scholarly journals Study on adaptability of rheological index of nano-PUA-modified asphalt based on geometric parameters of parallel plate

2021 ◽  
Vol 10 (1) ◽  
pp. 1801-1811
Author(s):  
Xiaolong Sun ◽  
Yikang Zhang ◽  
Qinyuan Peng ◽  
Junshen Yuan ◽  
Zhi Cang ◽  
...  

Abstract To clarify the influence of geometric parameters of parallel plate on rheological properties of polyurea elastomer (PUA)-modified asphalt, nano-PUA powder was prepared, and nano-PUA powder modifier was modified by using high-speed shearing apparatus. The apparent viscosity of modified asphalt was evaluated by Brookfield viscosity. The rheological parameters of PUA-modified asphalt were determined by comparing the rheological test results of temperature scanning, frequency scanning, and multiple stress creep recover test using 8 and 25 mm parallel plates. Results indicated that the higher the content of nano-PUA modifier was, the better the high-temperature performance of asphalt would be. When using the 8 mm parallel plate, the high-temperature performance of modified asphalt was worse than that of matrix asphalt, and the PUA modifier would lead to a negative effect on the rheological property of asphalt. Regarding the 25 mm parallel plate, the high-temperature performance of modified asphalt was better than that of matrix asphalt, which was contrary to the results of 8 mm parallel plate. The rheological test results using 25 mm parallel plate were consistent with the results of Brookfield viscosity, indicating that 25 mm parallel plate was more suitable for evaluating the rheological performance of PUA-modified asphalt.

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247390
Author(s):  
Xinli Gan ◽  
Wenli Zhang

The objective of this study is to verify the feasibility of using biochar made from crop straw as a bitumen additive to improve some properties of bitumen. The differences between crop straw biochar prepared in a laboratory and commercial charcoal were investigated through scanning electron microscopy and laser particle size analyses. Furthermore, biochar-modified asphalt was prepared using the high-speed shear method, and the penetration, softening point, ductility at 15°C, and apparent viscosity of the asphalt binder with 6% biochar were measured at 120, 135, 150, 160, and 175°C. It was found that both the crop straw biochar and the commercial charcoal consist mainly of C, O, Si, and K, but the C content of crop straw biochar is slightly higher than that of commercial charcoal. The particle size of biochar is smaller than that of commercial charcoal, while the specific surface area is larger. It was determined that the addition of crop straw biochar significantly improved the high-temperature performance of asphalt, and that biochar and commercial charcoal have a similar influence on the high temperature performance of asphalt.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4910
Author(s):  
Ping Zhang ◽  
Lan Ouyang ◽  
Lvzhen Yang ◽  
Yi Yang ◽  
Guofeng Lu ◽  
...  

As environmentally friendly materials, carbon black and bio-oil can be used as modifiers to effectively enhance the poor high-temperature and low-temperature performance of base asphalt and its mixture. Different carbon black and bio-oil contents and shear time were selected as the test influencing factors in this work. Based on the Box–Behnken design (BBD), carbon black/bio-oil composite modified asphalt was prepared to perform the softening point, penetration, multiple stress creep and recovery (MSCR), and bending beam rheometer (BBR) tests. The response surface method (RSM) was used to analyze the test results. In addition, the base asphalt mixtures and the optimal performance carbon black/bio-oil composite modified asphalt mixtures were formed for rutting and low-temperature splitting tests. The results show that incorporating carbon black can enhance the asphalt’s high-temperature performance by the test results of irrecoverable creep compliance (Jnr) and strain recovery rate (R). By contrast, the stiffness modulus (S) and creep rate (M) test results show that bio-oil can enhance the asphalt’s low-temperature performance. The quadratic function models between the performance indicators of carbon black/bio-oil composite modified asphalt and the test influencing factors were established based on the RSM. The optimal performance modified asphalt mixture’s carbon black and bio-oil content was 15.05% and 9.631%, and the shear time was 62.667 min. It was revealed that the high-temperature stability and low-temperature crack resistance of the carbon black/bio-oil composite modified asphalt mixture were better than that of the base asphalt mixture because of its higher dynamic stability (DS) and toughness. Therefore, carbon black/bio-oil composite modified asphalt mixture can be used as a new type of choice for road construction materials, which is in line with green development.


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.


2015 ◽  
Vol 744-746 ◽  
pp. 1316-1319
Author(s):  
Yi Wang ◽  
Wei Li

In order to deeply reveal the high temperature stability of asphalt mixture, rutting test was implemented to evaluate the high temperature stability of asphalt mixture, and the evaluation index is dynamic stability. The effect of asphalt type, degree of compaction, gradation type and nominal maximum aggregate size on rutting test results was studied respectively. The results showed that: modified asphalt can improve the high temperature stability of asphalt mixture effectively; the anti-rutting performance of asphalt mixture reduces gradually with decrease of the degree of compaction; the anti-rutting performance of SAC-16 is greater than that of AC-16; and the anti-rutting performance of asphalt mixture is improved with increase of the nominal size of aggregate.


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.


Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  

Abstract ALX is a composition of nonferrous materials with a cobalt base containing chromium, tungsten and carbon. This alloy is commonly supplied in the cast-to-shape form, having an as-cast hardness of Rockwell C60-62 and requiring no further heat treatment. ALX is also supplied as cast tool bit material and is useful where conventional high-speed steels or carbides do not function effectively. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, and machining. Filing Code: Co-35. Producer or source: Allegheny Ludlum Corporation.


Alloy Digest ◽  
1978 ◽  
Vol 27 (7) ◽  

Abstract CYCLOPS M4 is a deep-hardening steel that was developed to utilize the excellent abrasion resistance that results from higher-than-normal carbon and vanadium contents in the molybdenum-tungsten family of high-speed steels. It is recommended for heavy-duty cutting operations and for sharp edges for fine cuts. Cyclops M4 should always be used at or near maximum hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-335. Producer or source: Cyclops Corporation.


Alloy Digest ◽  
2001 ◽  
Vol 50 (10) ◽  

Abstract CPM Rex 121 is a super high-speed steel with significantly higher wear resistance and red hardness than other high-speed steels. It is best suited for applications requiring high cutting speeds. It may provide an alternative to carbide where carbide cutting edges are too fragile. The annealed hardness is approximately 350-400 HB, and maximum hardness is approximately 72 HRC. This datasheet provides information on composition, physical properties, microstructure, hardness, and elasticity as well as fracture toughness. It also includes information on high temperature performance and wear resistance as well as heat treating and surface treatment. Filing Code: TS-591. Producer or source: Crucible.


Alloy Digest ◽  
2019 ◽  
Vol 68 (11) ◽  

Abstract YSS YXM4 is a cobalt-alloyed molybdenum high-speed tool steel with resistance to abrasion, seizure, and deformation under high pressure. This datasheet provides information on composition, physical properties, and hardness. It also includes information on high temperature performance. Filing Code: TS-780. Producer or source: Hitachi Metals America, Ltd.


Alloy Digest ◽  
2019 ◽  
Vol 68 (10) ◽  

Abstract YSS HAP72 is a powder metallurgy high-speed tool steel with a very high wear resistance. This datasheet provides information on composition, hardness, and bend strength. It also includes information on high temperature performance. Filing Code: TS-779. Producer or source: Hitachi Metals America Ltd.


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