scholarly journals Carbon Nanomaterials for Enhancing the Thermal, Physical and Rheological Properties of Asphalt Binders

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2585
Author(s):  
Zhelun Li ◽  
Xin Yu ◽  
Yangshi Liang ◽  
Shaopeng Wu

Effective thermal conduction modification in asphalt binders is beneficial to reducing pavement surface temperature and relieving the urban heat island (UHI) effect in the utilization of solar harvesting and snow melting pavements. This study investigated the performance of two nanometer-sized modifiers, graphene (Gr) and carbon nanotubes (CNTs), on enhancing the thermal, physical and rheological properties of asphalt binders. Measurements depending on a transient plant source method proved that both Gr and CNTs linearly increased the thermal conductivity and thermal diffusivity of asphalt binders, and while 5% Gr by volume of matrix asphalt contributed to 300% increments, 5% CNTs increased the two parameters of asphalt binders by nearly 72% at 20 °C. Meanwhile, a series of empirical and rheological properties experiments were conducted. The results demonstrated the temperature susceptibility reduction and high-temperature properties promotion of asphalt binders by adding Gr or CNTs. The variation trends in the anti-cracking properties of asphalt binders modified by Gr and CNTs with the modifier content differed at low temperatures, which may be due to the unique nature of Gr. In conclusion, Gr, whose optimal content is 3% by volume of matrix asphalt, provides superior application potential for solar harvesting and snow melting pavements in comparison to CNTs due to its comprehensive contributions to thermal properties, construction feasibility, high-temperature performance and low-temperature performance of asphalt binders.

2021 ◽  
Vol 13 (18) ◽  
pp. 10271
Author(s):  
Yuchen Guo ◽  
Xuancang Wang ◽  
Guanyu Ji ◽  
Yi Zhang ◽  
Hao Su ◽  
...  

The deteriorating ecological environment and the concept of sustainable development have highlighted the importance of waste reuse. This article investigates the performance changes resulting from the incorporation of shellac into asphalt binders. Seashell powder-modified asphalt was prepared with 5%, 10%, and 15% admixture using the high-speed shear method. The microstructure of the seashell powder was observed by scanning electron microscope test (SEM); the physical-phase analysis of the seashell powder was carried out using an X-ray diffraction (XRD) test; the surface characteristics and pore structure of shellac were analyzed by the specific surface area Brunauer-Emmett-Teller (BET) test; and Fourier infrared spectroscopy (FTIR) qualitatively analyzed the composition and changes of functional groups of seashell powder-modified asphalt. The conventional performance index of seashell powder asphalt was analyzed by penetration, softening point, and ductility (5 °C) tests; the effect of seashell powder on asphalt binder was studied using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR) at high and low temperatures, respectively. The results indicate the following: seashell powder is a coarse, porous, and angular CaCO3 bio-material; seashell powder and the asphalt binder represent a stable physical mixture of modified properties; seashell powder improves the consistency, hardness, and high-temperature performance of the asphalt binder but weakens the low-temperature performance of it; seashell powder enhances the elasticity, recovery performance, and permanent deformation resistance of asphalt binders and improves high-temperature rheological properties; finally, seashell powder has a minimal effect on the crack resistance of asphalt binders at very low temperatures. In summary, the use of waste seashells for recycling as bio-modifiers for asphalt binders is a practical approach.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3986
Author(s):  
Huan-Yun Zhou ◽  
Huai-Bing Dou ◽  
Xian-Hua Chen

Aiming to improve the comprehensive road performance of asphalt binders, especially the high-temperature performance, a novel asphalt binder was prepared by compounding high-quality and low-cost polyethylene (PE) with graphene (GNPs) using a high-speed shearing machine. The rheological properties and interaction mechanism of PE/GNPs composite modified asphalt were investigated using temperature sweep (TeS), multiple stress creep recovery (MSCR), linear amplitude sweep (LAS) and Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM). The experimental results demonstrated that GNPs and PE can synergistically improve the high-temperature performance of asphalt binders and enhance the rutting resistance of pavements; the pre-blended PE/GNPs masterbatch has good medium-temperature fatigue and low-temperature cracking resistance. Meanwhile, PE/GNPs dispersed uniformly in the asphalt matrix, and the microstructure and dispersion of premixed PE/GNPs masterbatch facilitated the asphalt modification. No new absorption peaks appeared in the FT-IR spectra of the composite modified asphalt, indicating that asphalt binders were physically modified with GNPs and PE. These findings may cast light on the feasibility of polyethylene/graphene composite for asphalt modification.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1145
Author(s):  
Wei Li ◽  
Sen Han ◽  
Xiaokang Fu ◽  
Ke Huang

