Motorized Laboratory Bitumen Ductilometer
Stainless steel water bath trough (1.5 m length) with variable speed leadscrew pulling carriage and digital distance encoder.
Civil Engineering / Bitumen Ductility Test
FREE TO EXPLORELABORATORY 42 · CIVIL ENGINEERING
Tensile Ductility and Elongation of Bituminous Asphalt Binders in a Temperature-Controlled Water Bath
Measure tensile elongation distance before rupture of a briquette specimen of bituminous binder pulled at a constant speed of 50 mm/min at 25°C in a water bath according to ASTM D113 / AASHTO T51. Explore interactive structural mechanics, materials simulation, and civil engineering telemetry.
STRUCTURAL MATERIALS · MECHANICS · GEOTECHNICAL · HYDRAULICS · HIGHWAYS · SURVEYING
Your virtual civil engineering laboratory.
ELONGATED THREAD LENGTH L—
CIVIL INFRASTRUCTURE TELEMETRY
Ready to sample with Pulling Time t = 19.0 min.
Adjust Pulling Time t, 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 (10.0 to 25.0 min). Tested on paving-grade bitumen (Grade 60/70) at standard pulling speed 50.0 mm/min (5.0 cm/min) at 25.0 °C. Linear kinematic model relates elongated thread length L directly to elapsed time t with rate constant 5.0000 cm/min.
Laboratory apparatus & testing equipment.
Standard Brass Briquette Molds
Four-piece machined brass molds with hourglass central neck (10.0 mm × 10.0 mm cross section) conforming to ASTM D113.
Thermostatic Water Bath Heating & Chilling Unit
Circulating refrigeration and heating system maintaining bath at 25.0 ± 0.5 °C (or 4.0 ± 0.5 °C for low-temp tests).
Submerged Briquette Support Plate
Perforated shelf holding specimens at least 25 mm above trough bottom and 25 mm below water surface.
Specific Gravity Bath Fluid Adjuster (NaCl / Alcohol)
Adjusts bath liquid density to match bitumen (1.01 to 1.04 g/cm³) so the stretching thread neither floats nor sinks.
Straight Trimming Putty Knife
Hot-blade knife for trimming excess asphalt flush with mold top.
FOLLOW THE METHOD
A reason behind every step.
Measure tensile elongation distance before rupture of a briquette specimen of bituminous binder pulled at a constant speed of 50 mm/min at 25°C in a water bath according to ASTM D113 / AASHTO T51. Standardized parameter settings: 10.0, 13.0, 16.0, 19.0, 22.0, 25.0 min.
01
Mold Assembly & Amalgam Release Coating
Assemble brass briquette mold pieces on a brass baseplate; coat mold contact surfaces with a thin film of glycerin-dextrin release agent to prevent adhesion.
02
Bitumen Melting & Briquette Casting
Heat bitumen sample to 140 °C; stir gently; pour molten binder into molds until overflowing; allow to cool undisturbed in air for 40 minutes.
03
Mold Trimming & Water Bath Equilibration
Trim excess bitumen level with top of mold using a warmed straightedge knife; place molds in ductilometer water bath at 25.0 ± 0.5 °C for exactly 90 minutes.
04
Mounting Molds onto Ductilometer Carriage
Remove side pieces of molds carefully without disturbing the bitumen briquette neck; attach end clips to pins on the fixed and motorized carriage in the water bath.
05
Motorized Pulling at 50 mm/min
Engage leadscrew motor at standard pulling rate of 50.0 ± 2.5 mm/min (5.0 cm/min); observe stretching of the central bitumen neck into a thin thread.
06
Thread Elongation Tracking & Rupture Logging
Track elongation distance L across time intervals (10, 13, 16, 19, 22, and 25 min); verify thread remains suspended neutrally without touching tank floor or surface; record rupture distance in cm.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into civil engineering insight.
Points are your recorded observations. The solid regression line validates Bitumen Ductility Test mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
Ductility = 5.0000 · t
| # | Traction Test Duration t (min) | Elongated Thread Length L (cm) | Traction pulling time t (minutes) | Elongated ductile bitumen thread length L (cm) | Remove |
|---|
No readings yet. Execute a civil engineering trial and record it.
Calculate it yourself.
CHECK YOUR UNDERSTANDING
Explain what the civil engineering metrics mean.
The standardized pulling speed for the ASTM D113 Bitumen Ductility test is:
The initial minimum cross-sectional area of the standard bitumen briquette neck is:
For premium paving-grade bitumen (Grade 60/70), the minimum specified ductility at 25 °C is:
If the stretching bitumen thread sinks and touches the bottom of the water bath trough, the test is:
THEORY AND STRUCTURAL CONTEXT
Civil engineering background & physical principles.
In flexible highway pavement engineering, bituminous binders must possess sufficient tensile ductility and cohesive flexibility to stretch and relax under repetitive heavy vehicular traffic deflections and diurnal thermal contraction cycles without premature micro-cracking. Bituminous binders that lack ductility or have undergone severe oxidative aging become brittle, leading to rapid block cracking, thermal fatigue cracking, and stone raveling. Standardized under ASTM D113 / AASHTO T51, the Bitumen Ductility Test measures the tensile elongation in centimeters that a briquette specimen of asphalt binder can endure before snapping. Molten bitumen is poured into a standardized brass briquette mold having an hourglass neck profile (minimum cross section of exactly 10.0 mm width by 10.0 mm height, area 1.0 cm²). After ambient cooling and trimming, the briquette mold clips are attached to the pulling carriage of a motorized ductilometer submerged in a large temperature-controlled water bath maintained at 25.0 ± 0.5 °C. The drive carriage pulls the briquette halves apart horizontally at a uniform, pulsation-free speed of 50.0 ± 2.5 mm/min (5.0 cm/min). The bitumen specimen stretches into an increasingly fine, micro-thin thread; the distance in centimeters at which the thread ruptures is recorded as the Ductility Value. Pavement specifications strictly mandate Ductility ≥ 100 cm at 25 °C for virgin paving bitumens (Grade 60/70 and 80/100). In this laboratory experiment, thread elongation is tracked across traction intervals from 10.0 to 25.0 minutes to calibrate elongation rate slope = 5.0000 cm/min and verify compliance (Ductility > 100 cm).
Ductility = 5.0000 · t
Tested on paving-grade bitumen (Grade 60/70) at standard pulling speed 50.0 mm/min (5.0 cm/min) at 25.0 °C. Linear kinematic model relates elongated thread length L directly to elapsed time t with rate constant 5.0000 cm/min.