|
Title |
Flexural Behavior of Concrete Beams Reinforced with Fe based Shape Memory Alloy Bar
|
|
Authors |
홍기남(Ki-Nam Hong) ; 연영모(Yeong-Mo Yeon) ; 지상원(Sang-Won Ji) |
|
DOI |
https://doi.org/10.11112/jksmi.2020.24.6.67 |
|
Keywords |
철계-형상기억합금; 회복응력; 프리스트레스; 초기균열 Fe based shape memory alloy; Recovery stress; Pre-stress; Initial crack |
|
Abstract |
This paper reports an experimental study to evaluate the flexural behavior of concrete beams reinforced using Fe based shape memory alloy (Fe-SMA) bars. For the experiment, a concrete beam of 200mm×300mm×2,200mm was produced, and a 4% pre-strained Fe-SMA bar was used as a tensile reinforcement. As experimental variables, type of tensile reinforcement (SD400, Fe-SMA), reinforcement ratio (0.2, 0.39, 0.59, 0.78), activation of Fe-SMA (activation, non-activation), and joint method of Fe-SMA bar (Continuous, welding, coupler) were considered. The electric resistance heating method was used to activate the Fe-SMA bar, and a current of 5A/mm2 was supplied until the specimen reached 160°C. After the upward displacement of the specimen due to the camber effect was stabilized, a three-point flexural loading experiment was performed using an actuator of 2,000 kN capacity. As a result of the experiment, it was found that the upward displacement occurred due to the camber effect as the Fe-SMA bar was activated. The specimen that activated the Fe-SMA bar had an initial crack at a higher load than the specimen that did not activate it. However, as with general prestressed concrete, the effect of the prestress by Fe-SMA activation on the ultimate state of the beam was insignificant.
|