Experimental Study on Flexural Behavior of Seawater Sea-Sand Concrete Beams Reinforced with Superelastic Shape Memory Alloy Bars

In order to research the flexural behavior of shape memory alloy (SMA)-reinforced seawater sea-sand concrete (SWSSC) beams and improve their self-healing ability, three SMA SWSSC beams and one anti-corrosive steel bar SWSSC beam were designed. The influence of the reinforcement ratio, strength grade of SWSSC and type of reinforcement on the flexural performance of the beam were considered. The failure process, maximum crack width, mid-span deflection, displacement ductility and stiffness degradation of beams were studied by cyclic loading tests. The test results showed that the number of cracks in SMA-reinforced beams were significantly smaller than that in anti-corrosive-reinforced beams, and the crack width and mid-span deflection recovery effect were better after unloading. However, the effect of increasing the SMA reinforcement ratio on crack recovery was not obvious. The increase in SMA reinforcement ratio and the strength grade of SWSSC can significantly improve the bearing capacity of the beam and the stiffness, but the stiffness degradation rate decreased. Moreover, the ductility of concrete beams with SMA bars was significantly increased.