Description

The wheel tracking test is used for determining the susceptibility of Hot Mix Asphalt (HMA) to deform under load by measuring the rut depth formed by repeated passes of a loaded wheel at a fixed temperature.  We also produce  Wheel Trackers conforming to EN 12697-22 standard and a Universal version conforming to both AASHTO and EN Standards. See Double Wheel Tracker, EN versions and Universal AASHTO/EN Double Wheel Tracker.
Two versions are available with full access to the water bath or complete with clear trasparent sliding doors, water bath covers and automatic water filling and leveling system.

The DWT Hamburger type Double Wheel Tracker can be used as part of your Superpave performance based testing program.

Machine body
Sheet steel, powder coated. Trasparent sliding door.

Loaded wheel system
The wheel load is 705 N. The system includes a motorized lifting system for raising the wheel assembly at the end of the test.

Wheel tracking carriage
The wheel is moved 230 mm backwards and forwards on the top of the slab, which is fixed. The speed is adjustable via the PC from 20 to 30 cycles per minute (40 to 60 passes). The longest slab dimension is oriented to the wheel's direction of travel. Special slab moulds for circular samples obtained from coring or gyratory compactors are also available. See accessories.

Temperature control system
The AASHTO Hamburg type Standard states that the test must be performed in a water bath with a temperature range of 258 to 70° ±1°C. A water level of about 20 mm above the sample has to be maintained. Where a heated air environment is specified, the specimen, during testing, must be maintained at uniform and constant specified temperature ± 1°C. The DWT Double Wheel Trackers fully satisfy and exceed the above requirements: the temperature accuracy is ± 0.5°C.

Impression measurement system
Each wheel is fitted with RUT DEPTH transducers for measuring deformationsfrom 0 to 40 mm ±0.01 mm.

• Full conformity to AASHTO T324-19, including sinusoidal movement (RMSE certificate available on request) and rut depth measurement in 11 defined points
• Full conformity to TxDOT TEX-242-F specifications
• Fully automatic test performance on two specimens or one specimen
• Variable wheel speed from 20 to 30 cycles/min
• Fixed table, mobile wheel 230 mm travel
• Wheel load of 705 N
• Temperature range from ambient to 80°C (±0.5°C)
• Accurate temperature control (±0.5°C) for both in water test
• Rut depth transducers feature 50 mm travel, 0.01 mm accuracy
• Direct rut depth measurement system, with transducers axially mounted in alignment with the wheel's centre
• Motorized wheel-assembly lifting system for easy removal of slabs
• Free access to the wide testing area
• Optional independent lifting system for double or single wheel testing
• Slab mould size of 360x300 mm (for 320x260 mm slabs), double 150 mm gyratory compactor cylinders, 200 mm/8"/10" diameter cores
• Slab thickness adjustable from 40 to 100 mm (in 10 mm steps)
• Extensive use of stainless steel in the machine's construction; not limited to the parts in contact with water
• Automatic water filling and leveling system, no need to adjust or control the water level above the specimen during test
• Possibility to add two optional temperature probes to monitor the two samples temperature
• Laptop PC control with dedicated software including results performance, test database management and multiple test elaboration
• The software includes the possibility to program pre-heating and machine start (without operator intervention) and to measure the rut depth measurement in user-defined positions for research purposes or local specifications