Multi-Step Prestressing with Hybrid SMA Wires

Applied Sciences

Jong-Han Lee¹  Tae-Ryeon Woo²  Chi-Young Jung³ 

[1] Department of Civil Engineering, Inha University, Incheon 22212, Korea;Department of Civil Engineering, Pusan National University, Busan 46231, Korea;Seismic Research and Test Center, Pusan National University, Yangsan 50612, Korea;

关键词: multi-stepwise prestressing;    shape memory alloy;    nitinol;    hybrid SMA wire;   

DOI  :  10.3390/app10082842

来源: DOAJ

【 摘 要 】

Prestressing force is induced in reinforced concrete (RC) structures to improve their load-carrying capacity. Generally, the prestressing strand of an RC structure is tensioned using a hydraulic jack, which decreases its workability. In this study, we evaluate the application of prestressing force by using a shape memory alloy (SMA), as has been actively studied in civil engineering. Experiments were conducted to measure the multi-stepwise prestressing force introduced in a hybrid SMA wire composed of two different types of SMA wires. The experimental parameters were determined based on the combinations of the SMA wires and the heating temperatures. The results of the experiments show that the prestressing force was induced in a sequence. The magnitude of the prestressing force generated by the hybrid SMA wire was equal to the sum of the prestressing forces generated by the NiTi50 and NiTi90 SMA wires. In conclusion, this study verified the applicability of the proposed concept of multi-stepwise prestressing by using hybrid SMA wires. Further research is required to measure the effect of prestressing by locally heating the center of a girder with the aim of expanding the applicability of this concept.

【 授权许可】

Unknown