Blending Charts Based on Performance-Graded Asphalt Binder Specification (original) (raw)
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Transportation Research Record: Journal of the Transportation Research Board, 2018
In the paving industry, there is increased interest in using recycled materials like recycled asphalt shingles (RAS) and reclaimed asphalt pavements (RAP) due to the valuable asphalt binder contained within them. The major concern with using these materials is that the binder they contain is highly aged, which could lead to reduced mixture durability. Therefore, a method is needed to quantify the extent to which the aged binders from these materials blend with virgin binder when producing mixtures in order to understand better their effects on mixture performance. In this study, a new approach to quantify the amount of blending that occurs between aged RAS and RAP binders and a virgin binder was developed. Asphalt binders were extracted and recovered from RAS and RAP stockpiles and blended with a PG64-28 virgin binder in varying proportions. The master curves of these mixtures were constructed at 20°C. Asphalt mixtures containing different proportions of the same RAS and RAP stockpi...
Construction and Building Materials, 2011
The objective of this paper is to provide a methodology for determining the degree of partial blending in high RAP mixtures. When RAP is mixed with virgin aggregates and virgin binder, partial blending of RAP binder occurs in the hot mix asphalt. Agencies limit the amount of RAP because the degree of blending between the RAP and the virgin materials is not known. The methodology provides a systematic approach for determining the degree of partial blending in the RAP mixture. The ability to accurately determine the degree of partial blending will help in determining the virgin binder content to be added in the mixture. The degree of partial blending measured from this procedure for 25% RAP by weight of aggregates with PG 70-28 and 35% RAP by weight of aggregates with PG 58-28 are 70% and 96% respectively.
Evaluation of a newly developed asphalt binder selection system for mix design
2005
A Norwegian research project (PROKAS) has been conducted in the period 1998 – 2004. One objective was to develop performance-based specifications for Norwegian asphalt mixtures. As a part of this project a new binder selection system was sketched (Andersen, 2000). This system was based on results from the Norwegian research project New Asphalt technology, a project aiming at adaption of the Superpave binder system to Norwegian conditions. An attempt to verify this binder selection system in the laboratory has been made. Deformation properties of asphalt mixtures with different binder stiffnesses have been measured (Lerfald, 2004). The same aggregates and material gradings were used in all samples. The new asphalt binder selection system shows relatively good correlation with results from the deformation tests. However, further testing with other mixtures and higher temperatures will be required to fine-tune and fully verify the system.
Acta Technica Jaurinensis
Reclaimed asphalt pavement (RAP) is gained from road reconstructions; however, its usage is less optimised in Hungary and neighbouring regions, since on the project level the proportion of RAP in the asphalt mixes is only 10-15%. This is less than the recommended level in other EU countries. The higher usage of RAP provides economic and environmental advantages, decreasing the need for new materials, the transport cost, and the carbon footprint. The composition of the resultant bituminous binder blend is a critical element in the asphalt mix design with high RA content. This paper discusses the design of the resultant bituminous binder blend to provide performance and compliance characterisation. This paper also presents the complex rheological analysis of the base bitumen, the bitumen extracted from the RA and the bituminous binder blend, applying the dynamic shear rheometer (DSR) device. It was shown that for paving grade bitumen (B), polymer modified bitumen (PmB) and rubber modi...
Journal of Materials in Civil Engineering, 2015
In this study, the rheological properties and activation energy (AE) of unaged and aged asphalts blended with different percentages of binder, recovered from three reclaimed asphalt pavement (RAP) sources, were investigated. Superpave asphalt binder tests were used to evaluate the effects of the recovered asphalt binder source and content. The results indicated that the addition of recovered binder from each source increased the viscosity, G Ã = sin δ, and G Ã sin δ. The increase in viscosity per 1% recovered binder was evaluated using nondimensional viscosity index (∇η RAP). In addition, the increase in G Ã = sin δ and G Ã sin δ per 1% recovered binder were investigated using relative Superpave rutting gradient (RSRG) and relative G Ã sin δ gradient (RG) factors, respectively. The results indicated that the ∇η RAP , RSRG, and RG depended on recovered binder source, content, aging, and test temperature. The interpretation of the AE results depended on the physical phase of the asphalt blends, irrespective of the recovered binder source and content. The AE increased when the physical phases of the asphalt blends were in liquid and semiliquid (high phase angle) states over the range of temperatures tested compared with the control asphalt binder. However, the AE decreased when the physical phase of the asphalt blend samples was solid (low phase angle).
