Simplified design for mechanical connections between precast concrete structural elements in buildings

2019 ◽  
Keyword(s):  
Precast Concrete ◽  
Structural Elements

Connections in Precast Concrete Elements

2016 ◽  
Vol 691 ◽  
pp. 376-387 ◽  
Author(s):  
Ivan Hollý ◽  
Ivan Harvan
Keyword(s):  
Structural Integrity ◽  
Precast Concrete ◽  
Concrete Structures ◽  
Structural Elements ◽  
Entire Structure ◽  
Engineering Department ◽  
Final Design ◽  
Structural Engineer ◽  
Concrete Elements

The structural integrity of precast concrete structures depends mainly on the connections between the precast structural elements. The purpose of a connection is to transfer loads, restrain movement, and/or to provide stability to a component or an entire structure. Therefore, the design of connections is one of the most important aspects in the design of precast concrete structures. All connections should design with valid codes. Every precasters have developed connection details over the years that suit their particular production and erection preferences. It is common, that the structural engineer to show loads and connection locations and allow the successful manufacturer’s engineering department to provide the final design and details of the connections.

scholarly journals STUDI KOMPARASI ANTARA PRACETAK MASIF DAN FLY SLAB STUDI KASUS: STRUKTUR GEDUNG RUSUNAWA SURAKARTA

2018 ◽  
Vol 6 (2) ◽  
pp. 71-80
Author(s):  
Redaksi Tim Jurnal
Keyword(s):  
Comparative Study ◽  
Technological Development ◽  
Concrete Slab ◽  
Precast Concrete ◽  
Reduction Reaction ◽  
Structural Elements ◽  
Conventional Concrete ◽  
Style Transfer ◽  
Central Java ◽  
Concrete Plate

Fly slab is one of the precast concrete slab technological development that has been researched and patented by Ir . Sulistyana in 2011. The concept is how to reduce the mass of precast concrete slab with makes ribs on the concrete slab. To minimize the volume of concrete plate and while maintaining tensile area to makes the style transfer mechanism of concrete to reinforcement or otherwise, are expected to reduce the mass of the structure without reducing strength. Comparative study will be conducted in this research based on Planning of Building Construction Rusunawa in Surakarta, Central Java. This comparative study is done by compare the results of the structural design Rusunawa existing Surakarta and ready to build using conventional precast concrete massive, with a new structure plan Rusunawa Surakarta with using fly slab as material plate, beam and column structural elements using conventional concrete. Based on the analysis results, showed reduction in the volume of concrete and reinforcement elements beam and coloumn Rusunawa Surakarta structure is 20,25% and 6,3 %. Reduction reaction in the vertical structure of the Rusunawa Building in Surakarta is 16,93%.

Seismic performance evaluation of a precast concrete structure with deformation-based limit criterions

2021 ◽  
Vol 4 (3) ◽  
pp. 140-150
Author(s):  
Sadık Can Girgin ◽  
Cem Göksoy ◽  
Emine Daş ◽  
İbrahim Serkan Mısır
Keyword(s):  
Performance Evaluation ◽  
Precast Concrete ◽  
Time History ◽  
Engineering Practice ◽  
Structural Elements ◽  
Performance Limits ◽  
Seismic Evaluation ◽  
Reinforcing Bar ◽  
Evaluation Approach ◽  
Significant Difference

In precast reinforced concrete buildings, which constitute an important part of the industrial buildings in Turkey, the force flow between the structural elements is provided by beam-column connections with or without transferring moments. In general, moment resisting beam-column connections with mechanical or emulative components are applied at the mezzanine level. For precast concrete structures, strength-based design is the most common design approach in engineering practice. In recent years, performance based seismic design and evaluation approach also gained attention which provides numerical estimation of the damage in structural elements subjected to earthquake loading. This study presents the performance based seismic assessment of a two-story precast building based on the seismic evaluation requirements of Turkish Building Earthquake Code 2018. For this purpose, numerical simulation model has been established by using lumped plasticity models for connections and distributed plasticity models for columns. Strong ground motion records are scaled based on TBEC-2018 acceleration spectrum for a specific location, and nonlinear time history analyses are performed in x and y directions simultaneously. The performance evaluation results using average deformations show that there is a significant difference between plastic rotation and reinforcing bar strain performance limits.

scholarly journals Contribution to assessing the stiffness reduction of structural elements in the global stability analysis of precast concrete multi-storey buildings

