• Title/Summary/Keyword: Slab Design

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Contribution of Reinforced Concrete Floor Slabs to Lateral Behavior of Tall Buildings

  • Rehmanjee, Yasmin;Leslie, Benjamin;Lamianski, Dmitri;Chafart, Manuel
    • International Journal of High-Rise Buildings
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    • v.11 no.1
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    • pp.25-29
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    • 2022
  • This paper focuses on how the coupling of the columns and walls through the structural slab contributes to the overall stiffness and strength of lateral systems. The rationale and procedures behind the design approach, which may offer a shift from more conventional assumptions made regarding compatibility and connectivity of gravity and lateral structural systems, will be introduced. The impacts on serviceability and strength design will be discussed, and observations on key design and analysis approaches will be featured. Mass and stiffness assumptions will also be reviewed. A case study on the topic will be presented describing implementation of slab coupling into engineering of a building project.

A thermal stress and crack study by computer modelling (전산해석에 의한 온도응력 및 온도균열 검토)

  • 문수동;이상호;문한영
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.375-380
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    • 2002
  • Tong-young LNG tank is a LNG storage tank of 140,000 kl, and it is composed of Bottom Slab(Annular, Center), Outer Wall, Ring Beam and Roof. Generally, when concrete temperature arise, the complex thermal stress of inner and outer part can cause serious thermal crack and damage at structure. So in this paper, for the control of this thermal crack, we did the concrete mix design with the base of fly-ash 30% substitute at binder, and through the computer modelling at Bottom Slab(Annular, Center), Outer Wall, Ring Beam and Roof, we studied the probability of thermal crack by thermal crack index.

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A Study on Span to Depth Ratio for Minimum Thickness of One-Way Slab

  • Choi, Bong-Seob;Kwon, Young-Wung
    • KCI Concrete Journal
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    • v.11 no.3
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    • pp.45-52
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    • 1999
  • A Computer-based iterative method is provided for the calculation of minimum thickness values for one-way slabs to satisfy the maximum permissible limits given in the ACI Building Code. An algorithm includes the effects of cracking and time-dependent effects due to creep and shrinkage. Comparison of the calculated minimum thickness values with the current ACI limits is conducted to investigate limitations of the current tabulated minimum thickness. which are constant to a range of design conditions.

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Numerical modeling of an orthotropic RC slab band system using the Barcelona model

  • Kossakowski, Pawel G.;Uzarska, Izabela
    • Advances in Computational Design
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    • v.4 no.3
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    • pp.211-221
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    • 2019
  • Numerical modeling of reinforced concrete structures is a difficult engineering problem, primarily because of the material inhomogeneity. The behaviour of a concrete element with reinforcement can be analyzed using, for example, the Barcelona model, which according to the literature, is one of the most suitable models for this purpose. This article compares the experimental data obtained for an orthotropic concrete slab band system with those predicted numerically using Concrete Damage Plasticity model. Abaqus package was used to perform the calculations.

Numerical Analysis of Curling Behavior of Prestressed Approach Slab Subjected to Environmental Loads (환경하중에 의한 교량 프리스트레스 접속슬래프의 컬링 거동 수치 해석적 분석)

  • Park, Hee-Beom;Eum, In-Sub;Kim, Seong-Min;Rhee, Suk-Keun
    • International Journal of Highway Engineering
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    • v.13 no.3
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    • pp.7-14
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    • 2011
  • The numerical analyses were performed to investigate the curling behavior of the post-tensioned prestressed concrete approach slab (PTAS) under environmental loads. A technique to include properly the boundary conditions of one end of PTAS that was connected to the bridge abutment using hinges was proposed for the numerical model. The applicability of a simplified model not having hunches was also investigated. By using the developed models, the curling behavior of PTAS was analyzed when the foundation settlement occurred. The analysis results showed that the maximum tensile stress obtained from the simplified model involving a simplified hinge connection was very closed to that obtained from a rigorous model. When the slab curled up, the maximum tensile stress occurred in the model including no foundation settlement, but when the slab curled down, the maximum stress occurred in the model including partial settlement of the foundation. Therefore, the design of PTAS should be performed considering those maximum tensile stresses.

