SMA混凝土梁的裂缝监测及自修复

Self-monitoring and Repairing Based on Crack of Concrete Beam Embedded with SMA

试验研究了混凝土梁加载过程中Ni-Ti形状记忆合金(shape memory alloy,简称SMA)丝电阻变化率与混凝土梁裂缝宽度的关系和SMA丝通电激励过程中混凝土梁裂缝恢复的变化规律.结果表明:SMA丝电阻变化率随混凝土梁裂缝宽度的增加呈现出规律性的变化,尤其是当混凝土裂缝在0.3 mm范围内变化时其电阻变化率对梁裂缝变化更为敏感;SMA丝通电激励后的恢复特性能使SMA混凝土梁的裂缝很好愈合.利用SMA丝电阻变化率对裂缝变化的敏感性和其相位恢复特性可实现对混凝土梁裂缝的自监测和自修复.

An experimental research on concrete beams embedded with pre-stretch Ni-Ti shape memory alloy（SMA） wires was presented during the martensite phase at room temperature, the relationship between resistance change rate of SMA and crack width of concrete beam was tested and the self-repairing of crack was realized while the SMA was excited, the influence of different pre-stretch and clamp had been taken into account in the experiment. The result shows that the resistance change rate of SMA is sensitive to the change of crack width and the recover property of phase variation can realize the crack self-repairing. The sensitive property of resistance change rate and recover property can be used to concrete beam monitoring and self-repairing temporarily.