2012 ◽  
Vol 5 (3) ◽  
pp. 316-342 ◽  
Author(s):  
M. C. Marin ◽  
M. K. El Debs
Keyword(s):  
Global Stability ◽  
Structural Model ◽  
Precast Concrete ◽  
Bending Moments ◽  
Structural Elements ◽  
Technical Literature ◽  
Stiffness Reduction ◽  
Reduction Coefficient ◽  
Negative Bending ◽  
Raphson Method

This study deals with the reduction of the stiffness in precast concrete structural elements of multi-storey buildings to analyze global stability. Having reviewed the technical literature, this paper present indications of stiffness reduction in different codes, standards, and recommendations and compare these to the values found in the present study. The structural model analyzed in this study was constructed with finite elements using ANSYS® software. Physical Non-Linearity (PNL) was considered in relation to the diagrams M x N x 1/r, and Geometric Non-Linearity (GNL) was calculated following the Newton-Raphson method. Using a typical precast concrete structure with multiple floors and a semi-rigid beam-to-column connection, expressions for a stiffness reduction coefficient are presented. The main conclusions of the study are as follows: the reduction coefficients obtained from the diagram M x N x 1/r differ from standards that use a simplified consideration of PNL; the stiffness reduction coefficient for columns in the arrangements analyzed were approximately 0.5 to 0.6; and the variation of values found for stiffness reduction coefficient in concrete beams, which were subjected to the effects of creep with linear coefficients from 0 to 3, ranged from 0.45 to 0.2 for positive bending moments and 0.3 to 0.2 for negative bending moments.

scholarly journals Development of Novel Connections for Pre-cast Composite and Pre-cast Concrete Frames

2015 ◽  
pp. 397-404
Author(s):  
J.D Nzabonimpa ◽  
Won-Kee Hong ◽  
Seon-Chee Park ◽  
Sunkuk Kim
Keyword(s):  
Precast Concrete ◽  
Steel Plates ◽  
Structural Elements ◽  
Structural System ◽  
Concrete Frames ◽  
Structural Behaviour ◽  
Moment Connections ◽  
Composite Frame ◽  
Structural Capacity ◽  
Cast Concrete

In some applications, the conventional steel pipe racks were encased with concrete to protect the frame from fire. However, the concrete encasing steel is not considered to contribute to structural capacity at all. This paper proposed pipe rack frames encased by precast concrete, but with functions both as a part of structural elements contributing to flexural load bearing capacity and to fire proofing. The new steel-concrete composite structural system consisting of steel, concrete with reinforcements, extended steel plates with bolts designed based on inelastic finite element method provides efficient structural performances, reducing material quantities with the protection from fires. Additionally extended plate with bolts introduced for column-beam joint assembly played important roles in providing moment connections. AISC 358 introduced the use of extended plate similar to the proposed connection. Significant experimental and analytical investigations were performed to verify structural behaviour of the composite frame. Material quantities were also compared to demonstrate economy of the new frames compared with conventional pipe rack frames.

scholarly journals Fatigue and fracture mechanical properties of selected concrete for subtle precast structural elements

2020 ◽  
Vol 310 ◽  
pp. 00033
Author(s):  
Stanislav Seitl ◽  
Petr Miarka ◽  
Vlastimil Bílek
Keyword(s):  
Mechanical Properties ◽  
Precast Concrete ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Structural Elements ◽  
Mechanical Fracture ◽  
Fatigue And Fracture ◽  
Natural Aggregates ◽  
Concrete Elements ◽  
Bearing Part

Precast concrete elements used as a civil structure are usually made of a cement-based matrix and natural aggregates (such as sand, gravel, crushed stone, etc.). These structures are usually exposed not only to a static load but also to a cyclic load if they load the bearing part of a bridge (traffic etc.). The knowledge of fatigue and fracture mechanical characteristics is important in designing and modelling new structures. This paper introduces and compares fracture mechanical properties obtained from static and fatigue tests for three kinds of concrete. The focus was set on the bulk density, flexural and compressive cube strength, fracture toughness and fatigue properties (S−N − Wöhler curve). All of these tests are important for a practical application in the design of precast concrete structures. The experimental results were statistically analysed and they showed that the fatigue and mechanical fracture properties improved with improved mechanical parameters of concrete.

