| 요약2 |
As the construction of high-rise residential buildings increases, the reduction of story height and the improvement of construction efficiency are demanded. Authors develop iTECH(Innovative, Technical, Economical, & Convenient Hybrid) beam through which the reduced height (as shallow as RC wide beam), the improvement of serviceability, and the excellent fire proof can be achieved. iTECH beam is a sort of composite beam that consists of asymmetric steel with web opening and concrete. However, the shear connectors such as stud bolts are not used, instead the longitudinal shear strength is obtained through bond strength of interface and bearing strength of the opened web area. In this research, the flexural behavior of iTECH beam, such as strength, ductility, serviceability and composite action, was assessed by T section beam test. For the comparison, Slim Floor beam is tested and bare steel iTECH beam is also tested to evaluate the resistance for construction loads.
To get the ultimate capacity of the structural element, iTECH is designed as full composite beam during the service load state and partial composite beam after yield. The test results show that iTECH behaved properly as expected. Despite the partial composite action, the strength exceeded the design value by 17%. Because the longitudinal shear force after the yield was kept constant over the design strength, iTECH failed from concrete crushing without bond or local failure. Therefore, every structural element could be efficiently utilized.
Slim Floor's behavior was very similar to that of iTECH. The slippage, however, occurred before the yield, because the longitudinal shear strength was slightly less than the required strength for fully composite action until yield. The bare steel iTECH failed due to the buckling of upper flange. The effective length coefficient was found to be 0.75. From the results of this research, iTECH beam is expected to be properly used as the floor system of high-rise residential buildings. |