Abstract: The preparation method of calcium alginate capsule needs to be optimized, hence the effects of preparation parameters such as sodium alginate solution concentration, emulsification shear rate and oil-water ratio on the particle size, yield strength and repair agent content of calcium alginate capsules were studied. The preparation parameters of calcium alginate capsules were optimized, and their repair effect of asphalt concrete was explored. The research results show that the optimum preparation parameters of calcium alginate capsules are sodium alginate solution with concentration of 2.0%, emulsification shear rate of 5000r/min and oil-water ratio of 1:10. The particle size of calcium alginate capsule prepared by the optimum preparation parameters is 2.16 mm, the yield strength is 13.23 n, and the content of repair agent is 76.03%. After the proposed capsule is mixed with asphalt concrete, it can gradually release the repair agent under cyclic load, so as to soften the asphalt and significantly improve the self-healing performance of asphalt concrete.

Key words: higheay engineering; asphalt concrete; self-healing; sustained release capsule; calcium alginate

摘要： 针对海藻酸钙胶囊的制备方法优化问题，研究了海藻酸钠溶液浓度、乳化剪切速率和油水比等制备参数对海藻酸钙胶囊的粒径、屈服强度和修复剂含量的影响规律，优化了海藻酸钙胶囊的制备参数，并探究了其对沥青混凝土的修复效果。研究结果表明：海藻酸钙胶囊的最佳制备参数为2.0%浓度分数的海藻酸钠溶液、5 000 r/min的乳化剪切速率和1∶10的油水比；采用最佳制备参数合成的海藻酸钙胶囊粒径为2.16 mm、屈服强度为13.23 N、修复剂含量为76.03%；该胶囊掺入沥青混凝土后能够在循环荷载作用逐渐释放修复剂，从而软化沥青、显著提升沥青混凝土的自愈合性能。

关键词: 道路工程；沥青混凝土；自愈合；缓释型胶囊；海藻酸钙