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm−1 caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jiupeng Zhang ◽  
Guoqiang Liu ◽  
Li Xu ◽  
Jianzhong Pei

Sasobit additives with different dosages were added into 70# and 90# virgin asphalt binders to prepare WMA binders. The rheological properties, includingG∗andδ, were measured by using DSR at the temperature ranging from 46°C to 70°C, and the effects of temperature, additive dosage and aging onG∗/sin⁡δ, critical temperature, and H-T PG were investigated. The results indicate that WMA additive improvesG∗but reducesδ, and the improvement on 70# virgin binder is more significant.G∗/sin⁡δexponentially decreases with the increasing temperature but linearly increases with the increasing additive dosage. Aging effect weakens the interaction between binder and additive but significantly increases the binder’s viscosity; that is whyG∗/sin⁡δis higher after short-term aging. In addition, the critical temperature increases with the increasing additive dosage, and the additive dosage should be more than 3% and 5% to improve H-T PG by one grade for 70# and 90# virgin binder, respectively.


2013 ◽  
Vol 734-737 ◽  
pp. 2287-2291 ◽  
Author(s):  
De Dong Guo

Fiber asphalt concrete has been more and more widely used in highway construction. For analyzing high and low temperature performance of fiber asphalt mixture, rheological properties of fiber asphalt mortar were studied through indoor test. Impact of Rheological properties of the fiber asphalt mortar on high temperature and low temperature properties of asphalt mixture was analyzed. Results showed that the larger fiber content was, the better performance of asphalt mixture's high temperature stability, fiber asphalt mortar rut factor and rutting tests results of asphalt mixture were linear correlation, reflecting the high temperature performance of asphalt mixture; With the increase of fiber content, variation of stiffness modulus, creep rate indicators and mixture low temperature performance was consistent, and rheological properties of fiber asphalt mortar could characterize low temperature performance of asphalt mixture.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jian Xu ◽  
Yan Gong ◽  
Li-Biao Chen ◽  
Tao Ma ◽  
Jun-Cheng Zeng ◽  
...  

Aiming to evaluate the high-temperature performance of asphalt binders and asphalt mixtures and to investigate the reliability of the standard technical indexes to evaluate the performance of the asphalt, six typically used asphalt types were employed in this study. The standard high-temperature rheological test, the multiple stress creep recovery (MSCR) test, and the zero-shear viscosity (ZSV) test were employed to characterize the high-temperature performance and non-Newtonian fluid properties of the asphalt. Meanwhile, the high-temperature performance of the asphalt mixture was evaluated through the rutting tests based on the mixture design of AC-13. In general, the modified asphalt performed better than the unmodified asphalt according to the high-temperature rheological properties tests. The ranking of the six kinds of asphalt was confirmed to be different in various laboratory tests. The test results of the asphalt binders showed that the Tafpack Super- (TPS-) modified asphalt performed best in the MSCR and ZSV tests, while the low-grade asphalt PEN20 had the best technical indexes in the dynamic shear rheometer (DSR) test. Besides, the relation between the asphalt and the asphalt mixture was analyzed by gray relational analysis (GRA) method. The present rutting indicator G ∗ / sin   δ  and  G ∗ / 1 − sin   δ ⋅   tan   δ − 1 for evaluating the asphalt mixtures’ high-temperature performance might no longer be suitable. The Cross/Williamson model was the most suitable for calculating and fitting the ZSV, which could be used as the key indicator of the high-temperature performance evaluation of the asphalt. This work lays a foundation for the further study of the high-temperature performance evaluation of asphalt binders.


2019 ◽  
Vol 46 (5) ◽  
pp. 403-412 ◽  
Author(s):  
Jun Cai ◽  
Yansong Wang ◽  
Di Wang ◽  
Rui Li ◽  
Jiupeng Zhang ◽  
...  

This study reviewed and compared the test methods for the high-temperature performance of asphalt binder, and selected repeated creep recovery (RCR) test to evaluate the high-temperature performance of three waste-based high-viscosity asphalt binders (WHABs, including D-I, D-II, and F) and a control sample (Tafpack-Super modified asphalt, TMA). Meanwhile, shear stress, test temperature, and aging degree of binders, which could influence high-temperature behavior of binders, were also investigated, and related evaluation indexes including recovery compliance (R), non-recoverable creep compliance (Jnr), and viscous stiffness modulus (Gv) were compared. Results show that WHABs has much better high-temperature performance than TMA; shear stress has the most prominent effect on binders’ high-temperature performance, followed by aging degree, and lastly the selected test temperature in γ–time curve results; R, Jnr, and Gv values results indicate aging degree has a significant effect on binders, and improving binders’ aging performance can greatly improve the high-temperature performance.


Sign in / Sign up

Export Citation Format

Share Document