Investigation of The effect of different methods of long-term aging on the fatigue performance of asphalt mixtures

Document Type : Scientific - Research

Authors

1 Associate Professor, Payam Noor University, Tehran, Iran

2 Ph.D. candidate, Payam Noor University, Tehran, Iran

3 Associate Professor, Department of Civil Engineering, Faculty of Engineering, University of Zanjan, Tehran, Iran

Abstract

Abstract:
Bitumen aging is one of the factors causing and spreading cracks and moisture damage in asphalt pavements. Aging can occur during the production, transportation, and construction stages (short-term aging) or the operation period (long-term aging) and can cause bitumen to harden. Today, various methods are defined to simulate short-term and long-term aging. In this study, the effect of long-term aging of AASHTO R30 (as the most common standard method) and NCHRP 9-54 (as the latest method) on the fatigue performance of asphalt mixtures was investigated at strain levels of 500 and 1000 microstrains, loading frequencies of 5,10,15, and 25 Hz and temperature of 200c using a 4-point bending beam test. The results showed that both aging methods increased the initial stiffness and decreased the fatigue life of the samples at the strain levels and loading frequencies tested. Also, by comparing the fatigue life of the tested samples, it was found that the greatest reduction in fatigue life was related to the aged samples by the AASHTO R30 aging method. According to these results, it can be said that AASHTO R30 is a conservative method in comparison with NCHRP 9-54.

Keywords



Articles in Press, Accepted Manuscript
Available Online from 01 February 2023
  • Receive Date: 14 September 2022
  • Revise Date: 16 January 2023
  • Accept Date: 29 January 2023