• Title/Summary/Keyword: ACI 349

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The Method for Determining the Effectiveness Factor(k value) of Concrete Expansion Anchors in accordance with ACI 355.2 (ACI 355.2에 의한 콘크리트 확장앵커의 유효계수(k값) 결정방법)

  • Lee, Byung Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.151-152
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    • 2020
  • Recently, concrete expansion anchors which are a type of post-installed mechanical anchors are widely used in reinforcement concrete structures. In order to be used in the reinforced concrete structures designed in accordance with ACI 318-19 or ACI 349-13, the structural performance tests of the concrete expansion anchors should be conducted in accordance with ACI 355.2. The effectiveness factor(k) of concrete expansion anchors should be determined through the reference tests and used for the design of anchorage to concrete according to ACI 318-19 or ACI 349-13. In this study, we will look into the method for determining the effectiveness factor(k) of concrete expansion anchors and anchorage design process of concrete expansion anchors by using the effectiveness factor(k) in accordance with ACI 349-19.

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An Evaluation of ACI 349 Code for Shear Design of CIP Anchor (직매형 앵커기초의 전단설계를 위한 ACI 349 Code의 평가)

  • Jang Jung-Bum;Hwang Kyeong-Min;Suh Yong-Pyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.464-470
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    • 2005
  • The numerical analysis is carried out to identify the influence of design factors to shear capacity of cast-in-place (CIP) anchor in ACI 349 Code that is available for the design of fastening system at Nuclear Power Plant (NPP) in this study. The MASA program is used to develop the numerical analysis model and the developed numerical analysis model is verified on a basis of the various test data of CIP anchor. Both $l/d_o$ and $c_1/l$ we considered as design factors. As a result, the variation of $l/d_o$ has no influence on the shear capacity of CIP anchor but $c_1/l$ has a large influence on the shear capacity of CIP anchor, Therefore, it is proved that ACI 349 Code may give a non-conservative results compared with real shear capacity of CIP anchor according to $c_1/l$.

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Fracture Behavior of CIP Anchor in Cracked Concrete (균열 콘크리트 면에서의 CIP앵커의 파괴거동)

  • 김호섭;윤영수;윤영수;박성균
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.169-174
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    • 2001
  • This study concerns crack effect on concrete anchor system and prediction of tensile capacity, as governed by concrete cone failure, of single anchors located at center of concrete specimen. To Investigate crack effect three different types of crack such as crack width of 0.2mm and 0.5nm, crack depth of loom and 20cm, and crack location of center and biased point were simulated. The static tensile load was subjected to 7/8 in. CIP anchor embedded in concrete of strength 280kg/$cm^{2}$. Tested pullout capacity was compared to prediction value by each current design method (such as ACI 349-97, ACI 349 revision and CEB-FIP which is based on CC Method), In these comparison CC Method and ACI revision showed almost same value in uncracked concrete specimen, however in cracked concrete CC Method showed conservativeness. Therefore the design by ACI 349 revision is recommended for the safe and economic design.

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Headed Bar Anchorage of Exterior Beam Column Joints in Nuclear Power Plants (원전구조물의 외부 보기둥 접합부에서 철근 기계적 정착)

  • Chun, Sung-Chul;Lee, Sung-Ho;Oh, Bo-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.42-45
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    • 2006
  • This study investigated headed bar anchorage of exterior beam column joints in nuclear power plants. In nuclear power plant structures, anchorage of headed bar is recommended to satisfy ACI 349-01 App. B that are based on the Concrete Capacity Design (CCD) method. However, CCD method may lead to very conservative results for beam column joints where head is anchored within the diagonal strut and concrete is confined by transverse rebar. Compared with results of 5 joint specimens, the anchorage capacities calculated by ACI 349-01 are underestimated by 70-90%. Therefore, it is necessary to amend ACI 349-01 for the mechanical anchorage in beam column joints.

