Study on the effects of the softening point of bitumen

Differences always occur in the softening point testing results when a same sample of bitumen is tested in different labs.Besides the factors from personnel,the using of different testing apparatus is the main cause of errors.In order to know the effects of instrument on softening point,the paper studied the effect of support plate shape and height,mixing and sample ring structure on the influence of softening point.The results showed that the softening point got from large oval support plate was about 1.2 ℃ higher than that got from small rectangular support plate.But the height of support plate had less affected on the softening point,even can be neglected.To a certain extent,mixing could affect the softening point,and according to the shape of the support plate,the influence of mixing on softening point was different,this was about 0.3 ℃,and the mixing can increase the influence of support plate on the softening point.In the study,the softening point got from shoulder rings was about 0.5 ℃ more than the result got from inclined ring.