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The purpose of this study was to evaluate the structural performance of composite deck slabs containing macro-synthetic fibers. after a fire by proposing a deflection estimation method for non-fireproof structural decks. Therefore, this study evaluated the fire resistance performance and deflection of deck slabs mixed with macro-synthetic fibers. Afterward, the deflection estimation method considering the thermal characteristics of concrete and deck plates was proposed. A material test was first conducted to evaluate the mechanical properties of concrete mixed with macro-synthetic fibers. This test found that the compressive strength and elasticity modulus of concrete mixed with macro-synthetic fibers was greater than that of general concrete. A flexural tensile test confirmed that residual strength was maintained after the maximum strength was achieved. The fire resistance of the deck slab was adequate even when a fire-resistant coating was not applied. The internal temperature was lowest for the specimen with macro-synthetic fibers. Deflection was evaluated using previously published equations and standards. The deflection evaluation confirmed that the temperature distribution should be applied differently in the estimation method that uses the thermal load of the deck slab.
Dong-Hee Son; Hyo-Jun Ahn; Joo-Hong Chung; Baek-Il Bae; Chang-Sik Choi. Deflection Estimation Based on the Thermal Characteristics of Composite Deck Slabs Containing Macro-Synthetic Fibers. Materials 2021, 14, 4052 .
AMA StyleDong-Hee Son, Hyo-Jun Ahn, Joo-Hong Chung, Baek-Il Bae, Chang-Sik Choi. Deflection Estimation Based on the Thermal Characteristics of Composite Deck Slabs Containing Macro-Synthetic Fibers. Materials. 2021; 14 (14):4052.
Chicago/Turabian StyleDong-Hee Son; Hyo-Jun Ahn; Joo-Hong Chung; Baek-Il Bae; Chang-Sik Choi. 2021. "Deflection Estimation Based on the Thermal Characteristics of Composite Deck Slabs Containing Macro-Synthetic Fibers." Materials 14, no. 14: 4052.
Evaluation of the ultimate strength for the UHPFRC (ultra-high-performance fiber-reinforced concrete) flexural members was conducted. In this study, an experimental program about UHPFRC beams was conducted with the effect of fiber volume fraction, shear span to depth ratio, and compressive strength of matrix as the main variables. Among them, it was found that fiber volume fraction was the variable that had the greatest influence on the ultimate strength. The inclusion of 2% volume fraction steel fiber increases the shear and flexural strength of UHPFRC beams significantly. In particular, steel fiber inclusion changed the mode of failure of beams from diagonal shear failure into flexural failure. For the classification of failure patterns, the ultimate flexural strength and shear strength of UHPFRC members were evaluated using the current design code and UHPC guidelines. Flexural ultimate strength was affected by the size and shape of the stress block and consideration of the matrix’s tensile strength. For the accurate shear strength prediction of UHPFRC beams, the tensile strength of the high strength matrix and the effect of steel fiber should be considered.
Baek-Il Bae; Moon-Sung Lee; Chang-Sik Choi; Hyung-Suk Jung; Hyun-Ki Choi. Evaluation of the Ultimate Strength of the Ultra-High-Performance Fiber-Reinforced Concrete Beams. Applied Sciences 2021, 11, 2951 .
AMA StyleBaek-Il Bae, Moon-Sung Lee, Chang-Sik Choi, Hyung-Suk Jung, Hyun-Ki Choi. Evaluation of the Ultimate Strength of the Ultra-High-Performance Fiber-Reinforced Concrete Beams. Applied Sciences. 2021; 11 (7):2951.
Chicago/Turabian StyleBaek-Il Bae; Moon-Sung Lee; Chang-Sik Choi; Hyung-Suk Jung; Hyun-Ki Choi. 2021. "Evaluation of the Ultimate Strength of the Ultra-High-Performance Fiber-Reinforced Concrete Beams." Applied Sciences 11, no. 7: 2951.
In this research, flexural performance was evaluated using macro-synthetic fiber-reinforced concrete (MFRC) in structural deck plates. Material tests were performed to evaluate the mechanical properties of the MFRC, and the flexural strength evaluation was conducted in two experiments, positive and negative moment tests. In the material test results, compressive strength and modulus of elasticity of the MFRC were increased compared with normal concrete. Flexural tensile tests showed that, after achieving maximum strength, the deck plates had sufficient residual strength until fracture. Structural tests showed that flexural strength and cracking load of all specimens increased according to macro synthetic fiber dosage. According to the experimental results, we proposed a flexural strength model of a steel deck plate containing macro synthetic fiber. The model showed greater accuracy than the current standard compared with the experimental results. In addition, since it was confirmed that the MFRC steel decks had greater flexural stiffness until yielding, it will be necessary to quantitatively evaluate the effect of MFRC on the effective flexural stiffness of steel decking in future studies.
Dong-Hee Son; Baek-Il Bae; Moon-Sung Lee; Moon-Seok Lee; Chang-Sik Choi. Flexural Strength of Composite Deck Slab with Macro Synthetic Fiber Reinforced Concrete. Applied Sciences 2021, 11, 1662 .
AMA StyleDong-Hee Son, Baek-Il Bae, Moon-Sung Lee, Moon-Seok Lee, Chang-Sik Choi. Flexural Strength of Composite Deck Slab with Macro Synthetic Fiber Reinforced Concrete. Applied Sciences. 2021; 11 (4):1662.
Chicago/Turabian StyleDong-Hee Son; Baek-Il Bae; Moon-Sung Lee; Moon-Seok Lee; Chang-Sik Choi. 2021. "Flexural Strength of Composite Deck Slab with Macro Synthetic Fiber Reinforced Concrete." Applied Sciences 11, no. 4: 1662.