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ACI 349 Code Change to Use the Gr.80 Headed Deformed Bars in Nuclear Power Plant Structures (Gr.80 확대머리철근의 원전구조물 적용을 위한 ACI 349 코드개정에 관한 연구)

  • Lee, Byung Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.200-201
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    • 2017
  • Generally, a lot of reinforcements are used in nuclear power plant concrete structures, and it may cause several potential problems when concrete is poured. Because of the congestion caused by hooked bars, embedded materials, and other reinforcements, it is too difficult to pour concrete into structural member joint area. The purpose of this study is to change ACI 349 Code for using the large-size(57mm) and high-strength(Gr.80) headed deformed bars instead of standard hooked bars in nuclear power plant concrete structures in order to solve the congestion problems.

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Assessment of Fracture Behaviors for CIP Anchors Fastened to Cracked and Uncracked Concretes

  • Yoon, Young-Soo;Kim, Ho-Seop;Kim, Sang-Yun
    • KCI Concrete Journal
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    • v.13 no.2
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    • pp.33-41
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    • 2001
  • This paper presents the crack effect on CIP anchors and prediction of tensile capacity, as governed by concrete cone failure. Single anchors where located at center of concrete specimen. Three different types of cracks such as crack width of 0.2 mm and 0.5 mm, crack depth of 10 cm and 20cm , and crack location of center and off-center point were simulated. Static tensile load was applied to 7/8-in. CIP anchors of 10 cm and 20 cm embedment length in concrete with compressive strength of 280 kgf/$\textrm{cm}^2$. Tested pullout capacities were compared to the values determined using current design methods (such as ACI 349-97, ACI 349 revision and CEB-FIP which is based on CCD Method). The comparison of CCD Method and ACI revision showed almost the same values in uncracked concrete specimen. In cracked concrete, CCD Method predicted conservative values. Three-dimensional non-linear FEM modeling also has been performed to determine the stresses distribution and crack inclination.

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Cyclic Loading Test for Shear Strength of Low-rise RC Walls with Grade 550 MPa Bars (550 MPa 급 철근을 적용한 낮은 철근콘크리트 벽체의 전단강도를 위한 반복하중 실험)

  • Park, Hong-Gun;Lee, Jae-Hoon;Shin, Hyun-Mock;Baek, Jang-Woon
    • Journal of the Korea Concrete Institute
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    • v.25 no.6
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    • pp.601-612
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    • 2013
  • In the construction of nuclear power plants using massive walls, the use of high-strength re-bars for shear design is necessary to enhance the constructability and economy. In this study, low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars were tested under cyclic loading to investigate the shear capacity and deformation capacity. The test parameters were the grade of horizontal re-bars (550 MPa, 420 MPa), strength of concrete compressive strength (46 MPa, 70 MPa), horizontal/vertical reinforcement ratio, use of lateral confinement hoops, shape of cross section, and failure modes (shear failure before or after flexural yielding). The test results were compared with those of walls with grade 420 MPa bars and predicted strength by current design codes. The results showed that the shear strength of the walls with 550 MPa bars was comparable to that of the walls with 420 MPa bars though the safe margin slightly decreased. ACI 349 provides underestimated shear strength for the walls with 550 MPa bars. In case of the wall with flexural yielding, a large deformation capacity was achieved. This result indicates that the ACI 349 provisions can be safely applied to seismic design of the low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars.

Behavior of Large Sized Anchorage System under Shear Loads (직매형 대형매입앵커의 전단거동특성)

  • Kim, Kang-Sik;Kwon, Ki-Joo;Shin, Sung-Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.87-88
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    • 2009
  • In this research project, 24 tests are performed to find out a behavior and shear breakout capacity of large anchor system exceeding 2 inch(50mm) in anchor bolt diameter($d_0$) and 25 inch(635mm) in effective embedment($h_{ef}$) not addressed by ACI 349-01 Appendix B (ACI 349 2001). On this report, analysis results are presented that this variables influence on behavior and shear breakout strength through those of test results.

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Shear Strength of Single Anchors in Uncracked and Unreinforced Concrete (비균열·무근콘크리트의 단일앵커 전단내력 평가)

  • Kim, Sung-Yong;Kim, Kyu-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.4
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    • pp.171-181
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    • 2003
  • This study concerns the prediction of shear capacity, as governed by concrete breakout failure, concrete pryout failure and steel failure, of single anchors located close to free edge and located far from a free edge and installed in uncracked, unreinforced concrete. For this purpose, the methods to evaluate the shear capacity of the single anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods: the method of ACI 349-90 and concrete capacity design (CCD) method.