS 3001 series, which replaced the older TMH1 methods. Several instruments on this page are used directly in that series:
- SANS 3001-AG1: particle size analysis of aggregates by sieving (grid sieves and sieve shakers)
- SANS 3001-AG4: flakiness index of coarse aggregate (graded fractions from the same sieve set)
- SANS 3001-AG5: sand equivalent value of fine aggregate (sand equivalent shaker)
The Los Angeles, Micro-Deval, point load and pendulum tests are ASTM, EN or AASHTO methods. They are used in South Africa where a project, mine or client specification calls for them, and for polished stone value testing of surfacing aggregate.
Ecotao supplies laboratories, contractors, quarries and consulting engineers from Cape Town, with delivery throughout South Africa, Namibia, Botswana, Zimbabwe, Mozambique, Lesotho and Eswatini.
FAQ
Frequently asked questions
What equipment do I need to set up an aggregate testing laboratory?
Most aggregate labs start with sample preparation and grading: a riffle sampler to reduce samples, a set of test sieves with a sieve shaker for grading, and a sand equivalent shaker for fine aggregate cleanliness. A jaw crusher is added when rock or core has to be reduced. Strength and durability tests, such as Los Angeles abrasion, Micro-Deval and point load, are added according to the specifications your projects are tested against.
What is the difference between the Los Angeles abrasion test and the Micro-Deval test?
The Los Angeles test is dry. Large steel spheres and a shelf inside a rotating drum combine impact and abrasion, and the result is the percentage of material lost through a 1.70 mm sieve under ASTM C131. The Micro-Deval test is wet. Coarse aggregate is tumbled in a jar with water and 9.5 mm steel balls, which measures abrasion and weakening when wet, without heavy impact. Many specifications ask for both because they detect different weaknesses.
How is the point load strength index related to UCS?
ASTM D5731 estimates uniaxial compressive strength as a factor C multiplied by the point load strength index Is(50). The standard gives generalised C values that rise with core size, for example 23 for a 50 mm core, but recommends correlating C for the specific rock type when an accurate UCS estimate matters.
What does the sand equivalent test measure?
The sand equivalent test measures the relative proportion of clay-like or plastic fines to sand in fine aggregate. The sample is shaken in a graduated cylinder with flocculating solution, left to settle, and the sand reading is compared with the clay reading. Low values indicate dirty sand that can weaken asphalt, concrete or base layers. In South Africa the method is SANS 3001-AG5; ASTM D2419 and AASHTO T176 are the US equivalents.
Do I need a digital sieve shaker or a high frequency sieve shaker?
A digital sieve shaker suits routine grading of a stack of sieves with a set, repeatable sieving time. A high frequency vibratory shaker is usually chosen for fine fractions and dusty material that tends to blind the mesh. Labs grading both coarse aggregate and fines often use one of each. Ecotao can confirm which sieve diameters and how many sieves each model takes.
What does a pendulum friction tester measure?
A pendulum friction tester measures skid resistance. A rubber slider on a pendulum arm sweeps across a wetted surface and the energy lost to friction is read off a scale. It is used on road surfaces and floors (ASTM E303, EN 13036-4) and, with a narrow slider and curved polished specimens, for the polished stone value of road aggregate (EN 1097-8).
Why reduce an aggregate sample with a riffle sampler instead of scooping?
Scooping tends to pick up a biased share of fines or coarse particles, so the test portion no longer represents the stockpile. A riffle sampler splits the sample through equal-width chutes that discharge alternately to each side, giving two halves with the same grading. Repeating the split reduces the sample to test size, as described in ASTM C702. The chute width must suit the largest particle in the sample.
Does Ecotao deliver rock and aggregate testing equipment outside Cape Town?
Yes. Ecotao is based in Cape Town and supplies equipment throughout South Africa and to Namibia, Botswana, Zimbabwe, Mozambique, Lesotho and Eswatini. Contact sales@ecotao.co.za or +27 21 911 5835 for a quote and delivery lead time.
Equipping an aggregate or rock testing lab?
Tell us which tests and standards you work to, and we'll quote the matching equipment with datasheets and delivery lead times.
- Head Office: +27 21 911 5835
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- Email: sales@ecotao.co.za · aqua@ecotao.co.za