Study on Influence of Snowmelt Agent to Performances of Asphalt

2014 ◽  
Vol 960-961 ◽  
pp. 78-81
Author(s):  
Jin Yang ◽  
Li Xia Liu ◽  
Peng Fei Xiao

To study the influences of snowmelt agent to performances of asphalt,three snowmelt agents of NaCl,CaC12,CH3COONa·3H2O were used to make asphalt sample and experiments about performances of high temperature and low temperature of asphalt were done.The results indicated that: temperature sensibility of 90# asphalt was reduced, softening point was increased ,dynamic viscosity was increased and ductility was reduced after being dealedwith snowmelt agent; Residual penetration ratio and residual ductility were also reduced after being dealedwith snowmelt agent.

2011 ◽  
Vol 84-85 ◽  
pp. 662-666 ◽  
Author(s):  
Zeng Ping Zhang ◽  
Yong Wen ◽  
Jian Zhong Pei ◽  
Shuan Fa Chen

Montmorillonite (MMT) modified asphalts are prepared by melt blending with the help of high-speed shear mixer. The dispersion of MMT layers in the asphalt matrix are characterized by X-ray diffraction (XRD). The effect of different contents of MMT on physical properties of the base asphalt is studied. These properties include penetration, softening point and ductility. The results indicate that MMT/asphalt may form a nanocomposite structure with MMT layers intercalated by the asphalt molecules. MMT can improve the high temperature performance and temperature sensitivity of the base asphalt. And it can slightly reduce the low temperature performances of matrix asphalt. It is found that low temperature performances, high temperature performance and temperature sensitivity of the modified system achieved balance when the content of MMT is 4 wt%.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6229
Author(s):  
Krzysztof Maciejewski ◽  
Piotr Ramiączek ◽  
Eva Remisova

The presented study explores the effects of decreased temperatures utilized in rolling thin-film oven (RTFOT) laboratory short-term ageing of asphalt binders based on 35/50- and 50/70-penetration paving-grade bitumen. Additionally, the effects of three additives used with these binders at different concentrations are evaluated: liquid anti-stripping agent, liquid warm-mix additive, and solid warm-mix additive. The resulting asphalt binders were subjected to basic (penetration at 25 °C, softening point, dynamic viscosity) and functional high-temperature characterization (G*/sin(δ), high critical temperature, non-recoverable creep compliance). It was found that the decreased short-term ageing temperatures may detrimentally impact the high-temperature grade of bituminous binders, but this effect can be mitigated by the use of appropriate additives. What is more, it was found that bituminous binders may respond differently to the aforementioned factors. Based on the results, it is advised that asphalt binders intended for use in warm-mix asphalts should be thoroughly tested to appropriately simulate the mixture production process and its effects.


2013 ◽  
Vol 405-408 ◽  
pp. 1753-1756
Author(s):  
Yong Mei Guo ◽  
Wei Chen

Six kinds of TOR rubber asphalts with 5%-30% rubber powder contents of were selected to carry out conventional high-temperature tests and dynamic shear rheological tests to obtain some parameters reflecting the high-temperature performance of asphalt binders, such as softening point, dynamic viscosity at 60°C, rutting factor (G*/sinδ) at 60°C and critical temperature of rutting factor (TG*/sinδ). The results show that the changing tendency of two rheological parameters of TOR rubber asphalts, G*/sinδ at 60°C and TG*/sinδ, is ascend in first and descend at last with the increase of rubber powder content proportion. The high-temperature performance of TOR rubber asphalt with the rubber powder content about 20% is the best. Softening point and dynamic viscosity at 60°C, as two conventional high-temperature parameters of asphalt binders, can describe the high-temperature performance of TOR rubber asphalt with the rubber powder content below 20%, but cannot evaluate accurately the high-temperature performance of TOR rubber asphalt with the rubber powder content above 20%, because TOR rubber asphalt has formed a network structure at this moment.


2021 ◽  
Vol 11 (9) ◽  
pp. 1579-1586
Author(s):  
Zixuan Chen ◽  
Xudong Li ◽  
Jie Xie ◽  
Jianzhong Pei ◽  
Chengchao Wang ◽  
...  

Reduced graphene oxide (RGO) was self-prepared by the oxidation reduction method and then characterized by several tests known as Fourier Transform Infrared Spectroscopy (FTIR) test, scanning electron microscopy (SEM) test, transmission electron microscopy (TEM) test, elemental analysis, raman measurement and thermogravimetry (TG) analysis to evaluate the properties of RGO. Additionally, RGO modified asphalt was prepared in this research to study the influence of RGO on matrix asphalt. Some of the normal performances of RGO modified asphalt were studied in terms of penetration at medium temperature, penetration index (PI), softening point, equivalent softening point T800 at high temperature and ductility at low temperature. Results showed that the prepared RGO has obvious layer structures and good properties and the performance of RGO modified asphalt at high temperature has increased significantly while the performance at low temperature decreased slightly. This research can provide an insight for the further study of RGO modified asphalt to enhance its road performance.


Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


2020 ◽  
Vol 10 (10) ◽  
pp. 59-67
Author(s):  
Victor N. ANTIPOV ◽  
◽  
Andrey D. GROZOV ◽  
Anna V. IVANOVA ◽  
◽  
...  

The overall dimensions and mass of wind power units with capacities larger than 10 MW can be improved and their cost can be decreased by developing and constructing superconducting synchronous generators. The article analyzes foreign conceptual designs of superconducting synchronous generators based on different principles: with the use of high- and low-temperature superconductivity, fully superconducting or only with a superconducting excitation system, and with the use of different materials (MgB2, Bi2223, YBCO). A high cost of superconducting materials is the main factor impeding commercial application of superconducting generators. In view of the state of the art in the technology for manufacturing superconductors and their cost, a conclusion is drawn, according to which a synchronous gearless superconducting wind generator with a capacity of 10 MW with the field winding made of a high-temperature superconducting material (MgB2, Bi-2223 or YBCO) with the «ferromagnetic stator — ferromagnetic rotor» topology, with the stator diameter equal to 7—9 m, and with the number of poles equal to 32—40 has prospects for its practical use in the nearest future.


Alloy Digest ◽  
1980 ◽  
Vol 29 (12) ◽  

Abstract SOMERS LTA Copper is a wrought copper foil that can be annealed at 350 F in 15 minutes to the full-soft condition; its use simplifies the manufacture of printed circuits (LTA = Low-Temperature Annealable). LTA Copper is especially useful for foil weights up to and including one ounce per square foot (0.0014-inch thick) for laminating to high-temperature dielectric substrates. This datasheet provides information on composition, physical properties, and elasticity as well as fatigue. It also includes information on forming, heat treating, and machining. Filing Code: Cu-407. Producer or source: Olin Corporation.


Alloy Digest ◽  
1958 ◽  
Vol 7 (2) ◽  

Abstract CHRO-MOW is a tough hot work steel which will harden from a relatively low temperature in air. It possesses a desirable combination of toughness and red-hardness. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-67. Producer or source: Crucible Steel Company of America.


Alloy Digest ◽  
1960 ◽  
Vol 9 (3) ◽  

Abstract NICLOY 5 is a low carbon, nickel ferritic steel reecommended for low temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-96. Producer or source: Babcock & Wilcox Company.


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