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RESEARCH PRODUCT
Thermo-rheological analysis of WMA-additive modified binders
Ahmed AbedGordon AireyDavide Lo PrestiDavide Lo PrestiNick Thomsubject
Materials science0211 other engineering and technologiesStiffness020101 civil engineering02 engineering and technologyBuilding and ConstructionViscoelasticitySweep frequency response analysis0201 civil engineeringShear modulusCreepRheologyMechanics of MaterialsAsphalt021105 building & constructionSolid mechanicsAgeing Bitumen rheology Fatigue Low-temperature cracking Rutting Warm mix asphalt (WMA) additivesmedicineSettore ICAR/04 - Strade Ferrovie Ed AeroportiGeneral Materials ScienceComposite materialmedicine.symptomCivil and Structural Engineeringdescription
AbstractThermo-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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-04-29 | Materials and Structures |