DWT Hamburg Type Double Wheel Tracker

DWT Hamburg Type Double Wheel Tracker

The Hamburg Type Double Wheel Tracker for Hot Mix Asphalt (HMA) is a testing device used to evaluate the rutting resistance and moisture susceptibility of asphalt pavement.

The wheel tracker is equipped with sensors to measure the rut depth and moisture-induced distress of the asphalt samples under controlled conditions. This testing helps assess the performance and durability of asphalt mixes, aiding in the design and optimization of pavement materials for long-lasting and safe road infrastructure.

It consists of a heavy-duty wheel that applies a controlled load and simulates the repeated traffic loads experienced by the pavement at a fixed temperature.

Two versions are available with full access to the water bath or complete with clear transparent sliding doors, water bath covers and automatic water filling and levelling system.

Machine body

Sheet steel, powder coated. Transparent 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 molds 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 deformations from 0 to 50 mm ±0.01 mm.

Features

• 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
• 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 360×300 mm (for 320×260 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

Models

78-PV31A16

DWT Hamburg Type double wheel tracker. Conforming to AASHTO T324, water specimen conditioning. Complete with laptop PC and software. 220V/60Hz/3Ph

78-PV31A26

DWT, Hamburg Type, double wheel tracker, conforming to AASHTO T324, water specimen conditioning. Complete with laptop PC, software and transparent sliding door. 220V/60Hz/3Ph+N