学术论文

      自愈合行为对水泥基复合材料力学性能恢复的影响

      Effect of self-healing behavior on recovery of mechanical properties of engineered cementitious composites

      摘要:
      为了研究自愈合行为对高掺量粉煤灰工程水泥基复合材料(ECC)力学性能恢复的影响,提出了一种利用共振频率表征混凝土材料内部健康/损坏状况的测量方法.通过共振频率测试、单轴拉伸实验和光学显微镜获取了ECC的共振频率、刚度、初始开裂强度、最大拉伸应变和裂缝形态.实验结果表明:经过15个干湿循环养护后,共振频率可恢复程度都可达到82%以上;预裂ECC的二次拉伸性能有着明显的恢复,重新出现了初始开裂阶段;刚度的恢复程度可达到58%以上,最大拉伸应变恢复程度在90%以上;自愈合作用可以使得一部分自愈合裂缝的开裂强度大于基质开裂强度.研究表明,利用高掺量粉煤灰材料制备高延性、高自愈合的ECC是可行的.
      Abstract:
      In order to study the effect of self-healing behavior on recovery of mechanical properties of engineered cementitious composites (ECC) with high-volume fly ash, a new method for measuring the health/damage condition of concrete materials with resonance frequency is proposed.The resonance frequency test, uniaxial tensile test and optical microscope are employed to study the resonance frequency, stiffness, first cracking strength, tensile strain and crack pattern of ECC.The experimental results show that the resonance frequency can be recovered to more than 82% after 15 curing cycles.The second tensile properties of the pre-cracked ECC were obviously recovered, and the initial cracking stage reemerged.The degree of stiffness recovery can reach more than 58%, and the maximum tensile strain recovery degree is above 90%.Self-healing behavior can make the cracking strength of a part of self-healing crack more than that of the matrix.Therefore, it is feasible to produce ECC materials with high-volume fly ash, while maintaining higher material ductility and self-healing behavior simultaneously.
      作者: 邓涵文 [1] 钱吮智 [2]
      Author: Deng Hanwen [1] Qian Shunzhi [2]
      作者单位: 东南大学交通学院,南京,210096 东南大学交通学院,南京210096;南洋理工大学土木与环境工程学院,新加坡639798
      年,卷(期): 2017, 47(4)
      分类号: U414
      在线出版日期: 2017年8月15日
      基金项目: 国家自然科学基金资助项目,江苏省六大人才高峰计划资助项目