Effect of surfacemodified fly ash on engineering performance of asphalt(PDF)
长安大学学报(自然科学版)[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2018年03期
- Page:
- 34-42
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Effect of surfacemodified fly ash on engineering performance of asphalt
- Author(s):
- ZHANG Baolong; WU Ping; YAN Xinyong; WANG Yulan; NIU Dongyu
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- Keywords:
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- PACS:
- -
- DOI:
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- Abstract:
- This study aims to determine the interaction between fly ash and asphalt. The surfacemodification technology was adopted, and four kinds of fly ash from different sources were treated with NaOH solution and KH550 coupling agent. Subsequently, the dynamic shear and bending beam rheological tests were used to assess the highand lowtemperature properties of the fly ash asphalt mortar under different surfacemodification techniques. Finally, the modification mechanism owing to fly ash was studied using Xray diffraction, the BrunauerEmmettTeller (BET) adsorption test, and infrared spectroscopy. The results show that with the exception of some individual samples, NaOH and KH550 modified fly ash reduce the elasticity of asphalt mortar, and improve its rutting resistance. After NaOH modification, the lowtemperature crack resistance of FA3 asphalt mortar is found to be the worst, the FA4 asphalt mortar exhibit the best anticracking performance at low temperature. There is no obvious chemical reaction between the fly ash and the asphalt after KH550 coupling agent modification, but there is also no evidence to indicate that there is no slight chemical coupling interaction between KH550, fly ash, and asphalt. There is no new phase separation after NaOH treatment, however, NaOH modify the surface of the superfine powder with more active points, i.e., the specific surface area and volume fraction is enhanced by the NaOH solution. This surfacemodification effect is more obvious than that of KH550. The findings in this article indicated that as a filler, modified fly ash can effectively improve the road performance of asphalt concrete as well as provide a guidance for the reuse of fly ash. 3 tabs, 10 figs, 29 refs.
Last Update: 2018-06-13