Standard Aggregate Impact Testing Machine
Rigid steel frame with 13.5 to 14.0 kg sliding drop hammer, 380 mm free drop guide rods, and cast-iron anvil (> 22 kg).
Evaluate aggregate mechanical toughness against dynamic shock impact (BS 812-112) and resistance to crushing under progressive static compressive loading (BS 812-110 / IS 2386-4). Explore interactive structural mechanics, materials simulation, and civil engineering telemetry.
Ready to sample with Impact Blows N = 14.0 blows.
Adjust Impact Blows 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.
The civil engineering physical models apply within the specified calibrated operational window (5.0 to 20.0 blows). Tested on hard quartzite roadstone aggregate (12.5 mm to 10.0 mm fraction, initial mass M = 350.0 g). Linearized impact model correlates fines percentage (< 2.36 mm) to blow count N with slope 1.6500 %/blow.
Rigid steel frame with 13.5 to 14.0 kg sliding drop hammer, 380 mm free drop guide rods, and cast-iron anvil (> 22 kg).
Machined steel test cup (102 mm diameter, 50 mm depth) clamped securely to the machine base.
10 mm diameter, 230 mm long round steel rod with rounded bullet end for sample consolidation.
Brass frame sieves for fraction preparation and post-impact fines separation.
Measures specimen fractions to 0.1 g accuracy (capacity 2000 g).
Dries aggregate fractions at 105 to 110 °C for 4 hours to eliminate moisture cushioning.
Evaluate aggregate mechanical toughness against dynamic shock impact (BS 812-112) and resistance to crushing under progressive static compressive loading (BS 812-110 / IS 2386-4). Standardized parameter settings: 5.0, 8.0, 11.0, 14.0, 17.0, 20.0 blows.
Sieve bulk aggregate to extract particles passing the 12.5 mm sieve and retained on the 10.0 mm sieve; dry in oven at 110 °C for 4 hours; cool to room temperature.
Fill cylindrical steel measure in three equal layers; tamp each layer with 25 strokes of bullet-nosed tamping rod; strike off surplus with straightedge; record initial mass M_initial (approx. 350 g).
Transfer sample into the machine cup; ensure uniform bed thickness; tamp with 25 strokes; clamp cup firmly onto the heavy cast-iron anvil base.
Adjust hammer free-fall height to exactly 380 ± 5 mm above aggregate surface; release hammer across target blow counts (5, 8, 11, 14, 17, and 20 blows) at 1-second intervals.
Carefully remove pulverized aggregate from cup into pan; sieve over 2.36 mm sieve for 5 minutes; brush cup interior clean into pan.
Weigh fraction passing 2.36 mm sieve (M_fines) and retained fraction (M_retained); verify total mass within 1.0 g of M_initial; calculate AIV (%) = (M_fines / M_initial) · 100.
Points are your recorded observations. The solid regression line validates Aggregate Impact & Crushing mathematical scaling.
| # | Standard Mechanical Impact Blows N (blows) | Generated Fines Percentage (< 2.36 mm) (%) | Mechanical impact blow count N (blows) | Generated mineral fines percentage passing 2.36 mm (%) | Remove |
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In highway pavement design, bridge deck overlays, and railway ballast engineering, mineral aggregates must resist dynamic shock impacts from high-speed vehicular traffic and wheel flat spots without shattering into structural powder. The Aggregate Impact Value (AIV) test (BS 812-112 / IS 2386-4) directly quantifies aggregate dynamic toughness. A standardized cylindrical steel measure (102 mm internal diameter, 50 mm depth) is filled with oven-dried aggregate passing the 12.5 mm sieve and retained on the 10.0 mm sieve, consolidated in three layers with 25 tamping rod strokes. The sample is transferred into a heavy cast-iron cup secured to a rigid anvil resting on a concrete floor. A 13.5 to 14.0 kg sliding steel hammer drops freely from a height of 380 ± 5 mm down vertical guide rails onto the aggregate bed. Under standard testing, exactly 15 blows delivered at an interval of not less than one second subject the aggregate particles to intense compressive shock waves. The crushed specimen is removed and sieved over a 2.36 mm (BS No. 8) sieve: AIV (%) = (M_fines / M_initial) · 100. Pavement specifications classify aggregates based on AIV: < 10% exceptionally tough, 10% to 20% strong for high-speed wearing courses, 20% to 30% acceptable for road base courses, and > 35% weak and unfit for pavement construction. In this laboratory investigation, fines generation is evaluated across 5 to 20 impact blows to calibrate dynamic crushing sensitivity slope = 1.6500 %/blow (yielding standard 15-blow AIV = 24.75%).
Tested on hard quartzite roadstone aggregate (12.5 mm to 10.0 mm fraction, initial mass M = 350.0 g). Linearized impact model correlates fines percentage (< 2.36 mm) to blow count N with slope 1.6500 %/blow.