A study was conducted for the flexural retrofit of an old apartment house composed of a reinforced concrete (RC) shear wall structure. For the shear wall, a vertical retrofit was performed to both ends of the wall targeting the slender wall to improve the flexural performance. The retrofit materials were steel plate, epoxy, and non-shrink grout, and they were connected to the existing shear wall using post-installed chemical anchors. The concrete at the wall ends was broken and retrofitted as much as necessary to maintain the shear wall’s length. The points to be noted are the fracture of the welded part of the flexural retrofit and the chemical anchor’s pulling. After the real scale specimen was fabricated by simulating the existing shear wall, the retrofit effect was experimentally verified by breaking the wall ends, retrofitting the ends, and applying repeated cyclic lateral loads. A total of three specimens were fabricated and retrofitted using steel plates and steel tubes. Since this experiment evaluated the flexural performance, the experiment was performed with a cantilever setting. The flexural retrofit effect using steel was analyzed through the load–displacement relationship, stiffness degradation, and energy dissipation, and through this, the bond of the retrofit and the behavior of the wall were verified.
Su-Yong Kim; Uijin Cho; Joo-Hong Chung; Baek-Il Bae; Chang-Sik Choi. Seismic Performance of Existing RC Structural Walls Retrofitted in Flexure by Wall End Plate. Sustainability 2021, 13, 509 .
AMA StyleSu-Yong Kim, Uijin Cho, Joo-Hong Chung, Baek-Il Bae, Chang-Sik Choi. Seismic Performance of Existing RC Structural Walls Retrofitted in Flexure by Wall End Plate. Sustainability. 2021; 13 (2):509.
Chicago/Turabian StyleSu-Yong Kim; Uijin Cho; Joo-Hong Chung; Baek-Il Bae; Chang-Sik Choi. 2021. "Seismic Performance of Existing RC Structural Walls Retrofitted in Flexure by Wall End Plate." Sustainability 13, no. 2: 509.
The purpose of this study was to evaluate the structural performance of steel fiber reinforced concrete (SFRC) coupling beams. Reversed cyclic loading tests were performed with full-scale specimens. The main variable for the tests was the volume fraction ratio of the steel fibers. The results showed that the maximum strength was increased by about 11% with 1% of steel fibers incorporated, and about 24% when the ratio of mixed fibers was doubled to 2%. Because numerous microcracks occurred, decreased crack width due to the bridge effect was observed with the steel fiber reinforcement. Increased diagonal tension crack angles and energy dissipation also appeared as the volume fraction of steel fibers increased. The contribution of shear to the total deformation was decreased while the contribution of rocking was increased as steel fibers were added. Considering the results of these experiments, it can be concluded that steel fiber reinforcement affects the deformation of coupling beams in various ways, and should be considered when estimating the effective stiffness of such beams when SFRC is introduced.
Joo-Hong Chung; Dong-Hee Son; Su-Yong Kim; Baek-Il Bae; Chang-Sik Choi. Hysteretic Behavior of Reinforced Concrete Coupling Beams According to Volume Fraction of Steel Fiber. Sustainability 2020, 13, 182 .
AMA StyleJoo-Hong Chung, Dong-Hee Son, Su-Yong Kim, Baek-Il Bae, Chang-Sik Choi. Hysteretic Behavior of Reinforced Concrete Coupling Beams According to Volume Fraction of Steel Fiber. Sustainability. 2020; 13 (1):182.
Chicago/Turabian StyleJoo-Hong Chung; Dong-Hee Son; Su-Yong Kim; Baek-Il Bae; Chang-Sik Choi. 2020. "Hysteretic Behavior of Reinforced Concrete Coupling Beams According to Volume Fraction of Steel Fiber." Sustainability 13, no. 1: 182.
This study proposed a phased reverse engineering framework to construct cultural heritage archives using laser scanning and a building information model (BIM). This framework includes acquisition of point cloud data through laser scanning. Unlike previous studies, in this study, a standard for authoring BIM data was established through comparative analysis of existing archives and point cloud data, and a method of building valuable BIM data as an information model was proposed. From a short-term perspective, additional archives such as member lists and drawings can be extracted from BIM data built as an information model. In addition, from a long-term perspective, a scenario for using the cultural heritage archive consisting of historical records, point cloud data, and BIM data was presented. These scenarios were verified through a case study. In particular, through the BIM data building and management method, relatively very light BIM data (499 MB) could be built based on point cloud data (more than 917 MB), which is a large amount of data.
Namhyuk Ham; Baek-Il Bae; Ok-Kyung Yuh. Phased Reverse Engineering Framework for Sustainable Cultural Heritage Archives Using Laser Scanning and BIM: The Case of the Hwanggungwoo (Seoul, Korea). Sustainability 2020, 12, 8108 .
AMA StyleNamhyuk Ham, Baek-Il Bae, Ok-Kyung Yuh. Phased Reverse Engineering Framework for Sustainable Cultural Heritage Archives Using Laser Scanning and BIM: The Case of the Hwanggungwoo (Seoul, Korea). Sustainability. 2020; 12 (19):8108.
Chicago/Turabian StyleNamhyuk Ham; Baek-Il Bae; Ok-Kyung Yuh. 2020. "Phased Reverse Engineering Framework for Sustainable Cultural Heritage Archives Using Laser Scanning and BIM: The Case of the Hwanggungwoo (Seoul, Korea)." Sustainability 12, no. 19: 8108.