Controls Group http://www.controls-group.com/images/logo_controls.gif DWT Universal AASHTO/EN Double Wheel Tracker DWT Universal AASHTO/EN Double Wheel Tracker
close
Asphalt/bituminous mixture

DWT Universal AASHTO/EN Double Wheel Tracker

The DWT UNIVERSAL Double Wheel Tracker performing both AASHTO Hamburg Type and EN tests, with unique solutions for the maximum accuracy and reliability

EN 12697-22 | AASHTO T324
Main features
  • Meets and exceed AASHTO and EN standards and many DOT method
  • 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 700/705 N or adjustable from 700 to 1500 N
  • Temperature range from ambient to 80°C (±0.5°C)
  • Accurate temperature control (±0.5°C) for both in water and air test
  • Ruth depth transducers feature 25 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 400x300 mm, 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
  • PC and software included
  • Automatic water filling and leveling system, no need to adjust or control the water level above the specimen during test
  • Laptop PC control with dedicated software including results performance, test database management and multiple test elaboration
General description
General 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. 

This universal version complies either to AASHTO or EN standards being equipped with both stainless steel and rubber wheels, and performing the test in air or water. This solution is particularly suitable for research laboratories.
This  version can be upgraded with automatic system which lift one of the wheel from the specimen that has reached the rut target continuing the test on the other specimen. See Upgrading options Automatic wheel lifting mechanism.


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

Loaded wheel system
This Universal model is fitted with double stainless steel wheel, 203 mm dia. x 47 mm wide, and double solid rubber tyre, 203 mm dia. x 50 mm wide.
The wheel load is adjustable in 100 N steps from 700 to 1500 N (for 77-PV33D05-06 only). The system includes a motorized lifting system of 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 over a range of 25 to 70°C ± 1.0°C, whilst the EN requires either air or water environment. In both systems 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.  All versions fully satisfy and exceed  the above requirements: the temperature accuracy is ±0.5°C.

Temperature controlled cabinet
The Universal AASTHO/EN versions feature an inbuilt temperature controlled cabinet for testing in air or in water, designed to avoid condensation problem (in water testing) and prevent overtemperature which may damage the mechanical parts or alter the transducer accuracy. Furthermore the system ensure thermal stability and provides rapid test start when the conditioned temperature has been reached.

Impression measurement system
Each wheel is fitted with linear transducer measurement system for deformations 0 to 50mm ±0.01mm.
More +

Technical specifications

  • Displacement motion: the arm is moving and the carriage is fixed
  • Wheel travel: 230 mm
  • Wheel speed: variable from 20 to 30 cycles/min
  • Wheel load: 700/705 N by weigths (78-PV33B05/6 models), adjustable from 700 to 1500 N in 100 N steps (78-PV33D05/6 models)
  • Temperature range: ambient to 80°C, ± 0.5°C 
  • Rut depth transducer range: 25 mm, 0.01 mm accuracy
  • Moulds: not included, to be ordered separately
  • Slab thickness: adjustable from 40 to 100 mm in 10 mm steps
  • Overall dimensions (w x d x h): 1540x1020x1600 mm
  • Weight approx.: 600 kg
  • PC and software: included
Models 78-PV33B05   78-PV33D05 (1500 N)
78-PV33B06   78-PV33D06 (1500 N)
Standards AASTHO T324 / EN 12697-22
Testing mode In air and water
Description DWT, Hamburg and EN type, double wheel tracker, interchangeable wheels (steel for AASTHO and rubber for EN), wet and dry conditioning
Material and dimensions (diameter per width) of the two loaded wheels Stainless steel 203x47 mm
Rubber tyre 203x50 mm
Temperature control method (accuracy ±0.5°C for both water and air) Air: Three 1200 W electronically controlled air blowers
Water: Three 1500 W heaters, re-circulating pump, automatic feed and control level
Power rating 5500 W


Ordering info

78-PV33B05
DWT Wet and dry universal double wheel tracker

Conforming to Hamburg type AASHTO T324 and EN 12697-22 Small Size Device, in-air and in-water conditioning. Complete with both stainless steel and rubber wheels, laptop PC, software and clear transparent sliding doors. Set of moulds to be ordered separately. 
380 V, 50 Hz, 3 ph+N

78-PV33B06
As above but 220 V, 60 Hz, 3 ph

78-PV33D05
DWT Wet and dry universal double wheel tracker
Wheel load adjustable up to 1500 N (by 100 N steps). Conforming to Hamburg type AASHTO T324 and EN 12697-22 Small Size Device, in-air and in-water conditioning. Complete with both stainless steel and rubber wheels, laptop PC, software and clear transparent sliding doors. Set of moulds to be ordered separately.
380 V, 50 Hz, 3 ph+N

78-PV33D06
As above but 220 V, 60 Hz, 3 ph

Accessories

78-PV3/001
Set of two moulds for 400x300 mm samples, thickness from 40 to 100 mm, recommended for test according to EN 12697-22 in water or in air.

78-PV3/002
Set of two moulds for 360x300 mm (also suitable for 320x260 nn samples by using 20 mm thick plaster spacers), thickness variable from 40 to 100 mm. 

78-PV3/003
Set of two moulds adaptors for double 150 mm dia. core (total 4 adaptors made of special self lubricating acetal copolymer), thickness 60 mm, fitted in 77-PV3/002 360x300 moulds (not included). 

78-PV3/005
Set of trays with handles for double 150 mm diameter cylindrical samples. 77-PV3/003 adaptors for 150 mm dia. cylindrical sample to be ordered separately 

78-PV3/011 
Set of two moulds 400x300 mm, 38 to 120 mm height

78-PV3/012
Set of two moulds 360x300 (suitable for 320x260 mm slabs), 38 to 120 mm height

Upgrading

To be specified at time of order

Lifting system
78-PV3UP10 
System for the independent lifting of the loading wheel at the rut target, continuing the test, without interruption with the other wheel.


Additional temperature probes
78-PV3UP20 
Additional two temperature probes to monitor the two sample temperatures.

Documents