The wheel tracking apparatus consists of a loaded wheel, which bears on a sample held on a moving table. The sample may be either a 200 mm diameter core or a 300 x 400 mm slab of asphaltic mixture from 25mm to 100 mm thick. A 25 mm stroke LVDT transducer is included for monitoring rut depth in the centre of a sample during a test to better than 0.1 mm. The table reciprocates with simple harmonic motion through a distance of 230 ± 5 mm with a frequency of 53 passes (± 1%) per minute. For reasearch purposes the test speed can be adjusted by inverter control. The wheel is fitted with a solid rubber tyre of outside diameter 200 mm. The wheel load under standard conditions is 700 ± 10 N. The wheel tracker is fitted with a temperature controlled cabinet with a temperature range from environment to 65°C ± 1.0°C. The deformation and sample temperature is recorded by the internal data acquisition and control system, then sent to the Windows compatible software.

Main Features:

Real time display of number of cycles, rut depth and temperatures

Tracks for specified number of passes or to specific rut depth

Adjustable load cycle frequency

Automatic test control by data acquisition and processing system

Large permanent memory to store test data and results

Double temperature measurement: inside the specimen and in the cabinet

Test temperature range from ambient to 65°C

Testing software included for procedures EN, A and B, and custom defined

Motorized loading arm for easy positioning

Double glazed doors for observation of testing cycle.

Technical Specifications

Wheel Tracker:

Table displacement with adjustable speed by inverter

Motorized vertical adjustment of the loading arm

Suitable for large core specimens and slabs up to 400x300 mm.

Slab thickness from 25 to 100 mm

25 mm stroke transducer with resolution better than 0.1 mm

Wheel with solid rubber tyre 200 mm external dia.

Wheel weight 700 N (900 N available on request)

Integral temperature controlled cabinet

Double glazed doors for test monitoring

Test temperature range adjustable from environment to 65°C

Hardware

16 bit microprocessor.

10 key membrane touch keyboard.

240 x 128 pixel graphical display.

One CPU card to control both test data visualization, temperature control, database and internal functions management control.

Large permanent memory to store test results.

RS 232 output for PC connection.

Firmware

Fully automatic test control

Language selection.

Clock/Calendar system.

Download to PC via RS 232 serial port.

Data processing to Small scale device, procedure A and B, and customized test

Test setting menu, complete with descriptive sample parameters.

Calibration menu to set and check temperature, table speed and displacement, and featuring a special function for manual control of the test performance.

Test performance menu with simultaneous display of all the test data (including real time table speed).

Internal database up to 100 tests. Each test can be downloaded to a PC, displayed, printed or deleted.

Safety Features:

Automatic stop of climatic chamber and moving table when opening the door.