The utilization of composite columns is increasing due to the construction of high-rise buildings and large buildings. The commercially available concrete chimney steel column (ACT I) is a stable and economical structure, but there is a limit in the section size to be applied to a composite column subjected to a high load. We have developed a composite mega column with an integral structure by adding a plate to the central part of the ACT I column and installing a binding frame at a certain interval inside the central plate. In this study, to evaluate the compressive performance of the composite mega column, four test specimens were constructed with binding frame reinforcement, reinforcement spacing, and reinforced cross - sectional area. The structural performance of the composite section is compared with that of KBC2016 to evaluate the behavior of the specimen.

Recently, as the number of earthquakes has increased, the building structure standard has been revised in 2016. In order to minimize earthquake damage, steel frame is used as the most economical and efficient lateral resistance system. Also, when the steel braces are subject to Compressive load, which causes unstable behavior of the structure. In order to verify the compressive behavior of the reinforced Braces, structural performance tests were conducted with variables of slenderness ratio and the amount of reinforcement. This study investigates the structural performance of existing double - angle steel braces by reinforcing them with non- welded/assembled light-weight steel frames and proposes a suitable reinforced section.

These days, the Composite Slabs with Deep Deck plate was commonly used in domestic construction site, and, the application of the Slim Floor system was increased from the Enlargement and High-rise Building. But, Slim Floor system using the Deep Deck was shown safety problem caused by the deflection and local buckling in construction phase when used to more than 6m. Therefore, for solving the problem, the installation of the shores is essential. This study is realize the long span slab without shores from control the deflection through applied the pre-tensioning elements in CAP deck. In addition, by applying the pre-tensioning member as the tensile member of the CAP Deck slab, the pre-tensioning member for the shores tries to be used as the structural member. Accordingly, to determine the flexural performance of the CAP Deck slab through the pre-tensioning force in tensile member, and, the composite effect of the CAP Deck slab by the experiments.

In this study the structural performance of new composite column to composite beam connection was evaluated by cyclic tests. It is designed to be applied to various types of through type system to the bottom plate to view synthesis composite beam. A composite column is composed of a RC type column reinforced by steel angles which the end bends in each edge corners of column. also, A composite beam is composed of trussed type’s web, a bottom steel plate and reinforced by steel angles which the end bends in each edge corners of beam. 4 cyclic tests of the clarified structural performance of the connections are performed. All specimens that is apply reinforced concrete beam-column joints based on KBC2009 criteria was performed by cyclic test of column to beam. All specimens were exposed to be satisfied with the required ultimate strength.

Axial force of the bolt is very important for structural stability. To obtain stability of the structure, axial force of the bolt should satisfy the specification and be maintained over the time. Hence, It is important to the axial force of the bolt is measured and it manages. However, measuring of the axial force using sensors is very expensive. Torque method using frequently in the field is difficult to confirm accurately by the torque coefficient change. In this study, measuring of axial force using elastic force of the spring washer was studied. First, the relational formula is drawn about the pressure in which the spring washer model changes to the annular of the plane state. According to the axial force of the bolt, the necessity height of the spring washer is presented and the finite-element analysis model is recommended. The analysis model research, generally, the axial force of high strength bolt is confirmed. It expands to confirmation of the large caliber bolt.