Influence of Different Types of Emulsifiers on Properties of Emulsified Asphalt Binder and Its Evaporation Residue by Molecular Dynamics Simulation

There is an important role in the properties of emulsified asphalt binder and its evaporation residue about emulsifier, which has been confirmed by experiment and chemical tests. However, there is little research about the emulsifier at microperspective. Therefore, the influence of two kinds of emulsifiers, a typical cationic emulsifier (dodecyl benzene sulfonate) and a typical anionic emulsifier (dodecyl primary amine), on technical properties of emulsified asphalt binder and its evaporation residues such as store stability, workability, breaking behavior, and mechanical properties are investigated using a microapproach. Results show that there is an effective role in the storage stability, workability, and demulsification of emulsified asphalt binder about cationic emulsifier compared with anionic emulsifier. The anionic emulsifier makes the density of evaporation residue larger. However, the mechanical properties of anionic emulsified asphalt evaporation residue are conversely smaller compared with the cationic emulsified asphalt evaporation residue. The adhesion behavior results have confirmed that the anionic emulsified asphalt evaporation residue has a negative adhesion with aggregate due to its anion. The mechanism of the different emulsifiers on asphalt binders and their evaporation residue is explored at a microscale to help us to understand emulsified asphalt binder and its evaporation residue more in depth.

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Kinetic Viscoelasticity of Crosslinking Epoxy Asphalt

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198119835530 ◽

2019 ◽

Vol 2673 (3) ◽

pp. 551-560 ◽

Cited By ~ 6

Author(s):

Panos Apostolidis ◽

Xueyan Liu ◽

Martin van de Ven ◽

Sandra Erkens ◽

Tom Scarpas

Keyword(s):

Mechanical Properties ◽

Asphalt Binder ◽

Crosslinking Density ◽

Asphalt Binders ◽

Experimental Program ◽

Model Parameters ◽

Epoxy Asphalt ◽

Pavement Structures ◽

Chemical Hardening ◽

Modified Binder

Epoxy modification of asphalt binders has been recognized as a very effective technology to alter the chemistry of asphaltic materials in such a way that long-lasting pavement structures can be designed. However, the phenomena that are involved to build up the physico-mechanical properties of epoxy asphalt systems are still unknown. The focus of this paper is on understanding the link between chemistry and the mechanical properties of epoxy asphalt binders during the thermo-irreversible process of chemical hardening. For this purpose, a constitutive model for predicting the evolution of cure-induced stresses in epoxy asphalt binders is proposed, and an experimental program was developed to determine the model parameters. The cure dependency of physico-mechanical parameters of modified binder was obtained and imported into the model to simulate the build-up of material properties during (non-)isothermal hardening of epoxy asphalt binder. The model is implemented in a commercially finite element tool by coupling the chemical, thermal, and mechanical phenomena with multi-physics strategies, and the results are analyzed to identify the influence of different heating conditions on the crosslinking density and subsequently on stress build-up. It was found that the amount of stress build-up during curing was strongly dependent on the heating conditions, and a higher rate of stress build-up was observed at higher applied temperatures. In other words, the processing conditions during in-plant material production or in-field manufacturing of structures made by epoxy asphalt systems affect the material hardening and subsequently the desired functionalities of pavement structures.

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Laboratory Evaluation of the Residue of Rubber-Modified Emulsified Asphalt

Sustainability ◽

10.3390/su12208383 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8383

Author(s):

Dongdong Ge ◽

Xiaodong Zhou ◽

Siyu Chen ◽

Dongzhao Jin ◽

Zhanping You

Keyword(s):