Prefabricated Bridge Elements and Systems in Japan and Europe

2005 ◽  
Vol 1928 (1) ◽  
pp. 102-109 ◽  
Author(s):  
Henry G. Russell ◽  
Mary Lou Ralls ◽  
Benjamin M. Tang
Keyword(s):  
Precast Concrete ◽  
Work Zone ◽  
Bridge Piers ◽  
Life Cycle Costs ◽  
Structural Elements ◽  
Concrete Panels ◽  
Work Zone Safety ◽  
Construction Methods ◽  
Short Time ◽  
Concrete Deck

In April 2004, a scanning tour of Japan, the Netherlands, Belgium, Germany, and France was made to obtain information about bridge construction methods being used to minimize traffic disruption, improve work zone safety, minimize environmental impact, improve constructibility, increase quality, and lower life-cycle costs. From information obtained from the tour, 10 technologies were identified for further consideration and possible implementation into U.S. practices. These included two technologies that allow bridges to be built off site and then moved to their final location in a short time, three superstructure systems and four deck systems that facilitate faster and safer construction, and one substructure system. The two technologies for moving bridges were self-propelled modular transporters and other moving systems, including skidding or sliding, incremental launching, floating, rotating, and lifting of bridges into place. The superstructure systems included a precast concrete deck system known as the Poutre Dalle system, the use of partial-depth concrete decks prefabricated on steel or concrete beams, and U-shaped precast concrete segments with transverse ribs. The deck systems involved full-depth prefabricated concrete decks, special cast-in-place closure joint details, hybrid steel–concrete deck systems, and a multiple-level corrosion protection system. The substructure system consisted of stay-in-place precast concrete panels that serve as both formwork and structural elements for solid and hollow bridge piers.

scholarly journals INSTABILIDADE LATERAL DE VIGAS PRÉ-MOLDADAS DE CONCRETO: INFLUÊNCIA DA EXCENTRICIDADE LATERAL INICIAL E POSICIONAMENTO DAS ALÇAS DE IÇAMENTO [ Lateral Instability of precast concrete beams: influence of lateral instability eccentricity and positioning of lifting handles ]

2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Igor Gabriel Ribeiro Cardoso Evangelista ◽  
Maria Cristina Vidigal de Lima
Keyword(s):  
Cross Section ◽  
Concrete Beams ◽  
Precast Concrete ◽  
Favorable Effect ◽  
Structural Elements ◽  
Lateral Instability ◽  
Critical Situation ◽  
Numerical Studies ◽  
Transitory Phase ◽  
Steel Cables

RESUMO: O estudo da instabilidade de vigas pré-moldadas de concreto tem merecido maior atenção devido aos preocupantes acidentes registrados com a ruptura de vigas por instabilidade lateral. A importância do estudo deve ser considerada além da fase de montagem, mas também durante o transporte e içamento. A geometria da viga influencia diretamente no problema de instabilidade, por se tratar de elementos estruturais longos e esbeltos. Neste contexto, este trabalho analisa numericamente o comportamento estrutural de vigas durante a fase de içamento por meio de cabos de aço, levando-se em conta a excentricidade lateral inicial e o posicionamento dos cabos de suspensão, considerando o comprimento dos balanços e os desvios de posicionamento das alças na seção transversal. Assim, para vigas com seção transversal I padronizadas são calculados os deslocamentos, tensões e ângulos de giro para diferentes comprimentos de balanço e desvios laterais das alças. Os resultados dos estudos numéricos mostram que as condições de içamento são mais seguras quando o manuseio é realizado com balanços e com alças no sentido contrário à curvatura. Além disso, deve-se observar o efeito favorável decorrente do aumento da altura da mesa inferior, deslocando para baixo o centro de gravidade do elemento estrutural, favorecendo o equilíbrio, chegando a 15% de redução nos deslocamentos e tensões, e diminuição de até 25% no valor da rotação da viga, na situação mais crítica sem balanços e com desvios desfavoráveis das alças de içamento. O aumento da excentricidade lateral inicial deve ser observado com cautela, podendo provocar acréscimos de tensões de até 30%, nos casos críticos sem balanços.ABSTRACT: The study of the instability of precast concrete beams has deserved more attention due to concerning accidents with beam rupture by lateral instability. The importance of the study should be considered beyond the transitory phase, but also transportation and lifting. The geometry of the beam influences directly in instability problem, due to long and slender structural elements. In this context, this research analyzes, numerically, the structural behavior of beams during the lifting phase by steel cables, taking into account the initial lateral eccentricity and positioning of the suspension cables, considering the length of the balances and the positioning deviations of the handles in the cross-section. Thus, for beams with standardized cross-section I, displacements, stresses and angles of rotation for different balance lengths and lateral deviations of the handles are evaluated. The results of the numerical studies show that lifting conditions are safer when the handling is performed with balances and with handles in the opposite direction to the curvature. Furthermore, the favorable effect of dislocating down the center of gravity reduces by 15% the displacements and tensions, and induces a decrease up to 25% in the value of the rotation of the beam, in the most critical situation without balances and with unfavorable deviations of the lift loops. The increase in the initial lateral eccentricity should be observed with caution, which may increase tensions up to 30% in critical cases without balances.

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