• 콘크리트학회논문집
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• 제11권5호
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• pp.3-10
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• 1999

Earthquake resistant R/C frame structures are generally designed to prevent the columns from plastic hinging. R/C columns under higher axial load or strong earthquake showed a brittle behavior due to the deterioration of strength and stiffness degradation. An experimental study was conducted to examine the behavior and to find the relationship between amounts of lateral reinforcements and compressive strength of ten R/C column specimens subjected to reversed cyclic lateral load and higher axial load. Test results are follows : An increase in the amount of lateral reinforcement results in a significant improvement in both ductility and energy dissipation capacities of columns. R/C columns with sub-tie provide the improved ductility capacity than those with closely spaced lateral reinforcement only. While the load resisting capacity of the high strength R/C columns is higher than the normal strength concrete columns under both an identical ratio of lateral reinforcement, however the ductility capacity of high strength R/C columns is decreased considerably. Therefore, the amounts of lateral reinforcement must be designed carefully to secure the sufficient ductility and economic design of HSC columns under higher axial load.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.537-540
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• 1999

The primary objective of this study is to make a contribution to the construction of 40~60 story R/C high rise building by developing the reinforcing details which can improve the seismic performance of high-strength (f'c=700kg/$\textrm{cm}^2$, fy=4000, 8000kg/$\textrm{cm}^2$) R/C beam-column joints. And the purpose of this study is to investigate experimentally the effect of load history on the total energy dissipation capacity of reinforced concrete flexural members. The reinforcing details which can make beam plastic hinging zones moved and spreaded from the column face is proposed to insure the ductile behavior of high-strength RC beam-column joints. The intermediate reinforcement which is horizontally anchored by interlinking each intermediate reinforcements is proposed and tested to examine the mechanical performance of proposed details. Main variables are the shape of the intermediate reinforcements and yield strength of rebars. From the test results, the newly proposed intermediate reinforcement details can move and spread the beam plastic hinging zone about 1.0d from the column face.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.547-552
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• 1999

The purpose of this study is to make a contribution to the construction of 40∼60 story R/C high rise building by developing the reinforcing details which can improve the seismic performance of high-strength (f'c=700㎏/㎠, fy=4000, 8000㎏/㎠) R/C beam-column joints. The reinforcing details which can make beam plastic hinging zones moved and spreaded from the column face is proposed to insure the ductile behavior of high-strength RC beam-column joints. The intermediate reinforcement which is vertically anchored by interlinking each intermediate reinforcements is proposed and tested to examine the mechanical performance of proposed details. Main variables are the shape of the intermediate reinforcements and yield strength of rebars. From the test results, the newly proposed intermediate reinforcement details can move and spread the beam plastic hinging zone about 1.0d from the column face.

• 콘크리트학회지
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• 제7권4호
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• pp.169-179
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• 1995

본 논문은 고강도 콘크리트($f'_c=700kg/cm^2$)를 사용한 보_기둥 접합부의 소성힌지 확산을 위하여 중간철근을 수직으로 앵커한 수직앵커형 중간철근으로 보 단부를 보강함으로써 보_기둥 접합부에 발생하는 소성힌지를 보 내측으로 1.0d 만큼 확산시키고자 하는 것이다. 실험의 주 변수로는 중간철근의 유물 및 앵커여부로 설정하여 중간철근의 보강형태에 따른 부재의 역학적 거동을 규명하도록 하였다. 실험결과로부터 보 단부의 1.0d부분을 수직앵커형 중간철근으로 보강하면 소성힌지를 1.0d 부분으로 확산할 수 있었으며, 에너지 분산능력도 ACI318-89에 따라 설계한 관례적인 실험체에 비하여 약 1.6배정도 향상되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.507-512
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• 1998

An experimental investigation was conducted to examine the behavior of high strength R/C columns subjected to reversed cyclic and axial loads and to find the relationship between amounts of lateral reinforcement and axial loads ratios. The test parameters of column specimens were the compressive strength of concrete($f`_c$=250, 320, 460, $517kg/\textrm{cm}^2), $ the yield strength of longitudinal steel($f_y$=3700, $5254kg/\textrm{cm}^2), $ axial load ratio(0.3, 0.5, 0.6$f`_cA_g$). The results indicated that axial load can significantly affect and alter the behavior of HS R/C column under inelastic cyclic loadings. Also we found that the relationship between amounts of lateral reinforcement and axial load ratios was $\rho$ =(0.37η+0.15)f`/f.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.505-508
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• 1999

To evaluate the strength of square reinforced concrete shot columns, thirty specimens were manufactured and tested under monotonically increasing concentric compression. The test parameters included the volumetric ratio of transverse reinforcement($\rho$h = 0.49~2.65), and concrete compressive strength (234, 437, 704 kgf/$\textrm{cm}^2$). Test results are shown that : (1) Behavior of high -strength concrete column is improved by providing increased volumetric ratio; and (2) ACI, Eq. is not proper to evaluate HSC short column strength.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.533-536
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• 1999

The primary purpose of this study is to investigate experimentally the effect of steel fiber reinforcement on the total energy dissipation capacity of R/C flexural members and to make a contribution to the construction of 40~60 story R/C high rise building by developing the new materials and reinforcing details which can improve the seismic performance of high-strength R/C beam-column joints. Experimental research was carried out on 4 type specimen under cyclic loading. Main variables are steel fiber reinforcement, intermediate reinforcements and yield strength of rebars. From the test results, steel fiber reinforcement can improve the ductility of R/C flexural members.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.157-162
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• 2003

An experimental investigation was conducted to study the behavior of high-strength RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were compressive strength of concrete($f_ck$=285, 460kgf/$cm^2$), the ratio of the column-to-beam flexural capacity($M_r$=$\Sigma M_c / \Sigma M_b$ ; 0.77 -2.26), extended length of the column concrete($l_d$ ; 0, 12.5, 30cm), ratio of the column-to-beam width(b/H ; 1.54, 1.67). Test results are shown that (1) the behavior of specimen using high-strength concrete satisfied for required minimum ductile capacity according to increase the compressive strength, (2) the current design code and practice for interior joints(type 2) are apply to the wide beam-high strength concrete column.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.53-58
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• 1992

This research is related to the experimental investigation of the inelastic behavior of R/C columns with high strength concrete. A total of eight specimens have been tested with different span ratios, steel reinforcements and load applications. Through tests bending moments were applied incrementally while axial forces being kept constantly at 80 tons. Careful observation were given to initial crack formation, crack patterns and propagation paths. Comparative studies have been made on the load carrying capacity for R/C columns with high strength concrete versus normal strength concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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• pp.493-498
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• 1998

An experimental investigation was conducted to examine the behavior of high-strength concrete R/C columns subjected to moment, shear and axial load. The test parameters of specimens were the compressive strength of concrete(f'c=250, 516, 600kg/ ㎠), space of lateral reinforcement (20, 30, 37cm) and lateral reinforcement ratio(ρs=2.1, 3.15%). Test results indicated that compressive strength of concrete and lateral reinforcement can significantly affect and alter the behavior of column under inelastic cyclic loadings. Despite of the defaults of high-strength concrete, with increased amount of lateral reinforcement ratio to core concrete and added sub-lateral reinforcement, ductility and strength of RC columns used high-strength concrete can secured.