Development of laboratory protocols for the ageing of asphalt mixtures

Laboratory protocols for the long and short-term ageing of bitumen have been developed and are routinely used in practice. The ageing process, however, depends to an extent on the asphalt mixture in which the bitumen is placed and protocols for the ageing of mixtures have not been universally agreed. The manufacture of test specimens from compaction of bituminous mixtures prepared in the laboratory is carried out using a wide variety of procedures. These depend on the facilities available and often result in storage of hot material causing short-term ageing of the binder which is not representative of full-scale production conditions. In order to determine a laboratory protocol which did reproduce field conditions, studies were conducted in conjunction with six contractors and in the laboratory through varying the ageing period at 135°C. Both continuous and gap-graded materials were investigated. The stiffness modulus under standard conditions was used to judge the extent of ageing through the increase in stiffness caused by this process. By comparing results of laboratory and plant-mixed material compacted to the same void content, the hot storage period required in the laboratory was determined. This was shown to be mixture dependent and varied from 0 to 2 hours. A long-term ageing protocol was also assessed. This was intended to reproduce the in-service ageing that occurs over many years in the field. A range of mixtures was used and the protocol, involving exposure to a temperature of 85°C for 120 hours, was shown to distinguish between mixtures normally regarded as durable (dense, gap-graded) and those likely to be susceptible to ageing (lean with high void content).


  • English

Media Info

  • Pagination: 83-90 (Book 1)
  • Monograph Title: Proceedings of the papers submitted for review: Eurasphalt and Eurobitume Congress

Subject/Index Terms

Filing Info

  • Accession Number: 01392438
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Aug 23 2012 7:08AM