Morphological, Thermal, and Mechanical Properties of Asphalt Binders Modified by Graphene and Carbon Nanotube
Morphological, Thermal, and Mechanical Properties of Asphalt Binders Modified by Graphene and Carbon Nanotube
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DOI：
10.1061/(asce)mt.1943-5533.0004183
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发表时间：
2022-05-01
影响因子：
3.2
通讯作者：
Yin, Huiming
中科院分区：
文献类型：
--
作者：
Yu, Xiaokong;Zadshir, Mehdi;Yin, Huiming
沥青混凝土的力学性能随温度的变化而变化，因此，研究人员一直在开发减少路面加铺层温度波动的技术。提高沥青混凝土的导热系数是实现这些技术的关键。以前的研究已经在沥青结合料/混凝土中引入了碳纳米管(CNTs)、石墨、石墨烯纳米片(GNPs)和铜渣等添加剂，以提高其热物理性能。然而，评估这些添加剂在沥青材料中的分布一直是具有挑战性的。本文首先用表面活性剂对添加剂进行表面处理，然后用机械剪切混合机将粘结剂/碳纳米管和粘结剂/GNP混合到热粘结剂中，制备了二元(粘结剂/碳纳米管和粘结剂/GNP)和三元(粘结剂/碳纳米管/GNP)复合材料。利用数码显微镜和扫描电子显微镜对CNTs和GNPs在粘结剂中的形貌和分散均匀性进行了表征。采用纳米闪光和差示扫描量热仪相结合的方法测量了样品的导热系数。用流变仪测试了聚合物的流变性能。结果表明，我们的样品制备方法能够将碳纳米管和纳米颗粒均匀分散在粘结剂中，数字显微镜图像显示出比扫描电子显微镜更具代表性的沥青粘结剂的形貌。加入CNT(质量分数为0%~2%)和/或GNPs(质量分数为0%~15%)在一定程度上改善了粘结剂的导热性能，而CNT/GNP改性粘结剂的流变性能与对照样品非常接近。这项工作的发现可能会为开发新的沥青材料以及其他基于碳纳米管/GNP的复合材料提供一些启示。
The mechanical behavior of asphalt concrete varies with temperature; therefore, researchers have been developing technologies to reduce temperature fluctuations in pavement overlays. Increasing the thermal conductivity of asphalt concrete is a key component in the realization of these technologies. Previous studies have introduced, among other additives, carbon nanotubes (CNTs), graphite, graphene nanoplatelets (GNPs), and copper slag to asphalt binders/concrete to enhance their thermal-physical properties. However, it has been challenging to assess the distribution of these additives in asphalt materials. In this paper, binary (i.e., binder/CNT and binder/GNP) and ternary (i.e., binder/CNT/GNP) composites were prepared by pretreating the additives with a surfactant and through sonication, before they were mixed into the hot binder using a mechanical shear mixer. Morphology and dispersion uniformity of CNTs and GNPs in the binders were evaluated using a digital microscope and scanning electron microscopy (SEM). The thermal conductivity of these samples was measured using Nanoflash combined with differential scanning calorimetry. The rheological properties were tested using rheometry. Results showed that our sample preparation method was able to uniformly disperse the CNTs and GNPs in the binder, as seen in the digital microscope images that offered more representative morphologies of asphalt binders than SEM. The addition of CNTs (0%-2% by weight) and/or GNPs (0%-15% by weight) improved the binder's thermal conductivity at a limited degree, whereas the rheological properties of the CNT/GNP-modified binders remained very close to those of the control sample. Findings from this work may provide some insights into the development of new asphalt materials as well as other CNT/GNP-based composites.