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Shu Wei Goh Michelle Akin Zhanping You Xianming Shi 《Construction and Building Materials》2011,25(1):195-200
This paper reports on the potential benefits of micro- or nano-sized materials for asphalt mixtures used on pavements, specifically when they are exposed to water or deicing solutions. Asphalt mixtures were prepared with various amount of nanoclay and/or carbon microfiber, and compacted using the Superpave? gyratory compactor. Moisture susceptibility and deicer impacts were assessed by exposing the samples to water or deicing chemicals (NaCl, MgCl2 and CaCl2), and seven freeze–thaw cycles, in a modified AASHTO T283 test. Comparisons of micro- or nano-modified asphalt mixtures exposed to deicers are made based on results of indirect tensile strength tests, which preliminarily demonstrate the great potential of using microfibers and nanoclays in asphalt mixture for improved performance. Based on the results, it was found that the addition of nanoclay and carbon microfiber would improve a mixture’s moisture susceptibility performance or decrease the moisture damage potential in most cases. The detailed effects of deicing solutions on the tensile strength of micro- or nano- modified asphalt mixture are discussed in this paper. 相似文献
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Zhanping You Julian Mills-Beale Justin M. Foley Samit Roy Gregory M. Odegard Qingli Dai Shu Wei Goh 《Construction and Building Materials》2011,25(2):1072-1078
The objective of this study is to review existing literature in the area of nano-modification of asphalt and proceed to apply nano-materials to asphalt to improve the performance. This study integrates literature review, preparation, and characterization of nano-modified asphalt materials. In the experimental testing montmorillonite, nanoclay at 2% and 4% by weight of asphalt was blended in asphalt binder at a high temperature to exfoliate the nanoclay within the asphalt. The asphalt binder was then characterized using the Superpave? rotational viscosity, dynamic shear modulus, and direct tension test. The rotational viscosity results indicate that the addition of the two types of nanoclay, Nanoclay A and Nanoclay B, increased the rotational viscosity by an average of 41% and 112%, respectively, across test temperatures 80, 100, 130, 135, 150 and 175 °C. It was found that the dynamic shear complex modulus (G*) value increases significantly across a range of testing temperatures (from 13 to 70 °C) and loading frequencies (0.01–25 Hz). With 2% Nanoclay A reinforcement in the asphalt binder, the complex shear moduli generally increased by 66% while the 4% Nanoclay A reinforcement in the asphalt binder generally increased the shear complex moduli by 125%. The 2% and 4% Nanoclay B increased the shear complex moduli by 184% and 196%, respectively. In terms of direct tension strength, the use of Nanoclay A and Nanoclay B reduced the strain failure rate of the original binder while the secant or direct tension moduli showed increase with the addition of the nanoclays. In furtherance of this research, nanoclay-modified asphalt is being tested at percentages higher than 4% to underscore the fact that nanoclays may have the potential to reduce rutting and cracking. 相似文献
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电流变体特性及电流变体应用器件的进展 总被引:2,自引:0,他引:2
本文详细评述了电流变体(ERF)材料的组成、工作机理及其流变力学性能,提出以Bingham塑性体来近似描述电流变体的流变特性,综述了电流变体在智能材料、汽车离合器、液压阀门等器件中的应用,给出了含电流变体的双层智能复合材料梁单层、双层加电状态对其振动特性的影响,设计了含电流变体的主动控制式减振器,并对其在外加电场作用下的减振性能进行了评价。 相似文献
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T. N. Goh 《Quality and Reliability Engineering International》2011,27(2):221-227
Six Sigma has enjoyed considerable popularity in the industry for about a quarter of a century. While the standard contents of Six Sigma have been described and discussed widely, some little articulated aspects of Six Sigma implementation deserve the attention of serious practitioners. In this paper, a ‘5W+1H’ (What, Why, When Where, Who, How) format is used to elucidate the nature of Six Sigma in a non‐mathematical discussion, followed by observations peculiar to the usual mode of development of Six Sigma professionals. It is pointed out that Six Sigma has Statistical Thinking as its foundation; for Six Sigma and its associated frameworks such as Design for Six Sigma and Lean Six Sigma to continue to be effective, it is important that users have a clear understanding of the nature of Six Sigma and be able to address the related challenges in practice. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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对作为冷轧窄钢带原料的65Mn宽钢带分条后容易产生开裂的原因进行分析,结果发现夹杂物级别高、中心偏析严重、组织不均匀是造成开裂的主要原因。通过优化工艺、提高材料内在质量,可以防止开裂。 相似文献
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Haitao Leng Yanping Chen Yunqing Huang 《Computers & Mathematics with Applications》2019,77(2):342-356
An elliptic optimal control problem involving the norm of the control in the cost functional is considered in this paper. We use the full discretization and the variational discretization to approximate the control problem and the efficient and reliable a posteriori error estimates are obtained for the two cases. For the variational discretization, we also analyze the convergence of adaptive finite element methods. In the end, some examples are provided to validate our analysis. 相似文献
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