Dielectric loss law of asphalt mixture under the condition of microwave heating

2014 ◽  
Vol 46 (1) ◽  
pp. 313-323 ◽  
Author(s):  
Tongsheng Sun
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yongfeng Wei ◽  
Jinyang Huo ◽  
Zhenjun Wang ◽  
Jiangtao Gao

Emulsified asphalt needs to be cured for a certain age after demulsification to produce strength, which seriously affects the traffic opening time. In this work, microwave heating technology was applied for emulsified asphalt repair materials. Steel slag with high microwave activity was adopted to improve the performance of emulsified asphalt repair materials by microwave heating. Effects of steel slag sizes and contents on the heating rate, temperature distribution, and thermal performance of emulsified asphalt repair materials were analyzed by close microwave heating, open microwave heating, and repair simulation tests. Results show that the temperature of emulsified asphalt repair materials presents three different heating stages under microwave irradiation. The “critical point of phase transition” in the three stages is gradually advanced with the increase in steel slag content. The core temperature and maximum temperature of emulsified asphalt repair materials with different steel slag sizes are basically the same; however, the heat distribution of emulsified asphalt repair materials is significantly different. In contrast to conventional asphalt mixture, there exists a smaller temperature difference. The temperature of repairing materials can reach above 80°C. The interface area can form an embedded interface structure. Incorporation of steel slag and adoption of microwave heating are effective to improve the performance of emulsified asphalt repair materials.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402199047
Author(s):  
Yanfang Song ◽  
Zhe Wang ◽  
Yan Zhou ◽  
Rong Hu

Aiming at the change law of the flexural and tensile strength of the modified steel slag asphalt mixture during microwave heating, the results of this paper are as follows: the microwave heating process can achieve the recovery of the flexural and tensile properties of the modified steel slag asphalt mixture. The number of point bending failure tests continues to increase, and the recovery rate of bending and tensile properties of beams made of modified steel slag asphalt mixture will slowly decrease until the test piece is completely destroyed. The flexural and tensile strength of beams made by microwave heating asphalt mixture cannot be fully recovered, but different asphalt mixtures have different recovery effects. Compared with the ordinary basalt asphalt mixture, the steel slag asphalt mixture before modification has the same bending and tensile repair effect after microwave heating, while the modified steel slag asphalt mixture has the first bending and tensile repair effect after microwave heating increased by 23%.


2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S342-S345
Author(s):  
L. M Guardeño ◽  
M. Hernández-Carrión ◽  
J. M Catala-Civera ◽  
P. Plaza ◽  
I. Pérez-Munuera ◽  
...  

The aim of this work was to improve microwave heating in white sauces using different polysaccharides in their formulation; &iota;-, &lambda;- and &kappa-carrageenan and native and modified starches were used as thickeners. Five model systems were prepared, each one with a different polysaccharide, salt, and water. Dielectric loss factor (&epsilon;'') was measured and penetration depth of the electric field was calculated at 20 and 40°C at 2450 GHz. The results showed that &epsilon;'' increased significantly (<I>P</I> < 0.05) when temperature rose in all the model systems. Moreover, &epsilon;'' decreased significantly (<I>P</I> < 0.05) when the polysaccharide concentration rose in the systems elaborated with starch (both native and modified). The penetration depth increased significantly at 40°C when native starch concentration rose. Not significant differences due to the thickener concentration were found in the depth penetration values in the other model systems, both at 20 and 40°C.


LWT ◽  
2019 ◽  
Vol 101 ◽  
pp. 559-566 ◽  
Author(s):  
Nana Zhang ◽  
Daming Fan ◽  
Yueliang Zhao ◽  
Yejun Wu ◽  
Bowen Yan ◽  
...  

2020 ◽  
Vol 10 (4) ◽  
pp. 1428 ◽  
Author(s):  
Federico Gulisano ◽  
João Crucho ◽  
Juan Gallego ◽  
Luis Picado-Santos

Pavement preventive maintenance is an important tool for extending the service life of the road pavements. Microwave heating seems to be a promising technology for this application, as bituminous materials have the potential to self-repair above a certain temperature. As ordinary asphalt mixture has low microwave absorbing properties, some additives should be used to improve the heating efficiency. In this paper, the effect of adding Electric Arc Furnace (EAF) slag and Graphene Nanoplatelets (GNPs) on the microwave heating and healing efficiency of asphalt mixtures was evaluated. Microwave heating efficiency was assessed by heating the specimens using several heating times. In addition, the electrical resistivity of the mixtures was measured to understand its possible relationship with the microwave heating process. Furthermore, the healing rates of the asphalt mixtures were assessed by repeated Indirect Tensile Strength (ITS) tests. The results obtained indicate that the additions of graphene and EAF slag can allow important savings, up to 50%, on the energy required to perform a good healing process.


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