Impact of addition of greasy diamide on the rheological-mechanical properties of warm-mix asphalt (original) (raw)
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Evaluation of the rheological behaviour of Warm Mix Asphalt (WMA) modified binders
Advanced Testing and Characterization of Bituminous Materials, 2009
Several processes and products are available to produce warm mix asphalt (WMA). The use of those may reduce the mixing and compaction temperatures in relation to hot mix asphalt (HMA), ensuring a good performance of the pavement. Lower plant mixing temperatures mean reduction in fuel consumption and lower emissions, what may contribute to diminish odours and health problems. A laboratory study on the properties of the modified binders (using two commercial WMA additives-Sasobit ® and Cecabase ®) was carried out through conventional (penetration, softening point), dynamic viscosity and rheology (DSR) tests, in order to establish the optimum additive content. Stripping of binder from the aggregates is a reported problem in WMA. Thus, the affinity of the modified binders was assessed without encountering significant problems. It was also observed that only Sasobit ® alters the viscosity of the binder. A maximum temperature reduction of 15°C was achieved using 4% of Sasobit ® with a softer binder.
Proceedings of 6th Eurasphalt & Eurobitume Congress, 2016
Foaming process and additivation of bitumens are now commonly used technologies to produce Warm Mix Asphalt (WMA). However, the mechanisms of such technologies are still not well understood. In this study, we focus on non-foaming WMA additives. A literature review shows that this kind of additives have only a slight impact on the viscosity of bitumens and allocates them lubricant and adhesion promoting properties. So they are thought to act at the surface of aggregates. In order to better understand their mechanisms during the mixing, lay down and compaction steps, both tribological and wetting experiments were conducted at high temperatures. On the one hand, friction experiments were conducted on a linear reciprocating tribometer in order to investigate the effect of additives on friction process between aggregates. In this test, a ball slides on a flat mineral aggregate immersed in hot bitumen. Both hydrodynamic and boundary lubrication conditions were investigated. On the other hand, the effects of WMA additives on the surface tension of neat bitumen were determined and the spreading of a drop of bitumen on the mineral aggregate was also investigated. Promising results indicate that organic and chemical additives don't get the same friction behaviour in boundary lubrication regime. Their contribution to surface tension is although discussed.
Investigation of the Properties of Warm Mix Asphalt Involving Organic Additive
2018
Demand for sustainable pavements increases day by day in asphalt paving industry. Warm Mix Asphalt (WMA) technology has begun to be an interesting topic for researchers owing to sustainability and environmental issues. Within the scope of this study, the effect of an organic WMA additive was evaluated in terms of mixture characteristics and performance. The fundamental and rheological properties of bitumen samples involving organic WMA additive were determined by conventional bitumen tests and dynamic shear rheometer (DSR). Mixtures modified with organic WMA additives were produced according to Marshall mix design method and the optimum bitumen content of the samples were determined. Following the determination of optimum bitumen content, the effect of the organic WMA additive was investigated in terms of indirect tensile stiffness modulus, fatigue and creep behaviour. Hamburg wheel tracking device was also applied to evaluate the permanent deformation characteristics of WMA mixture...
Rheological Properties of Asphalt Binder Modified with Chemical Warm Asphalt Additive
Advanced Materials Research, 2013
Going towards sustainable pavement construction, asphalt industries constantly give their effort to implement Warm Mix Asphalt (WMA) by adding the chemical warm asphalt additive (CWAA). This can lower its energy consumption and pollution by reducing the mixing and compaction temperatures of the asphalt mixture without affecting its properties. Several studies have been conducted evaluating the properties of the WMA, however, little documented research on the rheology of the binders containing CWAA is available especially when dealing the sources of binders. In this paper, the tests for rheology characteristics of the Malaysian asphalt binder containing CWAA were conducted with rotational viscosity and for dynamic mechanical analysis with dynamic shear rheometer (DSR). The results of the investigation indicated that the CWAA had a significant reduction of required heat for mixing and compaction effort and also shows lower permanent deformation when compared to the control binder.
P 5 EE-388 Mechanistic Properties of Warm MIX Asphalt Mixtures
2012
The past few years have seen the introduction of the warm mix asphalt (WMA) technology in efforts to reduce the required energy for the production and construction of asphalts. The basic principle of the WMA technology is to lower the mixing and compaction temperatures of the produce asphalt through lowering the viscosity-temperature relationship of the bitumen. The objective of this research effort was to evaluate the impact of WMA additives on the resistance of asphalts to moisture damage and permanent deformation. In addition, the low mixing temperature of WMA tends to leave access moisture inside the aggregates which is referred to as “residual moisture”. The study evaluated the impact of residual moisture in the aggregates and the interaction of WMA additives with polymer, recycled tire rubber, and anti-strip additives that are commonly to improve the long-term performance of asphalt pavements. The resistance of the mixtures to moisture damage was evaluated in terms of the impa...
Warm Mix Asphalt Technology: A Review
Jurnal Teknologi, 2014
Warm Mix Asphalt (WMA) represents the technologies that allow the reducing of asphalt binders' mixing and compaction temperatures by reducing its binders' viscosity. This paper gives a comprehensive chronological review from prior researches and practical experienced among researchers and industrial practitioners while implementing WMA technology including constituent materials, mix design and mechanical performance issues. Within this, the problems and benefits as well as different types of WMA additives were clearly identified as essential for a better understanding of the application of WMA technology in pavement constructions.
Density, Adhesion and Stiffness of Warm Mix Asphalts
Procedia - Social and Behavioral Sciences, 2014
This study presents the results of different laboratory tests related to the density, adhesion (sensitivity to water test) and rigidity (resilient module) of bituminous mixtures, manufactured at three different temperatures (160 °C, 140 °C and 120 °C), with three additives: a surfactant made up of different amino substances, a paraffin obtained by the Fisher-Tropsch synthesis process which is totally soluble in bitumen, and a synthetic zeolite in powder form which causes the bitumen to micro-foam,. Test samples have been compacted by impact, according to the Marshall method, and kneading, according to gyratory machine. To evaluate these properties an asphalt concrete mixture has been chosen, with a binder, B-50/70, and a maximum size of aggregates of 16 mm, which is usually placed in the surface layer of the pavement. The densities obtained by the two compaction methods are easy to reach. Densities will decrease if the temperature of manufacturing is lower. All mixtures compacted by gyratory machine at different temperatures displayed very good behavior of water sensitivity; but not all mixtures compacted by impact achieved this. The additives improve the adhesion between aggregate and binder. The stiffness moduli decreased in all mixtures for both types of compaction when the temperature was higher, and this reduction is less pronounced in the mixes manufactured with the gyratory compactor. Mixtures with additives tend to reduce the module, except paraffin.
Evaluation of polymer modified asphalts containing warm mix additives in rheology
WIT Transactions on the Built Environment, 2009
Polymer modified asphalt (PMA) binders can be utilized using warm mix asphalt (WMA) technologies in order to aim for the green highway construction by lowering construction temperatures and toxic by-products (i.e., CO 2 , smoke, and odor). This paper focused on a rheological investigation of three PMA binders, graded as PG 76-22, containing two warm additives (Aspha-min ® and Sasobit ®) available commercially. The main rheological factors selected in this study were relationships between loading and response as a function of time, temperature and frequency using a Bohlin Dynamic Shear Rheometer II. The results suggested that the two warm additives positively influenced the performance of PMA binders. In particular, the use of Sasobit ® showed the enhanced rutting resistance properties at high pavement temperature and more elastic properties at lower temperatures.