Effect of warm mix additives on compactabilitiy of mixtures

Pamuk, Ömer Can
Warm Mix Asphalt (WMA), the technology that allows significant reduction in the mixing and compaction temperatures of asphalt mixtures, has been commonly used globally since the early 2000s. This study evaluates the effect of compaction temperature (CT) on WMA and Hot Mix Asphalt (HMA) mixtures volumetrics, degradation, stability, and compactability properties. Although both Superpave Gyratory Compactor (SPGC) and Marshall hammer are used for sample preparation, the focus of this study is to develop compactability parameters for mixtures compacted with Marshall hammer, since SPGC is not sensitive to temperature changes. Besides, current compactability related studies are not capable of assessing the influence of temperature changes. Therefore, in this study, an image-based method and a testing setup are developed to obtain the densification/compaction curves. In order to analyze the effect of CT, the test matrix includes one HMA and four different WMA mixtures; prepared with a non-foaming additive (Sasobit) and a foaming additive (Advera) at two different dosages. CT’s are selected as the typical CT of HMA (140 °C), 15, 30, 45 °C lower than this temperature. It was concluded that pavements constructed with WMA additives at lower temperatures could meet the performance of HMA pavements constructed at traditional temperatures. In addition, the degradation patterns are similar for WMA and HMA mixtures. Finally, the compactability parameters calculated from Marshall densification curves meet the known field behavior of WMA and HMA mixtures, whereas it is not possible to drive the same relations from the parameters calculated from SPGC compaction curves.


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Warm Mix Asphalt (WMA) has been introduced to produce and place asphalt pavements at lower temperatures as compared to conventional Hot Mix Asphalt (HMA). While the WMA technologies are appealing, their long-term performance relative to HMA is not well-known. Among various WMA technologies, foam-based methods are the most widespread WMA applications. However, most of the current WMA design is based on empirical data and there is limited understanding of the fundamental behavior of the foamed binders and mix...
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Pamuk, Omer Can; Öztürk, Hande Işık (2021-04-01)
In practice, the production temperatures of Warm Mix Asphalt (WMA) mixtures are determined based on practical experiences and recommendations. Thus, the focus of this study is to propose a temperature-sensitive compactabilty assessment method to quantify the temperature needs of WMA mixtures. Therefore, in this study, an image-based testing setup coupled with the Marshall Apparatus was developed to obtain the densification curve of asphalt mixtures considering its sensitivity to temperature changes. Further...
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Kutay, M. Emin; Öztürk, Hande Işık (American Society of Civil Engineers (ASCE), 2012-06-04)
Foam-based Warm Mix Asphalt (WMA) technologies decrease the viscosity of the asphalt so that it is workable during construction. However, after construction, viscosity increases rapidly as the foam disappears and temperature drops. During the process of dissipation of foam, depending on the environmental conditions, the moisture may not escape and may be trapped inside the mixture. This trapped moisture can cause detrimental failures by breaking the adhesive bonds between the aggregates and the asphalt bind...
Effect of Aggregate Type and Rate of Temperature Change on Fracture Strength of Asphalt Concrete
Quadır, Adnan; Güler, Murat (2012-06-02)
One of the main distress types in asphalt concrete pavements is the low temperature cracking due to large variation of daily temperatures. Even though researchers around the world studied the effect of a number of mix design variables on the fracture strength of asphalt concrete, the rate of temperature change and the aggregate type have not been well elaborated in the previous researches and need further investigations. Several test methods have been suggested to study the low temperature behaviour of asph...
Effect of Conditioning Time and Temperature on the Volumetrics and Stability of Dry Process Crumb Rubber Modified Warm Asphalt Mixtures
Öztürk, Hande Işık (2017-11-17)
Environmentally friendly techniques for asphalt mixtures are developed for greater savings in natural resources, energy and economy. This paper focuses on the association of: i) Warm Mix Asphalt (WMA) ii) Dry Process Crumb Rubber (DryCR). WMA is a widely used technology that allows significant reduction in the mixing temperature (MT) and compaction temperature (CT) of the asphalt mixtures. Additionally, they have various acknowledged engineering, environmental and economic benefits. Similarly, CR modificati...
Citation Formats
Ö. C. Pamuk, “Effect of warm mix additives on compactabilitiy of mixtures,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Civil Engineering., Middle East Technical University, 2019.