METHOD OF DETERMINING PENETRATION DEPTH OF A NEEDLE FOR BITUMEN BINDER Russian patent published in 2020 - IPC G01N33/42 

FIELD: test technology.

SUBSTANCE: invention relates to laboratory methods of testing road-building materials. Method comprises heating bituminous binder sample at (90±10)°C above softening point but not lower than 120 °C and not higher than 160 °C, pouring bituminous binder into the penetration cup and holding it in air at a given temperature for a predetermined time, placing a penetration cup with bitumen binder in a reservoir for temperature control with water heated to test temperature, and holding in it for a predetermined time, after which a penetration cup with bitumen binder is removed from the temperature control reservoir and placed in a flat-bottomed vessel with capacity of not less than 0.5 dm³, filled with distilled water so that the height of the liquid above the surface of the bituminous binder is not less than 10 mm, and its temperature corresponds to the test temperature. Then, flat-bottomed vessel is installed on the penetrometer column and penetration depth of the needle is determined, wherein determination of the penetration depth of the needle is carried out at least three times in different points on the surface of the bitumen binder sample, spaced from the cup edges and from each other by at least 10 mm. Result of the test is the average of the results of at least three determinations, rounded to the nearest integer. Note here that cups of minimum possible sizes are selected for the test, which correspond to assumed depth of needle penetration, and to calculate cooling and temperature control time in cups preset design ratio is used.

EFFECT: reduced time for preparation of bituminous binder sample for testing under conditions that the obtained results will be in the zone of convergence.

1 cl, 2 dwg