PAVELAB DWT Double Wheel Tracker, EN version

Introduction

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. Two versions available as prescribed by EN 12697-22 Small Size device: specimen conditioning in air (model 77-PV32E05) and in air or water (model 77-PV33E05).
Both versions 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.
We also produce Wheel Trackers conforming to AASHTO T324 standard and a universal version conforming to both AASHTO and EN standards. See Hamburg type double wheel tracker and Universal AASHTO/EN double wheel tracker.

Description

• Machine body

Sheet steel, powder coated. Transparent sliding door.

• Loaded wheel system

AASHTO Hamburg Type versions are fitted with double stainless steel wheel, 203 mm dia. x 47 mm wide, whilst the EN versions are fitted with double solid rubber tyre, 203 mm dia. x 50 mm wide. The wheel load (for both systems) is 700 N. The system includes a motorized lifting system of the wheel assembly at the end of the test avoiding the use of obsolete hoists.
The combined AASHTO/EN versions (see model 77-PV33B05) are supplied complete with both set of stainless and rubber wheels. This solution is particularly suitable for Central and Research laboratories.

• Wheel tracking carriage

The test specimens in their carriages are moved 230 mm backwards and forwards under the loaded wheels in a fixed horizontal plane. The speed is adjustable via PC from 20 to 30 cycles per minute (40 to 60 passes). The slab mounting system can hold specimens of 320x260 and 400x300 mm, 38 to 100 mm thick. The greatest slab dimension is oriented as the wheel travel. Special slab moulds for circular samples
from coring or gyratory compactors, are also available. See accessories.

• Temperature control system

AASHTO Hamburg Type standard prescribe the test to be performed in a water bath over a range of 25 to 80°C ± 0.5°C, whilst the EN prescribe either air or water environment. In both systems a water level of about 20 mm above the sample has to be maintained. In case of air heat environment, the specimen, during testing, must be maintained at uniform and constant specified temperature ± 0.5°C. DWT PAVE-Track versions, fully satisfy and exceed the above requirements: the temperature accuracy is ± 0.5°C.

• Impression measurement system

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

• Testing software

User friendly Windows® software. The operator can set the (fully customizable) test execution conforming to standards following in real time the test evolution: water (or air) temperature, specimen temperature, rut depth, and the graph deformation/cycles with the specimen profile, metric or Imperial unit selection.
Export test data to CSV Format (Excel), file management concerning tests, asphalt mix, clients, etc.

• Safety features

Display of the actual software setting concerning the selected temperature control system: water or air, giving the operator the possibility to check if the machine is mechanically set conforming to the standard in use.
The machine stops automatically opening the protection.
Air temperature overheating protection system.
Motor protection and other standard safety applications.

• Standard outfit

The machine is supplied complete with laptop PC, Testing software. Set of moulds to be ordered separately (see accessories).