Synthesis and characterization of multi-cavity Ca-alginate capsules used for self-healing in asphalt mixtures
Synthesis and characterization of multi-cavity Ca-alginate capsules used for self-healing in asphalt mixtures
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用于沥青混合料自修复的多腔海藻酸钙胶囊的合成与表征
DOI：
10.1016/j.conbuildmat.2019.03.224
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发表时间：
2019-06-30
影响因子：
7.4
通讯作者：
Shu, Benan
中科院分区：
文献类型：
--
作者：
Zhang, Lei;Liu, Quantao;Shu, Benan
本研究合成了不同水油比的向日葵籽油海藻酸钙胶囊，并对其物理性能、形态特征、热力学性能、含油量和拌和后的稳定性进行了研究，以筛选出最适合于沥青混合料的海藻酸钙胶囊。最后，将W/O比为10：1的海藻酸钙胶囊掺入沥青混合料中，通过三点弯曲试验研究了其在疲劳荷载下的油释放特性以及海藻酸钙胶囊对沥青混合料自愈合性能的影响。结果表明，2.5wt%海藻酸钠溶液能很好地包覆向日葵籽油，并与钙离子交换形成多腔胶囊。随着水油比的减小，多腔胶囊的尺寸增大。随着水油比的减小，沥青混合料拌和压实后胶囊的抗压强度、热稳定性和耐久性降低。认为W/O比为10：1的胶囊最适合于沥青混合料。在疲劳荷载作用下，向日葵籽油胶囊能够释放到沥青混合料中，并且随着疲劳荷载循环次数的增加，葵花籽油胶囊的释油率增加，从而导致沥青混合料的显著愈合。含有多腔胶囊的沥青混合料在疲劳载荷下可以达到高达180%的断裂能恢复，这意味着从胶囊中释放的油可以软化和再生沥青混合料。(C)2019爱思唯尔有限公司版权所有。
In this research, Ca-alginate capsules containing sunflower oil with different water/oil (W/O) ratios were synthesized and their physical properties, morphological characteristics, thermodynamic performance, oil content and survivability after mixing and compaction were studied to select the most suitable capsule for asphalt mixture. Finally, the capsules with a W/O ratio of 10:1 were incorporated into asphalt mixtures to investigate their oil release characteristics under fatigue loading and the effect of the multi-cavity Ca-alginate capsules on the self-healing properties of asphalt mixtures through threepoint bending test. It was found that 2.5 wt% sodium alginate solution can well encapsulate sunflower oil and exchange with Ca2+ to form multi-cavity capsules. The sizes of the multi-cavity capsules increase with the decrease of W/O ratio. The compressive strength, thermal stability and survivability of the capsules after the mixing and compaction of asphalt mixture decrease with the decrease of W/O ratio. It is believed that the capsules fabricated with a W/O ratio of 10:1 are most suitable for asphalt mixture. The capsules can release the sunflower oil into asphalt mixtures under fatigue loading and the oil release ratio increases with the increase of the cycles of fatigue loading, leading to a significant healing of asphalt mixture. Asphalt mixture containing multi-cavity capsules can reach up to 180% recovery of the fracture energy under fatigue loading, which means that the oil released from the capsules can soften and rejuvenate asphalt mixture. (C) 2019 Elsevier Ltd. All rights reserved.