• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.04a
• /
• pp.345-352
• /
• 2001

Recent destructive seismic events demonstrated the importance of mitigating human casualties and serious property damages in design and construction of structures. The Korean Bridge Design Specifications (1992) adopted seismic design requirements based on the AASHTO specification, and minor modification was made in 2000. The longitudinal steel connection of reinforced concrete bridge column is sometimes practically unavoidable. The longitudinal reinforcement details affect seisimc performance such as flexural failure and shear failure. This research aims to develop longitudinal steel connection details with confinement steel by experimental study for seismic performance of reinforced concrete bridge columns. Quasi-static test under three different axial load levels was conducted for 12 spiral column specimens. All the column specimens had the same aspect ratio of 3.5. The column specimens were transversely reinforced with spiral and with five different longitudinal steel connection. The final objective of this study is to suggest appropriate longitudinal reinforcement connection details for the limited ductility design concept and improve construction quality.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.309-312
• /
• 2006

In this study, the repair method using PVA fiber reinforced mortar evaluated on durability performance. Test items are compressive strength, flexural strength, carbonation, freezing-thawing. As for the test results, it was found that durability performance of the repair method using PVA fiber mortar showed more better than the existing repair method. Therefore, appling on the repair method using PVA fiber mortar, the repaired concrete structures can be increased to service life.

• Structural Engineering and Mechanics
• /
• v.50 no.6
• /
• pp.741-754
• /
• 2014

The conventional PHC pile-footing connection is the weak part because the surface area and stiffness are sharply changed. The Composite PHC pile reinforced with the transverse shear reinforcing bars and infilled-concrete, hereafter ICP pile, has been developed for improving the flexural and shear performance. This paper investigates the cyclic behavior and performance of the ICP pile-footing connection. To investigate the behavior of the connection, one PHC and two ICP specimens were manufactured and then a series of cyclic loading tests were performed. From the test results, it was found that the ICP pile-footing connection exhibited higher cyclic behavior and connection performance compared to the conventional PHC pile-footing connection in terms of ductility ratio, stiffness degradation and energy dissipation capacity.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.943-948
• /
• 2003

The experimental study for oblong section was carried out by the column test in weak axis. The column specimens had 3 types of transverse steel configurations, such as interlocking spirals, interlocking circular hoop ties and rectangular ties. The oblong columns with interlocking spirals and with interlocking circular hoop ties showed better seismic performance than the rectangular columns with rectangular hoops and cross-ties. The objectives of this study were to provide experimental data on the behavior of interlocking spiral columns under cyclic loading, to compare the performance of columns with interlocking spirals to columns with various transverse steel configurations, to study the flexural detailing of interlocking spirals, interlocking circular hoops, and other transverse steel configurations as the transverse reinforcement, and to make recommendations for the design of bridge columns incorporating interlocking spirals, circular hoops as the transverse reinforcement.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.279-282
• /
• 2012

This study attempted to the effect on the physical performance of silane coupling agent on solventless epoxy-based concrete surface finishing material for parking floor. Tests were carried out in accordance with KS F 4041 and KS F 4937. The results of compressive strength, flexural compressive are 95.6N/㎟, 25.4N/㎟ and after wheel moving load testing, average abrasive depth is 0.96mm, these results satisfied the quality standard of KS F 4041, KS F 4937. As conclusion, this study confirmed that the silane coupling agent greatly effected on the physical performance of solventless epoxy resin.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.05a
• /
• pp.275-276
• /
• 2018

Ultra high performance concrete(UHPC) represents high early age autogenous shrinkage strain due to its low water-to-binder ratio(W/B) and high fineness admixture usage. It has been reported that fiber can control restrained tensile stress and crack. The purpose of the present study is, therefore, to investigate the autogenous shrinkage as well as mechanical properties including compressive strength, flexural strength and modulus of elasticity on the UHPC with fiber type and pre-mix of binder.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.05a
• /
• pp.17-18
• /
• 2018

With the technological advancement of the construction industry, construction materials with future direction appeared. In Korea, LEFC(Light Emotion Friendly Concrete) has been developed and studied, which has improved labor productivity and economic efficiency over semi-transparent concrete by introducing transparent plastic rods into concrete matrix. However, there is a problem in that the bending performance is lowered according to the insertion of the rod and the bending performance is different according to the light transmission direction. In this study, the incorporation of PVA fibers in the direction of light transmission was increased and the change of flexural performance according to the interval of light transmission was examined.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.05a
• /
• pp.63-64
• /
• 2019

Due to the rapid deterioration of the domestic atmosphere, people are suffering from inconveniences such as wearing fine dust masks all the time during outdoor activities. In this study, light transmitting concrete, LEFC(Light Emotion Friendly Concrete), using TiO2 photocatalyst was produced. Since the characteristics of LEFC where acrylic rods are inserted require self-consolidating performance, the purpose was to utilize UHPC(Ultra High Performance Concrete) materials to obtain high-flowability. Further, the compressive strength and flexural strength were evaluated to prevent the reduction of epidemiological performance by utilizing UHPC materials. As such, a basic study was carried out to develop LEFC materials using photocatalyst that can purify the air and stimulate human sensibility.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.813-816
• /
• 2004

This study was performed to investigate bonding performance of epoxy resins for repairing of cracks in concrete, as a part of project to establish quality control standard for epoxy resins. In the slant shear strength test for hard and soft type epoxy, hard type was higher about 3 times than soft one. From the results, it is thought that hard type is suitable for load carrying. Injection of epoxy resin in the notch made flexural strength increase about $47\%$ over the specimen that epoxy resin is not injected. There were no differences in bonding performances with viscosity. Application of epoxy resin on the wet concrete surface made slant shear strength decrease about $46\%$, but similar performance to the case of application on the dry surface appeared by using epoxy resin for wet condition.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.573-576
• /
• 2004

High performance SFRC composed of mira-sized ultra fine particles is characterized by high strength, high ductility and excellent durability. therefore many researches about materials based on new composition like this are performed recently. many researchers have reported that adding steel fiber to concrete improved its tensile and flexural strength significantly. the main objective of this research is to examine the effect of adding steel fiber on the tensile strength of high performance SFRC. variables considered in this study are w/c ratio and fiber volume fraction.