Strengthening Concrete Structures with Smart Materials

钢筋混凝土(RC)结构的劣化是一个永无止境的问题，激励着世界各地的土木工程师寻求创新的耐久加固技术和高性能的先进材料。近年来，一类新的智能材料形状记忆合金(SMA)以其优异的性能吸引了来自不同领域的研究人员的注意。SMA是一种独特的合金，能够承受较大的变形，并通过消除应力恢复到原来的形状。形状记忆合金除了具有超弹性、耐腐蚀和耐疲劳性能外，还具有形状记忆效应(SME)现象，而形状记忆效应是通过其独特的热机械性能遗传而来的。SME代表SMA在加热时变形超过弹性极限后恢复其原始形状的能力。具有SME性质的SMAS可以作为体外预应力钢筋，对钢筋混凝土构件进行主动加固。

Deterioration of Reinforced Concrete (RC) structures is a never-ending problem that incites civil engineers around the world to seek innovative durable strengthening techniques and high performance advanced materials. Recently, a new class of smart materials called Shape Memory Alloys (SMA) has been attracting the attention of researchers from different fields due to their superior properties. The SMA is a unique class of alloy with the ability to undergo large deformations and return to its original shape through stress removal. Besides their super-elasticity, corrosion and fatigue resistivity, SMAs are mainly characterized by the Shape Memory Effect (SME) phenomenon that is inherited through their unique thermo-mechanical properties. The SME represents the ability of the SMAs to recover their original shape after being deformed beyond the elastic limits upon heating. SMAs with the SME property can be used as external prestressed reinforcement by providing active strengthening to RC members.