GB1283460A - Device for measuring the gripping capacity and resistance to wear of road construction materials - Google Patents

Abstract

1283460 Testing road materials WIBAU WESTDEUTSCHE INDUSTRIE-UND STRASSENBAU MASCHINEN GmbH 23 Sept 1970 45354/70 Heading G1S A device for testing road materials for gripping capacity and resistance to wear comprises a wheel 1 mounted on a shaft 2 journalled in a chassis 4 and hydraulic or pneumatic rams 6 for displacing the wheel towards a test surface, the chassis being secured to a frame 13 having clamps 15 for holding test sample 16 for carrying out laboratory tests but being capable of being detached from the frame and attached to a running chassis for carrying out tests on finished roads. Shaft 2 is driven by an electric motor 9 at a variable speed through belts 8 and clutch 7, the speed of the shaft being measured by a tachogenerator and the torque delivered by the motor being measured by measuring the current consumption. The force between the wheel and test sample 16 is measured at 23 and this force, the motor current and shaft speed are displayed on a recorder, Fig. 4 (not shown). The sample holder 15 is free to rotate about shaft 17 and the shaft may be moved laterally to adjust the axis of rotation relative to the wheel. A pump 19 is provided to pump water from tank 20 on to the sample. In one method of use a test sample, which may be taken from a road, is mounted in clamps 15, a pre-selected pressure applied to the wheel and the wheel is rotated at a given speed. The torque of the motor is then a measure of the grip between the wheel and the sample. The wear is measured by determining the loss in weight of the sample. In an alternative method of use the wheel is rotated at a preselected speed, the clutch is disengaged and the wheel is then applied to the sample with a given pressure, the slowing down of the wheel being monitored to give a measure of the grip between the wheel and the sample.