scholarly journals MODIFIKASI STRUKTUR GEDUNG DENGAN BETON PRACETAK PADA APARTEMEN THE CONEXIO

2020 ◽  
Vol 2 (2) ◽  
pp. 115-122
Author(s):  
Adita Devania ◽  
Andrias Rudi Hermawan

Abstract  The Conexio Appartements in actual condition are designed using conventional reinforced concrete method and does not have good quality. While in the project also often afected by the weather. The use of precast concrete are having some excellence of them are not affected by the weather, well maintained quality, and earthquake resistant. The connection between the precast elements play an important role in precast buildings to make the buildings resistant to earthquake. This modification is intended to created earthquake resistant precast building  according to SNI 2847:2013 with good quality control. In this study, the building will be modified into 8 floors precast building as planned and reviewed which will be analyzed by ETABS. From the results of the modification according to SNI 1726:2012 and SNI 2847:2013 we obtained, main beam dimension 40x60cm, secondary beam 35x55 cm, column dimension 65x65 cm, overtopping 6 cm for slab and using Splice sleeve grout for column to column connection, lap splices 500mm for beam-column connection, and 30x40cm for concrete consol dimension.Keywords : Precast, Splice Sleeve, Wet Connection.Abstrak Apartemen The Conexio pada kondisi sebenarnya dirancang menggunakan metode konvensional dengan kondisi mutu yang kurang baik. Dalam pelaksanannya, proyek tersebut juga sering terganggu oleh cuaca. Penggunaan beton pracetak memiliki beberapa keunggulan diantaranya pelaksanaannya tidak terpengaruh oleh cuaca, memiliki mutu yang terjaga dan tahan gempa. Sambungan antar elemen pracetak sangat berperan penting dalam bangunan dengan beton pracetak yang tahan gempa sehingga perlu diperhitungkan sesuai dengan peraturan. Modifikasi ini ditujukan untuk menghasilkan gedung dengan pracetak yang tahan gempa sesuai dengan SNI 2847:2013 dengan pengendalian mutu yang baik. Dalam studi ini, gedung tersebut akan dilakukan modifikasi struktur menjadi beton pracetak dengan tinjauan 8 lantai dan analisa dibantu dengan software ETABS. Dari hasil modifikasi yang dilakukan, elemen-elemen pracetak sesuai dengan ketentuan SNI 1726:2012 dan SNI 2847:2013 yaitu meliputi ukuran balok induk 40x60cm, ukuran balok anak 35x55 cm, dengan kolom berdimensi 65x65 cm, tebal overtopping 6 cm pada pelat dan menggunakan Splice sleeve grout pada sambungan kolom, penyambungan balok-kolom dengan panjang penyaluran 500 mm dan penggunaan konsol pada kolom dengan dimensi 30x40cm. Kata kunci  : Beton Pracetak, Splice Sleeve, Sambungan Basah.  

Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.


2019 ◽  
Vol 8 (4) ◽  
pp. 3633-3637

Precast concrete structures are widely used in construction. It consists of prefabricated elements casted in industry and connected to each other to form a homogeneous structure. Connections function is to transfer moments and axial forces. Many engineers assume precast connection as pinned, but in reality, they are semi-rigid connections that transfer forces to other members. Lack of design and detailing of connection leads to improper behaviour of the structure, which then leads to the collapse of the building. Past earthquake studies show that many precast buildings performed poorly, and the main reasons were connections. This paper mainly focuses on understanding the seismic behaviour of mid-rise i.e seven-storey precast reinforced concrete buildings with various beam-column joints i.e rigid, semi-rigid, pinned and column-base supports i.e, fixed and hinged supports. Building is modelled and analyzed using ETABS v17 software. Rotational stiffness of precast billet connection is adopted for modelling of semi-rigid beam-column connections. Response spectrum and modal analysis are carried out. Results of displacements, storey drift, storey shear, storey stiffness, base shear, time periods and first mode shapes of models are discussed. It is observed, precast reinforced concrete building models with semi rigid connection performs better than building models with pinned connections and building models with fixed supports reduces the structural response to a great extent.


2017 ◽  
Vol 259 ◽  
pp. 173-177
Author(s):  
Arthur L. Rocha ◽  
Marcelo de A. Ferreira ◽  
Wilian dos S. Morais ◽  
Bruna Catoia

Precast structures for multi-storey buildings can be designed with economy, safety and high performance. However, depending on the height of the building and the intensity of the lateral loads, the lateral stability system must be carefully chosen in order to maximize the global structural performance. In Brazil, the most common method for lateral stability is achieved by moment resisting precast-frames, wherein the moment-rotation response of the beam-column connections are responsible to provide the frame action, which will govern the distribution of internal forces and the sway distribution along the building height. On the other hand, in Europe, bracing systems comprised by shear walls or infill walls are mostly used, wherein beam-column connections are designed as hinged. The aim of this paper is to present a comparison between these methods for lateral stability, applying nine structural simulations with moment resisting precast-frames, shear walls and infill walls solutions, divided in three groups - 3 building with 5 storeys (21 meters high), 3 buildings with 10 storeys (41 meters high) and 3 building with 20 storeys (81 meters high). All first storeys are 5 meters high, while all the others are 4 meters high. The results from all structural analyses are compared. As conclusion, while moment-resisting beam-column connections are more feasible for applying in low-rise precast buildings, the use of shear walls and infill walls are more efficient for tall buildings due to decrease of lateral displacements, having a reduction of second order effects but also increasing the reactions at the foundations of bracing elements.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Luis Segura-Castillo ◽  
Nicolás García ◽  
Iliana Rodríguez Viacava ◽  
Gemma Rodríguez de Sensale

