• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.135-145
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• 1992

With the increasing tendency to construct high rise reinforced concrete building~i, it is required to use high strength materIals, smaller member sections, and larger reinforcing bars, I t is generally recognized that under severe seismic loads beam column jomts may become more critical structural components than other structural elements. In a ductile momentresistmg reinforced concrete frame, the connection of bearncolumn must be capable of resistll1g the large lateral forces caused by seismic actions, The purpose of this experimental study is to evaluate and ll1vestigate the earthquake resistant perform ance of beam-colurrm subassemblies constructed with high-strength concrete cast by the concrete of com¬pressive strength of 700kg / cm2 subjected to reversed cyclic loadings. New approaches for moving the plastic hinging zone away from the column face and preventing the di¬agonal crack in the joint region are adopted to advance the earthquake-resistant performance of beam-column subassemblies using high-strengh concrete under severe earthquake-type loading. Exper¬imental results indicate that the modified new details which are introduced by intermediate reinforcement in the beam over a specific beam length adjacent to the joint are able to attain the stable hysteretic behavior and the enhancement of earthquake-resistant performance. Keywords: high strength concrete: beam-column Joints; seirnic loads(reversed cyclic loading) : earth¬quake-resistant performance; plastic hinge zone: diagonal crack: intermediate reinforce¬ment ; closed strirrup: hysteretic behavior: enhancement .

• Land and Housing Review
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• v.12 no.4
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• pp.119-125
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• 2021

The study presents the ductility reinforcement effect of the RC bending member using the CFRP Grid as an experimental result. Experimental variables include a non-reinforced RC bending member (ORI), a bottom reinforced RC bending member (REB), and an RC bending member reinforced at the bottom and side (REBS). The experiment was carried out with four points bending test. As a result of the experiment, it was confirmed that the maximum bending strength increased by 17-20% through reinforcement. In addition, the ductility index calculation results confirmed that the ductility index of REB and REBS increased by 2 and 3 times, respectively, compared to the ORI.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.969-974
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• 2008

This study was carried out to investigate the service life of reinforced concrete structures for durability design. The service life has three aspects physical service life, functional service life, and social service life, and that a structures are normally demolished to end its service life when either the functional or social service life is over before the physical service life comes to end an end. In the future, it is very important that durability design shall be performed establishing design service life and the unallowable state of deterioration in the course of design service life.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.535-542
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• 2005

Two series of experiments on the performance of beam-column joints in High-Strength Reinforced concrete frames were carried out. Main experimental parameters were : concrete strength, column axial load and amount of joint hoop reinforcement. Test result showed that the ultimate shear strength of exterior joints increased of column axial compressive force and the amount of the joint hoop reinforcements. Through the regression analysis on the 24data, the following equation is obtained $jv_u=(2.935{\times}10-3\;{\rho}jw{\cdot}fy\;+\;0.365){\sqrt{f_{ck}}}$

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.479-480
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• 2010

The efforts to achieve high-performance, durable reinforced concrete structures have increased the demands for improving the performance of both the concrete and the reinforcing materials. Researches for the hybrid reinforcing technique, which is maximizing the performance of high-strength concrete structures by applying the combination of high performance reinforcing materials, were performed in this study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.38-43
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• 1989

An improved model for predicting the reinforced concrete element behavior under dynamic strain rates was developed using the layer modeling technique. The developed strain rate sensitive model for axial/flexural analysis of reinforced concrete elements was uses to predict the test results, performed at different loading rates, and the predictions were reasonable. The developed analysis technique was used to study the loading rate sensitivity of reinforced concrete beams and columns with different geometry and material properties. Two design formulas for computing the loading rate dependent axial and flexural strengths of reinforced concrete sections were also suggested.

• Magazine of the Korea Concrete Institute
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• v.2 no.2
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• pp.73-80
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• 1990

The current analytical techniques for R/C elements under severe dynamic repeated loads, like earth¬quake or impact, have two major problems; one is that the effects of strain rate are not considered and the other one is the current analytical model was developed based on flexural behavior only. This study develops computer software that can idealize the flexural and shear behavior of R/C elements using several parameters and also can consider the effects of strain rate. The analytical results using the developed technique were compared with serveral experimental results and they were generally satisfied.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.179-183
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• 2008

Methods of damage detection are used non-destructive test in concrete structures. These are using various sensors, but the most of damage detections are used a visual angle of human. Problems of crack damage detection are occurred to directions and boundary conditions of steel bars using accelerometer in concrete element. In this study, fundamental studies for estimation using 3 axial type of accelerometer and electric resistance property of thermocouple sensors are discussed estimation to effect of arranged steel bars and damage from low strength when they are oscillated elastic wave in concrete specimen.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.57-58
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• 2009

This paper reports experimental data on the structural performance of reinforced concrete beams with recycled aggregates. Reinforced concrete beams with recycled coarse aggregate and recycled sands were tested to evaluate their failure modes, flexural behavior and compared with a standard.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.173-176
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• 2008

Use of concrete has undoubtedly become widespread in construction. Sensors are used to add functional characteristics to concrete. Self-diagnosing, smart concrete is also being developed. Development of these functional materials and structures will play an important role in protecting buildings and structures against external factors brought about by unusual weather among others. In this study, the innovative measurement system is presented where material damages and internal stress can simply be detected against the compressive and bending force of the structure using light-emitting diode and the resistance property of electric fuse.