• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.61-64
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• 2004

This study presents results from an experimental work for two normal prestressed concrete beams and three dual prestressed concrete beams. The dual prestressed concrete beams made with normal concrete in compression zone and high performance steel fiber reinforced concrete in partial depth of tension zone. Through cyclic loading test under low frequency, structural behavior and resistance to dynamic loading for dual prestressed concrete beams are investigated. Considerable increase of crack and yield load capacity of Dual prestressed concrete beam is shown compared with normal prestressed concrete beam. In addition, re-loading and un-loading rigidity of dual prestressed concrete beam under cyclic loading are increased comparing with normal prestressed concrete beam.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.341-344
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• 2004

In the present research, slump, modulus of rupture (MOR) and flexural toughness $(I_{30})$ of high performance hybrid fiber reinforced concrete (HPHFRC) mixed with micro-fiber (carbon fiber) and macro-fiber (steel fiber) and replaced with silica fume were assessed with the analysis of variance (ANOVA). Steel fiber was a considerable significant factor in aspect of the response values of MOR and boo Based on the significance of factors related to response values from ANOVA, following assessments were available; Slump decrease: carbon fiber >> steel fiber > silica fume; MOR: steel fiber > silica fume > carbon fiber; $I_{30}$: steel fiber > carbon fiber > silica fume. Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $5.0\%$, and Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $2.5\%$ were obtained as the most optimum mixture.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.122-126
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• 2012

Steel lining board usually is used as a floor on the temporary steel bridges. It also is installed in the subway construction site. However, in particular in subway construction, renovations and site of old bridges, these steel lining board structures have a problem such as noise, accidents and slip hazards. So steel composite lining board is being developed to solve this problem. Steel composite lining board consists of compressive concrete showing excellent performance in slip, durability, resistance and noise, lower tensile and shear steel showing high safety, effective and superior workability in many respects. Steel composite lining board structure gradually is used in many construction sites, because it has a high quality such as durability, little noise and slip. In this study, flexural tests of steel composite lining board in accordance with welding patterns were conducted to compare the performance of the structure.

• Steel and Composite Structures
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• v.29 no.4
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• pp.509-526
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• 2018

The direct strength method adopted by the AISI Standard and AS/NZS 4600 is an advanced design method meant to substitute the effective width method for the design of cold-formed steel structural members accounting for local instability of thin plate elements. It was proven that the design strength formula for the direct strength method could predict the ultimate strength of medium strength steel welded section compressive and flexural members with local buckling reasonably. This paper focuses on the modification of the direct strength formula for the application to high strength and high performance steel welded section columns which have the nominal yield stress higher than 460 MPa and undergo local buckling, overall buckling or their interaction. The resistance of high strength steel welded H and Box section columns calculated by the proposed direct strength formulae were validated by comparison with various compression test results, FE results, and predictions by existing specifications.

• Advances in concrete construction
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• v.5 no.1
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• pp.1-15
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• 2017

This research project aimed at evaluating experimentally the effect of natural perlite powder as an alternative supplementary cementing material (SCM) on the performance of fiber reinforced self-consolidating repair mortars (FR-SCRMs). For this purpose, four FR-SCRMs mixes incorporating 0%, 10%, 20%, and 30% of natural perlite powder as cement replacements were prepared. The evaluation was based on fresh (slump flow, flow time, and unit weight), hardened (air-dry unit weight, compressive and flexural strengths, dynamic modulus of elasticity), and durability (water absorption test) performances. The results reveal that structural repair mortars confronting the performance requirements of class R4 materials (European Standard EN 1504-3) could be designed using 10%, 20%, and 30% of perlite powder as cement substitutions. Bonding results between repair mortars containing perlite powder and old concrete substrate investigated by the slant shear test showed good interlocking justifying the effectiveness of these produced mortars.

• Journal of Korean Association for Spatial Structures
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• v.19 no.1
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• pp.65-73
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• 2019

This paper assesses the structural performance (force-slip response, slip modulus, and failure modes) of a CLT-concrete composite by conducting fifteen push-out test specimens. In addition, non-linear 3D finite element analysis was also developed to simulate the load-slip behavior of the CLT-concrete specimens under shear load. All 15 test specimens simulating the effect of concrete thickness, connection angle and penetration depth with four different shear connector types were built and tested to evaluate the flexural performance. Experimental results show that the maximum shear capacity for the composite action is obtained when the fixing angle is $90^{\circ}$ and the penetration depth of 95mm for SC normal screw was used to achieve ductile failure compared to other shear connectors.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.128-129
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• 2020

In this study, flexural strength and tile adhesion strength were evaluated by using a mortar, dry mortar and an epoxy resin reinforced mortar to examine the adhesion performance by reinforcing the epoxy resin adhesive. As a result, it was clearly confirmed that the effect of improving the adhesion strength by reinforcing the epoxy resin adhesive regardless of the type of tile, and in particular, when applying the epoxy resin adhesive to the porcelain and polishing tiles, it is judged that sufficient adhesion performance can be secured.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.299-300
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• 2023

In this study, the performance evaluation and structural safety of rainwater permeation detention block were analyzed. As a result, the compressive strength (19.3 MPa), flexural strength (5.2 MPa), and permeability coefficient (2.0 mm/s) of the eco-friendly prefabricated rainwater permeable detention block satisfied the KS F 4419 and SPS-KCIC0001-0703 and it was confirmed sufficient safety even under maximum load.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.83-84
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• 2023

In this study, in order to utilize waste fishing net as a building materail, the possibility of replacing the fiber used in polymer repair mortar with waste fishing net fiber was confirmed. As for basic characteristics, flow, compressive strength, and flexural strength tests were performed to compare and analyze fiber performance, and the test results showed performance equal to or better than existing fibers.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.3
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• pp.105-115
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• 2007

Repair and Reinforcement are subjected change to increasing of remodelling. The usage of carbon fiber sheets is increasing for the strengthening of reinforce concrete structures. Therefore experimental and analytical studies are carry out to investigate the flexural behaviors of the strengthened RC structures by the external bonding of the new reinforcement method. Also the aim of this study is to investigate reinforcing method of FRP panel deal with fatigue loading through experiments.