Fibre-reinforced concrete (FRC) has been used in numerous types of precast elements around the world, as has been shown that reductions in production costs and time can be obtained; however, there is little experience of this material in Uruguay. Therefore, our study analysed the feasibility of its utilisation in this country. This paper reports on the development of a simple analysis model that is useful for the design of FRC precast elements. The model efficiency was evaluated through its application to a practical case study—vertical precast concrete sandwich panel systems tested by bending. Three different types of reinforcement were analysed: synthetic fibres, metal fibres, and steel mesh. With the developed model, the cost-efficiency of different panel geometries and amounts of reinforcement were evaluated. The model allowed consideration of the contribution of the fibres to withstand internal tensile forces of the panels and therefore be able to substitute for the steel mesh in the panel wythes. It was found that it was possible to optimise panel reinforcement and geometry, thereby reducing wythe thickness. Besides the reduction in production time, it was possible to achieve cost savings of up to 10% by replacing steel mesh with fibres and of more than 20% if the geometry was also modified.


2013 ◽  
Vol 3 (2) ◽  
pp. 140-148
Author(s):  
M. Positieri ◽  
C. Baronetto ◽  
B. Raggiotti

RESUMENLas modernas instalaciones destinadas a la crianza intensiva de ganado porcino se construyen con elementos premoldeados de hormigón ensamblados in situ en grandes superficies techadas; están sujetas a un ambiente agresivo por los excrementos y vapores que el ganado porcino produce, produciéndose un recambio prematuro de piezas por la escasa durabilidad de las mismas. El trabajo presenta los resultados del estudio realizado sobre elementos premoldeados de hormigón (sin uso) que conforman la estructura, con el objetivo de verificar su comportamiento en las condiciones de servicio y realizar recomendaciones para asegurar su correcto desempeño. Se extrajeron testigos de las piezas y se midieron la resistencia a compresión, velocidad de pasaje de onda ultrasónica, absorción capilar, absorción y permeabilidad al aire. Los resultados obtenidos permiten calificar al hormigón entre regular y bueno y se presentan las recomendaciones que deberían considerarse al fabricar los elementos premoldeados para asegurar su durabilidad.Palabras Clave: hormigón; premoldeados; durabilidad; calidad; testigos.ABSTRACTThe modern installations for the intensive rearing of pigs are constructed based on precast concrete elements that are assembled on site in large areas covered and which are subject to an aggressive environment and in the feces they produce vapors, causing a premature replacement of parts by the low durability of the same. The paper presents the results of a study on precast concrete (unworn) that make up the structure in order to verify its performance in service conditions and make recommendations to assure its correct performance. Witnesses were extracted from the parts and measured the resistance to compression, speed of passage of the ultrasonic wave, capillary absorption, absorption and permeability to air. The results obtained allow us to qualify to the concrete between regular and good and presents the recommendations should be considered when manufacturing the precast elements to ensure their durability.Keywords: concrete; precast; durability; quality; witnesses.


2021 ◽  
Author(s):  
Marco Bovo ◽  
Lucia Praticò ◽  
Marco Savoia

Abstract The existing precast reinforced concrete structures, especially those not specifically designed against the earthquakes, have proved to be inadequate to withstand the remarkable seismic demands related to the presence of heavy roof elements. In fact, the cantilever columns entailing large top displacements and the poor devices adopted to connect different precast elements have shown high sensitivity to seismic actions. After the lesson learned from the recent Emilia earthquake of May 2012, causing many collapses and severe damage, reliable seismic design criteria have been established for the design of new precast structures and for the strengthening of the existing ones. Despite this, a large percentage of the existing precast buildings in the Italian territories actually has not been object of interventions and remains in an unsafe condition with regards to the seismic actions. In this context, the methods for a rapid seismic assessment can be very helpful both to estimate the current safety level of large building stocks and to plan the necessary strengthening interventions, possibly at the wide scale of an industrial area. To this aim, the paper proposes a new method, named PRESSAFE-disp (PRecast Existing Structure Seismic Assessment by Fast Evaluation-displacements), for the fast evaluation of the fragility curves of precast structures. The method follows the approach of the PRESSAFE method, but different damage criteria have been introduced in order to take into account the relative displacements and the sliding between different precast elements. The damage criteria considered, applicable to both structural elements and perimeter cladding elements conceived as non-structural elements, have been properly selected in order to capture the damage mechanisms observed during the several building inspections conducted by the authors in the aftermath of the 2012 Emilia earthquakes. In the present configuration, the method allows a comprehensive explanation of the seismic behaviour of the existing precast buildings and could be effectively adopted, for example, in earthquake loss estimations and seismic risk assessments of large Italian industrial areas, as well as of wide seismic-prone territories of the Mediterranean area.


2012 ◽  
Vol 166-169 ◽  
pp. 329-332
Author(s):  
Hai Xia Chen

In this paper ,taking industrial factory building , the size of 33 * 19.8 m2 for example, analyzes Integral reinforced concrete floor system under the loads by Finite element analysis software ANSYS. In the calculation process, beam element is beam4, slab element is shell63, Changing the line stiffness ratio of beam and slab, main beam and secondary beam, researches of moment on the main beam and the secondary beam by means of line stiffness ratio. It is showed that , when the value of line stiffness ratio is more than 10, mid-span moment is fewer obviously with the Increasing K ; when the value of line stiffness ratio is between 2 and 5, mid-span moment is fewer, too; when the value of line stiffness ratio is shorter than 2, mid-span moment does almost not changed.


1983 ◽  
Vol 109 (4) ◽  
pp. 843-858 ◽  
Author(s):  
J. Dario Aristizabal‐Ochoa

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