Asphalt penetration is one of the main quality indexes of asphalt. It is an index that indicates the degree of hardness and consistency of asphalt, the ability to resist shear damage, and reflects the relative viscosity of asphalt under certain conditions. At 25 ° C and 5 seconds, under a load of 100 grams, the depth of the standard cone into the asphalt sample vertically is the penetration of the needle, in 1/10 mm.
