Yu Xin, Liu Quantao, Wan Pei, Song Jiangkai, Wang Huan, Zhao Feiyang, Wang Yafei, Wu Jinyi
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
Materials (Basel). 2022 Feb 14;15(4):1414. doi: 10.3390/ma15041414.
Calcium alginate capsules within asphalt concrete can gradually release interior asphalt rejuvenator under cyclic loading to repair micro cracks and rejuvenate aged asphalt in-situ. However, asphalt pavement will become aged due to environmental and traffic factors during the service period. In view of this, this paper investigated the effect of ageing on the healing properties of asphalt concrete containing calcium alginate/attapulgite composite capsules under cyclic loading. The capsules were fabricated using the orifice-bath method and the morphological structure, mechanical strength, thermal stability, oil release ratios and healing levels of capsules in fresh, short-term ageing and long-term ageing asphalt concrete were explored. The results indicated that the different ageing treatments would not damage the multi-chamber structure nor decrease the mechanical strength of capsules but would induce the capsules release oil prematurely. The premature oil released from capsules in turn can offset the ageing effect owing to ageing treatment. The short-term ageing and long-term ageing plain asphalt mixtures gained strength recovery ratios of 39.3% and 34.2% after 64,000 cycles of compression loading, while the strength recovery ratios of short-term ageing and long-term ageing asphalt mixtures containing capsules were 63.5% and 54.8%, respectively.
沥青混凝土中的海藻酸钙胶囊在循环荷载作用下可逐渐释放内部的沥青再生剂，以修复微裂缝并就地恢复老化沥青的性能。然而，在服役期间，由于环境和交通因素，沥青路面会逐渐老化。鉴于此，本文研究了老化对含海藻酸钙/凹凸棒石复合胶囊的沥青混凝土在循环荷载作用下愈合性能的影响。采用孔浴法制备胶囊，并探究了新鲜、短期老化和长期老化沥青混凝土中胶囊的形态结构、机械强度、热稳定性、释油率和愈合程度。结果表明，不同的老化处理不会破坏胶囊的多腔结构，也不会降低其机械强度，但会导致胶囊过早释油。胶囊过早释放的油反过来可以抵消老化处理带来的老化效应。短期老化和长期老化的普通沥青混合料在经过64000次压缩加载循环后，强度恢复率分别为39.3%和34.2%，而含胶囊的短期老化和长期老化沥青混合料的强度恢复率分别为63.5%和54.8%。