Chemical Change ◽

Asphalt Binder ◽

High Volume ◽

Crumb Rubber ◽

Asphalt Binders ◽

Laboratory Evaluation ◽

Chip Seal ◽

Improvement Effect ◽

Pavement Construction ◽

Emulsified Asphalt

Emulsified asphalt has been widely used in various surface treatment methods such as chip seal for low-volume road preservation. Using modified emulsified asphalt made it possible to use chip seal technology on medium- and even high-volume traffic pavements. The main objective of the study is to quantify the residue characteristics of rubber-modified emulsified asphalt and to assess the effectiveness of using crumb rubber to modify emulsified asphalt binder. The four emulsified asphalt residues used the distillation procedure. Then, the rheology characteristics of emulsified asphalt residue were evaluated. The Fourier transform infrared spectroscopy (FTIR) test analyzed the chemical change of emulsified asphalt during the aging procedure. The results indicate that the evaporation method cannot remove all the water in emulsified asphalt. The mass change during the rolling thin film oven (RTFO) process only represented the component change of emulsified asphalt binder residue. Both the high-temperature and low-temperature performance grade of the two emulsified asphalt binders with rubber were lower. The original asphalt binder adopted to emulsification had a crucial influence on the performance of emulsified asphalt. The rubber modification enhanced the property of the emulsified asphalt binder at low temperatures, and the improvement effect was enhanced as the rubber content in the emulsified asphalt was raised. The C=O band was more effective in quantifying the aging condition of the residue. The findings of this study may further advance the emulsified asphalt technology in pavement construction and maintenance.

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Enhancement of Asphalt Performance by Graphene-Based Bitumen Nanocomposites

10.31979/mti.2021.1918 ◽

2021 ◽

Author(s):

Sara Moghtadernejad ◽

Ehsan Barjasteh ◽

Ren Nagata ◽

Haia Malabeh

Keyword(s):

Mechanical Properties ◽

Experimental Evaluation ◽

Asphalt Binder ◽

Premature Aging ◽

Asphalt Binders ◽

Modified Asphalt ◽

Modified Asphalt Binder ◽

Graphene Nanoparticles ◽

Polymer Modified Asphalt ◽

Asphalt Performance

As the State of California continues to grow, demand for enhanced infrastructure such as roadways and highways escalates. In view of the current average highway lifespan of 15–20 years, the improvement of asphalt binders leads to material sustainability by decreasing required maintenance and increasing the lifespan of roadways. In the present investigation, enhancement of asphalt binder properties was achieved by different methods of mixing varying compositions of graphene nanoparticles with an SBS polymer and asphalt binder. Additionally, experimental evaluation and comparison of the rheological and mechanical properties of each specimen is presented. Graphene nanoparticles have attracted great curiosity in the field of highway materials due to their incredible rigidity, even in small quantities. Addition of as little as 1.0%nanoparticles in combination with polymers in an asphalt binder is expected to increase the rigidity of the material while also maintaining the beneficial polymer characteristics. Evaluation of the effect of the mixing design established that the methods for application of graphene to the polymer-modified asphalt binder are critical in the improvement of a roadway, resulting in resistance to premature aging and strain from constant road operation.

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Effects of microstructure and temperature on the mechanical properties of nanocrystalline CoCrFeMnNi high entropy alloy under nanoscratching using molecular dynamics simulation

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2021.159516 ◽

2021 ◽

Vol 871 ◽

pp. 159516

Author(s):

Yuming Qi ◽

Tengwu He ◽

Heming Xu ◽

Yandong Hu ◽

Miao Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Dynamics Simulation ◽

High Entropy Alloy ◽

High Entropy

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Material Properties and Environmental Benefits of Hot-Mix Asphalt Mixes Including Local Crumb Rubber Obtained from Scrap Tires

Environments ◽

10.3390/environments8060047 ◽

2021 ◽

Vol 8 (6) ◽

pp. 47

Author(s):

Lim Min Khiong ◽

Md. Safiuddin ◽

Mohammad Abdul Mannan ◽

Resdiansyah

Keyword(s):