2019
The road to sustainability passes through the process of recycling a greater amount of asphalt pavement. Inclusion of additional amounts of reclaimed asphalt pavement (RAP) in new mixes has become a prominent method to promote sustainability. This research addresses some of the challenges related to high RAP content mixes. Among the factors considered are the impact of rejuvenator diffusion on binder stiffness, stiffness gradient, performance grade, homogeneity, and ultimately, their effects on mix performance. In this project, an experiment was conducted to evaluate the effects of the rejuvenator type, dosage rate, and mix-aging protocol on recycled binder homogeneity and mix performance. Another experiment was conducted to evaluate the ability of several simulated aging protocols to produce a binder stiffness and stiffness gradient similar to those observed in natural aging. The results show that the target high temperature grade of a recycled mix should be set at 6 o C higher than that of virgin mixes. In general, mixes with a high temperature grade of 6 o C higher than a virgin mix performed better in rutting and comparably in cracking. There is a strong correlation between binder stiffness gradient and cracking performance. The best simulated aging protocol was to heat the mix to 110 o C for 4 days. These results were based on five mixes and a total of 15 mix/aging protocol combinations.
Performance and blending evaluation of asphalt mixtures containing reclaimed asphalt pavement
Road Materials and Pavement Design, 2020
This study aims to (1) determine an optimum amount of Reclaimed Asphalt Pavement (RAP) such that its addition does not adversely impact the fracture resistance of asphalt mixtures, and (2) determine the amount of RAP binder that is active in the total mix. For this purpose, the asphalt mixtures containing three RAP contents (15, 25 and 35%) and their recovered binders were characterized. The binders were subjected to the performance grading, frequency sweep, multiple stress creep and recovery (MSCR) and linear amplitude sweep (LAS) tests. The mixtures were evaluated using dynamic modulus, Hamburg Wheel Tracking (HWT), Flow Number (FN), Semi Circular Bend (SCB), and Ideal Cracking Tolerance (Ideal-CT). The blending efficiency of the RAP binder was determined using the Hirsch model. Based on the performance results and the relatively low binder content of asphalt mixtures in Qatar, it is recommended to use up to 20% RAP in asphalt mixtures.
Development of Asphalt Binder Performance Grades
Proceedings of International Structural Engineering and Construction, 2014
Asphalt plays a significant role in a pavement’s ability to withstand thermal and fatigue cracking that contributes to permanent deformation behavior. Temperature is a significant factor that affects asphalt binder and thus the performance and life span of the whole pavement. This paper presents research developing asphalt binder performance grade requirements, according to Superpave, suitable for different climatic conditions all over Egypt. Twenty one weather stations covering Egypt were selected, then after analysis their air temperature data was converted to pavement temperatures using LTPP and performance models. Finally, the converted pavement data were used to propose asphalt binder performance grades (PG) for the various regions of Egypt. The proposed grades range from PG52-10 to PG76-10 depending on the location, the applied model, and the degree of project reliability.
Performance Characterization of Polymer Modified Asphalt Binders and Mixes
Fatigue sensitivity of four different asphalt binders and three different asphalt mixes was evaluated in the study. Binders were subjected to Linear Amplitude Sweep (LAS) test at three temperatures of 10, 20, and 30 ∘ C. Four-point beam bending test (4PBBT) was conducted on the asphalt mixes at a temperature of 20 ∘ C for strain amplitudes varying from 200 to 1000 microstrains. Tests like retained Marshall Stability and indirect tensile strength (ITS) were also carried out to judge the mix performance. Experimental studies demonstrated that elastomeric modified binder and mixes gave the best performance in fatigue. Plastomeric modification was found to be highly strain susceptible and resulted in poor fatigue performance. The fatigue life of stone mastic asphalt (SMA) was found to be almost five times higher than the dense graded mixes. For similar strain levels, the results of LAS test could be linearly correlated with the 4PBBT results.