• Title/Summary/Keyword: RC flat slab

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The Numerical Analysis of Heavy Weight Impact Noise for an Apartment House (공동주택 모델링을 통한 중량충격음 예측에 관한 연구)

  • Hwang, Jae-Seung;Moon, Dae-Ho;Park, Hong-Gun;Hong, Sung-Gul;Hong, Geon-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.2
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    • pp.162-168
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    • 2009
  • In this study, numerical analysis is performed to investigate the sound radiation characteristics of an apartment house according to the type of the slab system. In order to satisfy the boundary condition of the apartment house, the whole floor is modelled with FEM model for three different structural system: wall, RC, flat slab system. From the analytical results, it is shown that heavy weight floor impact noise of wall type slab is larger than that of the other slab systems and the noise radiated from the wall have great effect on the sound pressure level. The results also show that the vibration energy of RC or flat slab system is widely distributed over the whole slab, which is main reason that the noise induced by the slab systems is reduced in comparison with wall slab system.

Parametric studies on punching shear behavior of RC flat slabs without shear reinforcement

  • Elsamak, Galal;Fayed, Sabry
    • Computers and Concrete
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    • v.25 no.4
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    • pp.355-367
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    • 2020
  • This paper proposed a numerical investigation based on finite elements analysis (FEA) in order to study the punching shear behavior of reinforced concrete (RC) flat slabs using ABAQUS and SAP2000 programs. Firstly, the concrete and the steel reinforcements were modeled by hexahedral 3D solid and linear elements respectively, and the nonlinearity of the used materials was considered. In order to validate this model, experimental results considered in literature were compared with the proposed FE model. After validation, a parametric study was performed. The parameters include the slab thickness, the flexure reinforcement ratios and the axial membrane loads. Then, to reduce the time of FEA, a simplified modelling using 3D layered shell element and shear hinge concept was also induced. The effect of the footings settlement was studied using the proposed simplified nonlinear model as a case study. Results of numerical models showed that increase of the slab thickness by 185.7% enhanced the ultimate load by 439.1%, accompanied with a brittle punching failure. The punching failure occurred in one of the tested specimens when the tensile reinforcement ratio increased more than 0.65% and the punching capacity improved with increasing the horizontal flexural reinforcement; it decreased by 30% with the settlement of the outer footings.

Study on Stress Variation in Slab and Support of Shearwall-Type RC Apartment during Construction (전단벽식 아파트에서 시공중 슬래브 및 동바리의 응력변화에 대한 연구)

  • Kim Young-Chan
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.161-165
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    • 2004
  • Safety and efficiency in the construction of RC structures mainly depends on optimal operation of shore-slat systems. The disasters in RC construction are mainly due to excessive load applied to falsework and premature removal of supports. Development of sufficient compressive strength of early-age connote is essential for the safety of structures during construction. Most of studies on shore-slab interaction have focused on flat slab structures. In this study, load distributions in floor slabs and supports during the construction of shear wall-type RC apartment building structures is investigated using finite element analysis.

Design and Construction of Flat Slab using Unbonded Post-tension System (비부착 포스트텐션 플랫 슬래브의 설계와 시공)

  • Chung, Kwang-Ryang;Park, Jung-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05b
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    • pp.91-96
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    • 2011
  • The flat slab is well-known as a structural system to reduce the story height, so it is broadly used for recent building. However, the normal RC flat slab is not appropriate for the long span, and the quantity of reinforcement bar and concrete is raised. Recently, the post-tensioning system has been introduced and used widely as an alternative method. Nevertheless, in Korea, it is not used broadly due to lack of the understanding and field experience. Especially, the post-tensioning system is hesitated to use due to uncertainty of construction ability and economics. This paper will introduce applicability to site and economics of unbonded post-tensioning system through construction examples.

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Lateral Resisting Capacity for CFT Column to RC Flat Plate Slab Exterior Connections (CFT 기둥-RC 무량판 슬래브 외부접합부의 횡저항 성능)

  • Song, Ho-Beom;Song, Jin-Kyu;Oh, Sang-Won;Kim, Byung-Jo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.61-64
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    • 2008
  • A combination of CFT column and RC flat plate without formworks is very effectively rapid constructions. This paper verified the lateral resisting capacity of CFT column-RC flat plate exterior connection in comparison with general RC column-flat plate connection and detected moment capacity and ductility capacity of connection according to moment-displacement ratio. We made and tested specimens which have different variables respectively and as a result derive a following conclusion. In CFT-E2 specimen a critical section was extended and maximum moment increased 20% respectively in comparison to general RC column specimen. In BME and CFT-E1 specimens generally shear governed behaviors and CFT-E2 specimen complemented with seismic band, flexure behavior region of slab was extended and also ductility ratio and energy absorptance increased.

