A feasibility study on improving the crack resistance of thin-walled UHPC members by reinforcement with Fe-SMA wires.

To investigate the potential for further enhancing the cracking resistance of thin-walled UHPC by prestressing, the uniaxial tensile and three-point bending experiments for UHPC specimens reinforced with iron-based shape memory alloy (Fe-SMA) wires were conducted. The specimens were placed in an oven and heated to 150 °C, 200 °C, and 250 °C, which was intended to activate the Fe-SMA wires to produce self-prestress. The characteristics of different reinforced methods and heating temperatures were systematically compared. The cracking load and the crack development were recorded using Digital Image Correlation (DIC) techniques. The result shows that at the temperature of 150 ºC, compared to the dog-bone shaped specimens without reinforcement and the specimens with steel wires, the mean cracking load of specimens with Fe-SMA wires was enhanced by 13.4% and 9.8%, respectively. The study preliminary verified that this method can activate Fe-SMA inside UHPC. [ABSTRACT FROM AUTHOR]