Test of softening point on bitumen
Softening point denotes the temperature at which the bitumen 40/50, 60/70 and bitumen 80/100 attains a particular degree of softening under the specified condition of test. The test is conducted by using Ring and Ball apparatus. A brass ring containing test sample of bitumen 40/50,60/70 and bitumen 80/100 is suspended in liquid like water or glycerin at a given temperature. A steel ball is placed upon the bitumen 40/50, 60/70 and bitumen 80/100 sample and the liquid medium is heated at a rate of 50C per minute. Temperature is noted when the softened bitumen 40/50,60/70 and bitumen 80/100 touches the metal plate which is at a specified distance below. Generally, higher softening point indicates lower temperature susceptibility and is preferred in hot climates.