Determination of Equivalent Vehicle Load Factors for Flat Slab Parking Structures Using Artificial Neural Networks (인공 신경망을 이용한 플랫 슬래브 주차장 구조물의 등가차량하중계수)

  • 곽효경;송종영
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.2
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    • pp.115-124
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    • 2003
  • In this paper, the effects of vehicle loads on flat slab system are investigated on the basis of the previous studies for beam-gilder parking structural system. The influence surfaces of flat slab for a typical design section are constructed lot the purpose of obtaining maximum member forces under vehicle loads. In addition, the equivalent vehicle load factors for flat slab parking structures are suggested using artificial neural network. The network responses we compared with the results obtained by numerical analyses to verify the validation of Levenberg-Marquardt algorithm adopted as training method in this Paper. Many parameter studies for the flat slab structural system show dominant vehicle load effects at the center positive moments in both column and middle strips, like the beam-girder parking structural system.

Shear Strength Model for Slab-Column Connections (슬래브-기둥 접합부에 대한 전단강도모델)

  • Choi, Kyoung-Kyu;Park, Hong-Gun;Kim, Hye-Min
    • Journal of the Korea Concrete Institute
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    • v.22 no.4
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    • pp.585-593
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    • 2010
  • On the basis of the strain-based shear strength model developed in the previous study, a strength model was developed to predict the direct punching shear capacity and unbalanced moment-carrying capacity of interior and exterior slab-column connections. Since the connections are severely damaged by flexural cracking, punching shear was assumed to be resisted mainly by the compression zone of the slab critical section. Considering the interaction with the compressive normal stress developed by the flexural moment, the shear strength of the compression zone was derived on the basis of the material failure criteria of concrete subjected to multiple stresses. As a result, shear capacity of the critical section was defined according to the degree of flexural damage. Since the exterior slab-column connections have unsymmertical critical sections, the unbalanced moment-carrying capacity was defined according to the direction of unbalanced moment. The proposed strength model was applied to existing test specimens. The results showed that the proposed method predicted the strengths of the test specimens better than current design methods.

Effect of the spandrel end beams on shear strength behavior in MTS systems (MTS (Multi-tee slab) 시스템의 테두리보가 전단 강도에 미치는 영향)

  • Kim, Min-Ki;Hong, Sung-Gul;Lee, Jong-Min;Cho, Yi-Hoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.189-192
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    • 2008
  • Most existing double tee systems have need to improve flexure and shear design at their flanges in the section. In order to solve this problem we have devised MTS(Multi-tee slab) system, which is composed of several T-beams and applied spandrel end beams at each slab unit. The application of spandrel end beams has an beneficial effect on the shear strength and force distribution of slab unit because they support the ribs in the transverse direction. Numerical analysis shows that the spandrel end beams increase the shear strength. This paper represents the analysis of shear strength in MTS system and the effect of the spandrel end beams on the system.

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The relationship between reinforcing index and flexural parameters of new hybrid fiber reinforced slab

  • Cao, Mingli;Xie, Chaopeng;Li, Li;Khan, Mehran
    • Computers and Concrete
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    • v.22 no.5
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    • pp.481-492
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    • 2018
  • In this paper, a new hybrid fiber system (NHFS) is investigated for the application of slab. The steel fiber, polyvinyl alcohol (PVA) fiber and calcium carbonate ($CaCO_3$) whisker is added to form NHFS. The four-point bending test is carried out on the flexural properties of slab with plain, steel fiber, traditional hybrid fiber system (THFS) and NHFS reinforced cementitious composites. The flexural behavior is evaluated by ASTM C1018-97, JCI-SF4 and post-crack strength (PCS) technique. The evaluation parameters of flexural toughness such as toughness index (TI), equivalent flexural strength (EFS) and PCS are determined. The size of slab specimens is $15mm(thickness){\times}50mm(width){\times}200mm(length)$. The results show that adding $CaCO_3$ whisker to THFS can significantly improve the flexural strength, TI, EFS, PCS of the slab. The empirical relation between reinforcing index ($RI_v$) and flexural parameters show that flexural parameters of slabs increase first and then decrease; which indicates that optimum $RI_v$ values can be helpful in the considering the mix design of steel-PVA fibers-$CaCO_3$ whisker composites for achieving the desired flexural-related properties. The scanning electron microscopy is performed to observe the micro-morphological characteristics of the fracture surface, which proved the positive hybrid effect among the different fibers in cementitious composites. The NHFS can arrest the generation and propagation of the crack from micro to macro level.