形状记忆合金智能混凝土连续梁的变形特性的研究

Deformation property of smart concrete continuous beams reinforced with shape memory alloy rebars

利用形状记忆合金(Shape memor yalloy,简称SMA)的形状记忆效应,配制智能混凝土连续梁。运用试验方法研究SMA智能混凝土梁自修复特性的规律及其影响因素,并分析SMA对连续梁的过大变形及裂缝的修复机理。研究结果表明:预先配置的SMA能够显著提高混凝土梁的刚度;通电激励加热的方法,SMA钢筋能够提供显著的恢复力,有效减小梁的挠度和裂缝宽度;增加合金的总截面面积,即提高SMA丝的配筋率,可提高合金对混凝土梁的驱动效果;在混凝土梁中配置受拉钢筋,虽然可以提高梁的承载能力,但钢筋的塑性变形对SMA梁的变形恢复又起到阻碍作用,会影响梁的修复效果。

A new method to manufacture smart reinforced concrete continuous beams by using the shape memory effect of the shape memory alloy was developed.An experimental method was applied to research the self-repairing property and the influenced factors of the SMA smart beams,and to analyze the self-repairing mechanism of the large deformation and wide width of cracks for the beams.The research results showed that the stiffness of the beam can be significantly increased by pre-placing the SMA rebars,that the SMA rebar can provide enough resilience force to effectively reduce the deformation and the width of the beam by Joule heating method,that the actuating effect of the SMA to the beam can be increased by adding the total area of the cross section of the SMA rebars or the reinforcement ration of the SMA,and that the plastic deformation of the normal reinforcement can resist the self-repairing effect of the SMA rebars if placing the normal reinforcement in the beam although they can increase the bearing capacity of the beam.