海藻酸钙胶囊对老化沥青性能的影响研究

Effect of Calcium Alginate Capsules on the Performance of Aged Asphalt

添加胶囊以提高沥青混凝土自愈合能力已成为一个热门的研究方向,但是胶囊对老化沥青性能影响尚不明确.文中制备了一种毫米级的海藻酸钙胶囊,利用扫描电镜和拉力试验机研究了胶囊的形貌和强度,并将胶囊掺入沥青混合料分别进行短期热氧老化、长期热氧老化和紫外老化,然后利用万能试验机对小梁试件进行压缩试验,使胶囊在应力作用下释放其内部再生剂,并对抽提沥青进行流变性能试验,研究海藻酸钙胶囊对老化沥青性能的影响.结果表明:荷载作用下从胶囊内释放的再生剂,降低了老化沥青的复合剪切模量,增大了老化沥青的相位角,同时提高了老化沥青的蠕变性能,增强了沥青的形变恢复能力,证实海藻酸钙胶囊在荷载作用下释放的再生剂对老化沥青具有再生作用.

Adding capsules to improve the self-healing ability of asphalt concrete has become a hot research direction,but the effect of capsules on the performance of aged asphalt is unclear.A millimeter calcium alginate capsule was prepared.The morphology and strength of the capsules were studied by SEM and tensile testing machine,and the capsules were mixed into asphalt mixture for short-term thermal oxidation aging,long-term thermal oxidation aging and ultraviolet aging.Then,the trabecular specimen was compressed by universal testing machine,so that the capsule released its internal regenerant under stress.Finally,the rheological properties of extractable bitumen were tested to study the effect of calcium alginate capsules on the properties of aged asphalt.The results show that the regenerant released from the capsule under load reduces the composite shear modulus of aged asphalt and increases the phase angle of aged asphalt.Meanwhile,the creep property of aged asphalt is improved,and the deformation recovery ability of asphalt is enhanced,which proves that the regenerant released by calcium alginate capsules under load can regenerate aged asphalt.