Cylinder compression and wheel tracking device

Standard: EN 12697-33, EN 12697-22

The feature of the machine is the combination of two different functions in a single system; The first is to ensure the compression of bituminous mixture plates to a controlled density, and the second is to perform the wheel tracking test.

A "kneading" system is used for compression and consists of a series of sliding metal plates positioned between the roller and the bituminous mixture, which are free to move vertically and are guided by the inner mold surfaces.

The wheel tracking test device is of the "small size" type as specified in the Standard.

The integration of the two functions is made possible by a special machine design (patented); the cylindrical roller is replaced by two coaxial disks that roll along the lateral protrusions of the sliding plates.

When removing the plates, the disks are lowered to the other two edges of the mold, thus making contact between the bituminous mixture surface and the wheel of the wheel tracking apparatus.

Mechanically, the machine consists of a vertical axis driven by a brushless motor combined with a ball screw assembly and a Bellofram cylinder controlled by a horizontal pneumatic servo valve.

There are three sensors mounted on the machine: an incremental encoder for horizontal axis position, a magnetostrictive sensor for vertical axis position, and a load cell for force.

Each of these sensors can be used as a reference by the closed-loop, computer-controlled system with feedback; the user interface is a touch screen.

The test area is placed in a ventilated climate chamber with automatic thermo-regulation up to 60 °C.

Roller Compression

To obtain plates of the desired density and size, an initial leveling cycle designed to evenly distribute the mixture in the mold can be run.

The compression phase can be programmed with a constant or increasing load, i.e., with increasing deformation. It is possible to set a defined laying thickness or number of cycles.

Wheel Tracking

The compact roller's refined transmission, control, and operating system remains active during the wheel tracking test to compensate as much as possible for the inertial effects of the load mass due to wheel depth imbalances.

Both procedures specified by the Standards can be performed.

User Interface

Users need to enter basic parameters and procedures; Test application, measurements, data processing, and test report compilation are fully automatic.

Power supply: 380 V, 50 Hz, 16 A, three phase + N + E, 6000 W

Air supply: 10 bar pressure; dry, unlubricated air (compressor and accessories not supplied)

Dimensions: 1850 x 800 x 1990 (h) mm

Weight: 800 kg