不同环境对超高韧性水泥基复合材料裂缝自愈合的影响

Effect of different environments on crack self-healing engineered cementitious composite

通过对超高韧性水泥基复合材料(ECC)预加不同程度拉伸应变产生裂缝,测定自愈合过程中的共振频率(RF),探究了干湿循环(C1)、湿热循环(C2)、水(C3)及空气(C4)等不同环境对ECC裂缝自愈合的影响,为其应用于实际工程中提供了依据。结果表明:水对裂缝的自愈合起到了至关重要的作用;不同环境中RF的增长主要发生在3~7d内;10个自愈合循环后,由裂缝自愈合导致的RF的实际增长也高达近70%;不同环境中RF增长的顺序为:C3>C1>C2>C4;不同配比相比较,HFA-ECC的RF恢复值高于M45-ECC。ECC裂缝能发生明显的自愈合,具有较好的应用前景。

By the tensile test of ECC at different pre-loading , the paper measured the resonant frequency ( RF ) in the process of self recovery , and studied the effect of different conditioning cycles including wet/dry (C1), water/hot air (C2), water (C3) and air (C4) on crack self-healing of ECC materials, thus provided the basis for the application of practical engineering .The results show that water plays a vi-tal role for self-healing.The increase of RF under different conditioning cycles mainly occurrs within 3 to 7 days.After 10 cycles,the actual RF recovery due to self-healing is nearly 70%.The order of RF recovery under different conditioning cycles is C 3>C1>C2>C4.Compared to different ratio of ECC , HFA-ECC has higher RF recovery than that of M45-ECC.The crack of ECC can produce apparent self-healing.ECC has good application prospect .