Microbial degradation of asphalt

Bitumen Attack by Microorganisms

“…The difference in susceptibility of bitumen to bacterial action is further supported by laboratory experiments (9). It was demonstrated that Bacillus 11-2A isolated by enrichment culture would readily attack asphalt 6A and utilize bitumens "A" and "E" to a lesser extent, but was unable to utilize asphalt "G."…”

“…However, it is likely that microbial action accounts for the major portion of the loss. Earlier reports (7,9) cite degradative activity of a number of pure cultures on a single asphalt under laboratory conditions. In these experiments the rate of breakdown was rapid, 3 to 25% degradation occurring within 1 week of exposure under optimum conditions of temperature, pH, and aeration.…”

Asphalt Material Aging Mechanism and Characteristics Analysis Based on Infrared Spectrum

“…Scholars study asphalt aging mechanism and its affect to pavement performance for a long term.In 1903, A.W.Dow first proposed asphalt aging reason, it is that asphalt heating due to the mass loss and the decrease of penetration [2].In 1961,Traxler derived the reason of asphalt aging is evaporation of light components, oxidation, photopolymerizable and so on [3].Petersen studied the dynamic viscosity with aging time change at 60℃ of the asphalt in the process of long-term aging [4].With the progress of the chemical analysis technique, many scholars studied aging mechanism of asphalt means by chemical analysis methods,and the study of asphalt aging become form changes of the macroeconomic indicators to the microcosmic.Herrington test the molecular weight distribution changes of asphalt before and after aging [5].Shui Hengfu explored asphalt aging by H-NMR combined with IR [6].…”