Standard Los Angeles Abrasion Testing Machine
Heavy-gauge rolled steel drum (711 mm internal diameter, 508 mm length) with dust-tight cover and digital revolution counter.
Civil Engineering / Los Angeles Abrasion
FREE TO EXPLORELABORATORY 37 · CIVIL ENGINEERING
Resistance to Degradation of Coarse Aggregates by Abrasion & Impact (Los Angeles Machine)
Determine the Los Angeles (LA) Abrasion Value of coarse mineral aggregates subjected to combined mechanical impact, crushing, and abrasive grinding in the rotating steel drum according to ASTM C131 / AASHTO T96. Explore interactive structural mechanics, materials simulation, and civil engineering telemetry.
STRUCTURAL MATERIALS · MECHANICS · GEOTECHNICAL · HYDRAULICS · HIGHWAYS · SURVEYING
Your virtual civil engineering laboratory.
DEGRADED FINES MASS PASSING 1.70 MM SIEVE—
CIVIL INFRASTRUCTURE TELEMETRY
Ready to sample with Revolutions N = 300.0 revs.
Adjust Revolutions N, then execute civil engineering measurement.
Civil engineering telemetry is evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity structural mechanics and geotechnical continuum modeling.
Civil engineering assumptions and boundary condition limits
The civil engineering physical models apply within the specified calibrated operational window (100.0 to 500.0 revs). Tested on crushed basalt highway coarse aggregate (Grading B, initial mass M = 5000.0 g, 11 steel abrasive spheres). Linear degradation model relates fines mass to drum revolutions with slope 2.4500 g/rev.
Laboratory apparatus & testing equipment.
Abrasive Steel Spheres Charge
11 precision cast-iron/steel spheres (46.8 mm diameter, combined mass 4584 ± 25 g) conforming to ASTM C131.
Standard Nested Sieves (12.5 mm, 9.5 mm, and 1.70 mm / No. 12)
Brass frame sieves separating initial grading and isolating degraded mineral fines.
Thermostatic Electric Drying Oven
Maintains 110 ± 5 °C for oven drying aggregate specimens before and after washing.
High-Capacity Heavy-Duty Digital Platform Scale
Measures 5000 g bulk aggregate charges to 0.5 g accuracy.
Mechanical Sieve Shaker & Washing Pan
Facilitates 10-minute mechanical sieving and water-washing of sieve residue.
FOLLOW THE METHOD
A reason behind every step.
Determine the Los Angeles (LA) Abrasion Value of coarse mineral aggregates subjected to combined mechanical impact, crushing, and abrasive grinding in the rotating steel drum according to ASTM C131 / AASHTO T96. Standardized parameter settings: 100.0, 180.0, 260.0, 340.0, 420.0, 500.0 revs.
01
Aggregate Washing, Sizing & Oven Drying
Wash crushed basalt aggregate to remove dust; sieve into Grading B fractions (2500 g passing 19.0 mm / retained 12.5 mm, and 2500 g passing 12.5 mm / retained 9.5 mm); oven dry at 110 °C for 16 hours to constant mass M_initial = 5000.0 g.
02
Drum Charging & Steel Sphere Loading
Clean interior of LA machine drum; inspect shelf for wear; place 5000.0 g aggregate charge and exactly 11 steel abrasive spheres into drum; seal dust-tight cover plate.
03
Automated Rotation at Controlled Speed
Set digital counter to target revolutions (100, 180, 260, 340, 420, and 500 revs); run machine at 31 rpm; observe sound of abrasive ball impacts.
04
Sample Discharge & Coarse Separation
Open drum cover; discharge entire mixture into catching pan; separate steel abrasive spheres using magnet; inspect aggregate breakdown.
05
Sieving Over 1.70 mm (No. 12) Sieve
Pass pulverized aggregate over 1.70 mm sieve; wash retained material over the sieve with running tap water until wash water runs clear.
06
Oven Drying Retained Coarse Fraction & Loss Calculation
Oven dry washed aggregate retained on 1.70 mm sieve at 110 °C; weigh dry retained mass M_retained; compute degraded fines mass M_fines = M_initial - M_retained; calculate LA Abrasion Loss percentage.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into civil engineering insight.
Points are your recorded observations. The solid regression line validates Los Angeles Abrasion mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
Fines = 2.4500 · N
| # | Drum Revolution Cycles N (revs) | Degraded Fines Mass Passing 1.70 mm Sieve (g) | Drum revolution cycles N (revolutions) | Degraded mineral fines mass passing 1.70 mm sieve (g) | Remove |
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No readings yet. Execute a civil engineering trial and record it.
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CHECK YOUR UNDERSTANDING
Explain what the civil engineering metrics mean.
The standardized rotation speed of the Los Angeles Abrasion drum is:
The sieve used to separate degraded fines from intact coarse aggregate in the LA Abrasion test is:
For premium open-graded friction course (OGFC) asphalt surface mixtures, maximum allowable LA Abrasion loss is typically:
The internal shelf inside the LA Abrasion drum serves to:
THEORY AND STRUCTURAL CONTEXT
Civil engineering background & physical principles.
In civil highway and pavement engineering, coarse mineral aggregates comprise 90% to 95% of the total mass of asphalt concrete mixtures and up to 80% of Portland cement concrete pavements. During pavement construction (stockpiling, pneumatic mixing, vibratory roller compaction) and throughout service life under heavy pneumatic commercial truck wheel traffic, coarse aggregates are subjected to intense mechanical crushing, edge grinding, and impact degradation. Standardized under ASTM C131 / AASHTO T96, the Los Angeles (LA) Abrasion Test evaluates aggregate mechanical toughness and abrasion resistance. A clean, oven-dried 5000 g aggregate sample of specified gradation (Grading A, B, C, or D) is charged into a hollow steel drum (711 mm internal diameter, 508 mm length) along with an abrasive charge of 6 to 12 cast-iron or steel spheres (approx. 46.8 mm diameter, 390 to 445 g each). As the drum rotates at 30 to 33 rpm, an internal radial shelf catches the aggregates and steel spheres, carrying them upward until they drop 700 mm onto the opposite drum wall, inflicting severe impact crushing combined with mutual abrasive friction. After 500 complete revolutions, the aggregate charge is removed, dry-sieved over a 1.70 mm (No. 12) sieve, and washed to determine the loss percentage: LA Loss (%) = [(M_initial - M_retained) / M_initial] · 100. Highway agency specifications restrict LA loss to ≤ 25% for high-speed wearing courses and ≤ 40% for base courses. In this laboratory experiment, degraded fines mass is monitored across revolution increments from 100 to 500 revs to calibrate degradation rate slope = 2.4500 g/rev (LA loss = 24.5%).
Fines = 2.4500 · N
Tested on crushed basalt highway coarse aggregate (Grading B, initial mass M = 5000.0 g, 11 steel abrasive spheres). Linear degradation model relates fines mass to drum revolutions with slope 2.4500 g/rev.