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Modeling Method of Slabs in RC Flat-Plate Structures Under Lateral loading (횡하중을 받는 RC 무량판 구조의 슬래브 모델링 기법)

  • 최정욱;송진규;이수곤;김진상
    • Journal of the Korea Concrete Institute
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    • v.14 no.4
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    • pp.615-622
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    • 2002
  • To reasonably predict the behaviors for RC flat-plate structures, analysis model considering the flexural stiffness of slabs is required. FEMA 273 and ACI 318-99 refer to theoretical analysis models of two-way slab systems under lateral loading but the actual application method is not suggested. In this study, the modeling and application methods of the flat-plates using effective beam concept are suggested. The results of this study are as follows. 1) The effective beam width model suggested in this study is very useful to model flat-Plate structures subjected to seismic loading for three dimensional analysis 2) The result of analysis for idealized flat-plate example using the effective beam widths considering the effect of the slab crack is shown upper value for displacements. Whereas the model considering effective beam width coefficients only is shown upper value for unbalanced moments

Evaluation of Lateral Performance in RC Flat Plate System (철근콘크리트 무량판 구조시스템의 횡저항 성능 평가)

  • Song, Ho-Bum;Song, Jin-Gyu
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.151-158
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    • 2006
  • Recently, as RC flat plate system is applied on high-rising building largely, necessity of all over research about lateral performance becomes a prominent. In this paper, It is estimated that performance of slab-column connection in flat plate system is inter-story drift index 3.6%. In addition, when R-factor is fixed in seismic design, it must be considered all system. Also Considering that plastic hinge propagation is not adjustable, R-factor should be applied bellow '5.5'.

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Economics on Structural Floor Systems of Super Tall Buildings

  • Shin Sung-Woo;Ahn Jong-Moon;Choi Myung-Shin;Seo Dae-Won;Kim Chul
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.609-613
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    • 2004
  • An economic analysis is one of the most dominant factors to determine the project feasibility of super tall building. In economic considerations, it is very important toadopt optimum structural floor systems because these are dependent on both the cost and the duration of construction. The economics affected by structural floor systems are more distinct athigher story. As the story increases, the construction cost of floor system. is accumulated linearly, while the cost of lateral resisting system is increased geometrically. The purpose of this study is to investigate the economical effects of super tall buildings through application of optimum structural floor systems. Three types of structural systems(RC beam-column frame, RC flat plate frame, and Steel frame) of super tall buildings having 50-stories are considered in this study and compared to RC flat plate slab with other systems. Analytical result shows that RC flat plate slab using lightweight concrete ismost effective in both the cost and the duration of construction.

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Simulations of short- and long-term deflections of flat plates considering effects of construction sequences

  • Kim, Jae-Yo;Kang, Su-Min
    • Structural Engineering and Mechanics
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    • v.62 no.4
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    • pp.477-485
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    • 2017
  • The structural designs of RC flat plates that have no flexural stiffness by boundary beams may be governed not by strength conditions but by serviceabilities. Specially, since over-loading and tensile cracking in early-aged slabs significantly increase the short- and long-term deflections of a flat plate system, a construction sequence and its impact on the slab deflections may be decisive factors in designs of flat plate systems. In this study, the procedure of simulating slab deflections with considering construction sequences, concrete cracking, and long-term effects is proposed. The proposed method is practically useful, as it can predict well the slab deflections at construction and service stages only with a few input data. The proposed method is verified by comparisons with measured results in a real-scale test.

Lateral Resisting Capacity for CFT Column to RC Flat Plate Slab Connections (CFT 기둥 - RC 무량판 슬래브 접합부의 횡저항 성능)

  • Song, Jin-Kyu;Song, Ho-Beom;Oh, Sang-Won;Lee, Cheol-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.65-68
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    • 2008
  • This paper verified the lateral resisting capacity of CFT column-RC flat plate connection in comparison with general RC column-flat plate connection and detected moment capacity and ductility capacity of connection according to lateral force-displacement ratio. We made and tested specimens which have different variables respectively and as a result derive a following conclusion. In CFT specimen a critical section was extended and initial stiffness and moment increased 35%, 25$^{\sim}$35% respectively in comparison to general RC column specimen. In all specimens generally shear governed behaviors and in CFT specimen complemented with seismic band, flexure behavior region of slab was extended and also ductility ratio and energy absorptance increased.

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