Automatic Ball & Ring | Performance

The test is about determining the softening point of bitumen and bituminous binders for temperatures ranging from 28 °C to 150 °C. Two horizontal bitumen rings, molded in shouldered brass are heated in a liquid bath with a controlled temperature rise of +5°C per minute, while each supports a stainless steel ball of defined size and weight .

The final softening point value is the average of the temperatures at which the two rings soften enough to allow each ball, wrapped in bituminous binder, to get in contact with the bottom plate (25 ± 0.4 mm below the rings).