Materials Testing - Wheel Tracking

CRT-WTEN1 & CRT-WTEN2 & CRT-WTAUS Wheel Tracker Small Device
Wheel tracking is used to assess the resistance to rutting of asphaltic materials under conditions which
simulate the effect of traffic. A loaded wheel tracks a sample under specified conditions of load, speed
and temperature while the development of the rut is monitored continuously during the test. Test
specimens can be either slabs prepared with a laboratory compactor or 200mm Ø cores cut from the
highway.

The CRT-WTEN1 wheel tracker performs both procedures A and B specified for the small scale device in
EN 12697-22. Procedure A requires that six specimens are tested. For procedure B, only two specimens
need to be tested, but rut depth must be measured at more points along the longitudinal rut profile. To
speed up the testing process, the CRT-WTEN2 was designed to test two specimens simultaneously.

Key Uses
Determination of the rut resistance of asphaltic paving materials

Standards
EN 12697-22 Small device
AST 01:2004
BS 598-110:1998

Key Features
Test materials for roads with axle loads up to 13 tonnes
Rigid test frame built from extruded aluminium section
Integral temperature controlled cabinet with double glazed doors
PID control of test temperature in the range of 40ºC to 62ºC
Rack for pre-test temperature conditioning of specimens
The CRT-WTEN2 tests two specimens simultaneously
Specimens compacted with Cooper Technology Roller Compactor can be transferred directly to the wheel tracker without
de-moulding
Closed-loop speed control
User-friendly Windows™ software
Supplied with certification of a UKAS accredited calibration

CRT-WTENLD Wheel Tracker Large Device
Wheel tracking is used to assess the resistance to rutting of asphaltic materials under conditions which
simulate the effect of traffic. In this machine, two 500x180mm specimens are tested simultaneously by
tracking with wheels fitted with pneumatic tyres under specified conditions of load, speed and temperature
while the development of the rut profile is monitored at specified intervals during the test. The moulded
specimens are inserted and removed from the wheel tracker using an Easy-load system.

A unique instrumented measurement device, linked to the data acquisition, is used to measure the
development of rutting during testing. The test procedure and conditions are controlled and data acquired
using Windows™ software running on a host computer via a high speed digital interface and signal
conditioning system.

Key Uses
Determination of the rut resistance of asphaltic paving materials

Standards
EN 12697-22 Large device
NF P98-253-1

Key Features
Test materials for roads with axle of at least 13 tonnes
Unique rut profile measurement device linked to data acquisition system
Integral temperature controlled cabinet
Test temperature range 40 to 60ºC
Tests for specified number of cycles or to specified rut depth
Double glazed doors for viewing test
Easy-load system for specimen handling
Conditioning of specimens at test temperature
User friendly Windows™ software
Automatic test start/stop
Closed loop speed control
Specimens can be compacted in the CRT-RCENLD-II and then wheel tracked without demoulding
Supplied with certification of a UKAS accredited calibration

Wheel Tracking systems provide software control and data acquisition

Software

User friendly, intuitive and reliable Windows™ software developed using LabVIEW™
Software is designed to perform EN 12697-22 Small device
Software automatically starts the wheel tracker, maintaining the speed at the specified 26.5 cycles per minute
Measures rut deapth and sample temperature automatically at regular intervals
A continuously updated on-screen graph shows rut depth versus time, along with the rut profile and temperature
Software stops the wheel tracker on completion of a test and prints a test if required
Stored test data can be analysed and compared with other test data utilising a spreadsheet package
Utilities are included for transducer check, diagnostic routines and RTD calibration