Thermo-rheological analysis of WMA-additive modified binders

Abed, Ahmed; Thom, Nick; Lo Presti, Davide; Airey, Gordon

Abstract

Thermo-rheological characteristics of unmodified and modified bitumen have significant impacts on the mechanical response of asphalt. This study investigates the impacts of an organic and a chemical Warm Mix Asphalt additive on bitumen thermo-rheological and mechanical characteristics. Modified binders with different concentrations of each additive were studied and analysed comparatively to a 40/60 penetration grade bitumen. Frequency sweep tests were performed at different ageing levels to characterise the Linear Viscoelastic properties. The multiple stress creep and recovery, linear amplitude sweep (LAS) and low temperature creep stiffness tests, together with the Glover–Rowe (G–R) fatigue parameter (determined from fitting of the 2S2P1D model to the complex shear modulus and phase angle master curves) were used to analyse the performance of the binders at critical operating temperatures. The results demonstrated the necessity to analyse the behavior of the studied binders beyond the limits of linear viscoelasticity to better characterise these types of bitumen. The results also indicated that both additives retarded bitumen ageing with the organic additive increasing bitumen elastic response while the chemical additive increased its viscous response. The results also showed an excellent correlation between the G–R parameter and LAS results which suggests the ability to use this parameter in characterising fatigue performance of the studied binders. This also suggests that bitumen fatigue life may be improving over time due to the increased elastic behahviour during ageing so long as a certain critical level of ageing is not reached.

Citation

Abed, A., Thom, N., Lo Presti, D., & Airey, G. (2020). Thermo-rheological analysis of WMA-additive modified binders. Materials and Structures, 53(3), Article 52. https://doi.org/10.1617/s11527-020-01480-1

• Journal Article Type: Article
• Acceptance Date: Apr 7, 2020
• Online Publication Date: Apr 29, 2020
• Publication Date: 2020-06
• Deposit Date: May 1, 2020
• Journal: Materials and Structures
• Print ISSN: 1359-5997
• Electronic ISSN: 1871-6873
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 53
• Issue: 3
• Article Number: 52
• DOI: https://doi.org/10.1617/s11527-020-01480-1
• Keywords: General Materials Science; Mechanics of Materials; Civil and Structural Engineering; Building and Construction
• Public URL: https://nottingham-repository.worktribe.com/output/4371015
• Publisher URL: https://link.springer.com/article/10.1617/s11527-020-01480-1
• Additional Information: Received: 19 November 2019; Accepted: 7 April 2020; First Online: 29 April 2020; : ; : The authors declare that they have no conflict of interest.