Asphalt Binder ◽

Crumb Rubber ◽

Environmental Benefits ◽

Asphalt Binders ◽

Rubber Content ◽

Scrap Tires ◽

Asphalt Mixes ◽

Temperature Resistance ◽

Modified Asphalt ◽

Marshall Stability

This paper presents the results of a laboratory-based experimental investigation on the properties of asphalt binder and hot-mix asphalt (HMA) mixes modified by locally available crumb rubber, which was used as a partial replacement of asphalt by weight. In this study, fine crumb rubber with a particle size in the range of 0.3–0.6 mm, obtained from scrap tires, was added to the asphalt binder through the wet process. Crumb rubber contents of 5%, 10%, 15%, and 19% by weight of asphalt were added to the virgin binder in order to prepare the modified asphalt binder samples, while the unmodified asphalt binder was used as the control sample. The crumb rubber modified binder samples were examined for measuring viscosity indirectly using the penetration test, and temperature resistance using the softening point test. Later, both the modified and unmodified asphalt binders were used to produce HMA mixes. Two categories of HMA mix commonly used in Malaysia—namely, AC 14 (dense-graded) and SMA 14 (gap-graded)—were produced using the modified asphalt binders containing 5%, 10%, 15%, and 19% crumb rubber. Two AC 14 and SMA 14 control mixes were also produced, incorporating the unmodified asphalt binder (0% crumb rubber). All of the AC 14 and SMA 14 asphalt mixes were examined in order to determine their volumetric properties, such as bulk density, voids in total mix (VTM), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). In addition, the Marshall stability, Marshall flow, and stiffness of all of the AC 14 and SMA 14 mixes were determined. Test results indicated that the modified asphalt binders possessed higher viscosity and temperature resistance than the unmodified asphalt binder. The viscosity and temperature resistance of the asphalt binders increased with the increase in their crumb rubber content. The increased crumb rubber content also led to improvements in the volumetric properties (bulk density, VTM, VMA, and VFA) of the AC 14 and SMA 14 mixes. In addition, the performance characteristics of the AC 14 and SMA 14 mixes—such as Marshall stability, Marshall flow, and stiffness—increased with the increase in crumb rubber content. However, the AC 14 mixes performed much better than the SMA 14 mixes. The overall research findings suggest that crumb rubber can be used to produce durable and sustainable HMA mixes, with manifold environmental benefits, for use in flexible pavements carrying the heavy traffic load of highways.

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Mechanical properties of Fe, Ni and Fe-Ni alloy: Strength and stiffness of materials using lammps molecular dynamics simulation

10.1063/5.0034046 ◽

2020 ◽

Author(s):

Arief Maulana ◽

Artoto Arkundato ◽

Sutisna ◽

Herri Trilaksana

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Dynamics Simulation ◽

Ni Alloy ◽

Alloy Strength ◽

Strength And Stiffness

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Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

International Journal of Pavement Research and Technology ◽

10.1007/s42947-020-6008-3 ◽

2020 ◽

Vol 13 (6) ◽

pp. 697-706

Author(s):

Yuhong Wang ◽

Kecheng Zhao ◽

Fangjin Li ◽

Qi Gao ◽

King Wai Chiu Lai

Keyword(s):

Near Field ◽

Asphalt Binder ◽

Optical Microscope ◽

Asphalt Binders ◽

Zero Shear Viscosity ◽

Surface Features ◽

Asphaltene Content ◽

Scanning Transmission ◽

Before And After ◽

Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

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Determination of mechanical properties of two-phase and hybrid nanocomposites: experimental determination and multiscale modeling

Journal of Polymer Engineering ◽

10.1515/polyeng-2020-0312 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mahmoud Haghighi ◽

Hossein Golestanian ◽

Farshid Aghadavoudi

Keyword(s):

Mechanical Properties ◽

Ultimate Strength ◽

Multiscale Modeling ◽

Filler Content ◽

Hybrid Nanocomposites ◽

Dynamics Simulation ◽

Strength Increase ◽

Two Phase ◽

Macro Scale ◽

Elongation To Failure

Abstract In this paper, the effects of filler content and the use of hybrid nanofillers on agglomeration and nanocomposite mechanical properties such as elastic moduli, ultimate strength and elongation to failure are investigated experimentally. In addition, thermoset epoxy-based two-phase and hybrid nanocomposites are simulated using multiscale modeling techniques. First, molecular dynamics simulation is carried out at nanoscale considering the interphase. Next, finite element method and micromechanical modeling are used for micro and macro scale modeling of nanocomposites. Nanocomposite samples containing carbon nanotubes, graphene nanoplatelets, and hybrid nanofillers with different filler contents are prepared and are tested. Also, field emission scanning electron microscopy is used to take micrographs from samples’ fracture surfaces. The results indicate that in two-phase nanocomposites, elastic modulus and ultimate strength increase while nanocomposite elongation to failure decreases with reinforcement weight fraction. In addition, nanofiller agglomeration occurred at high nanofiller contents especially higher than 0.75 wt% in the two-phase nanocomposites. Nanofiller agglomeration was observed to be much lower in the hybrid nanocomposite samples. Therefore, using hybrid nanofillers delays/prevents agglomeration and improves mechanical properties of nanocomposite at the same total filler content.

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