Download or read book A Study Into the Behavior of Reinforced Concrete Columns Under Fire Exposures Using a Spreadsheet Based Numerical Model written by Richard Lawrence Emberley and published by . This book was released on 2013 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Fire is a significant threat to the structural integrity of buildings. Depending on the architecture of the structure and the intensity and duration of the fire event, structural members may lose strength and stiffness eventually leading to collapse whether by flexural buckling or crushing. The focus of this research is on the behavior and fire performance of reinforced-concrete columns under fire conditions. In order to effectively study column performance with differing loading, aggregate and dimensional characteristics under varying time-temperature curves and fire exposures, a numerical model was constructed in Microsoft Excel. The spreadsheet model allowed for complete transparency of the calculations and provided a means to visualize the data in flexible ways. ANSYS and several published column furnace tests were used to benchmark the heat transfer and structural analysis portions of the model. One, three and four-sided fire exposures along with the ASTM E119 fire curve and a natural fire curve were used to study latent heating effects, increasing and decreasing eccentricities, moment magnification, and failure modes. Assessments of column structural capacity were performed in accordance with the provisions of ACI 318. The completed model served as an effective tool for the thesis and is available to help aid students and engineers investigate the design of reinforced concrete columns under fire conditions through integration the heat transfer analyses and the structural evaluations.

Download or read book Proceedings of SECON 2020 written by Kaustubh Dasgupta and published by Springer Nature. This book was released on 2020-11-20 with total page 959 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers peer-reviewed contributions presented at the 1st International Conference on Structural Engineering and Construction Management (SECON’20), held in Angamaly, Kerala, India, on 14-15 May 2020. The meeting served as a fertile platform for discussion, sharing sound knowledge and introducing novel ideas on issues related to sustainable construction and design for the future. The respective contributions address various aspects of numerical modeling and simulation in structural engineering, structural dynamics and earthquake engineering, advanced analysis and design of foundations, BIM, building energy management, and technical project management. Accordingly, the book offers a valuable, up-to-date tool and essential overview of the subject for scientists and practitioners alike, and will inspire further investigations and research.

Download or read book Residual Axial Capacity of Fire Exposed Reinforced Concrete Columns written by Derek R. Hibner and published by . This book was released on 2017 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fire Behaviour of Self consolidating Concrete filled Double Skin Steel Tubular Columns written by Hui Lu and published by . This book was released on 2010 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concrete-filled double skin tubular column (CFDST) is an innovative type of steel-concrete element which has potential for use as piers in bridges and columns in buildings. The use of self-compacting concrete (SCC) in CFDST is seen as a solution to resolve the challenge of concrete compaction in the columns. The behaviour of CFDST under static and cyclic loading at ambient temperature has been extensively studied. The fire performance of CFDST is crucial due to the direct fire exposure of the outer steel tube. Nevertheless, there is at present little information about the fire performance of CFDST. This thesis reports on research into the fire performance of SCC-filled CFDST columns. The research aims to understand the fundamental behaviour of SCC-filled CFDST columns under standard fire exposure by means of standard fire tests and finite element modelling and to develop guidance for fire resistance design of the columns.Given the complexity in the responses of SCC-filled CFDST in fires, SCC-filled steel tubular stub columns (CFST), a specific type of CFDST without an inner steel tube, were selected for study in the first phase of the research program because of their simple configuration. Six SCC-filled CFST stub columns were prepared for standard fire tests and a finite element model to simulate the thermal and structural responses was developed. The main purpose of this phase of research was to develop a methodology for the further study of fire behaviour of CDFST columns by investigating how SCC affects the fire behaviour of composite columns and how steel tube affords confinement of the SCC to alter its behaviour at elevated temperature.A series of standard fire tests for CFDST columns was conducted in the second phase of the research. Six CFDST columns and sixteen CFDST stub columns were prepared for standard fire tests. A further two CFDST stub columns were prepared as reference specimens to test the axial capacity at ambient temperature. The columns and stub columns in the tests represent slender and stub columns in authentic engineering practice in which the failure modes are buckling and compression failure respectively. Data obtained from the fire tests, i.e. temperatures, axial deformation, failure modes and fire resistance, were used to investigate the fire behaviour of the columns. Interaction among the three components in the columns during fire exposure was clearly shown in the tests. Such interaction is beneficial to the fire performance of CFDST columns. Confinement of the tubes on the SCC prevents its spalling. Components which help each other through a load transfer mechanism are typical of the composite interaction in CFDST columns. Methods to enhance the fire resistance performance of CFDST, i.e. fire protection and steel fibre reinforced concrete, were also validated in the tests. In addition, the fire tests accumulated data to verify the numerical model in the subsequent research.A finite element model was developed and used to study in detail the fire behaviour of CFDST columns and for the parametric study in the third phase of the research. An advanced finite element model which accounts for material and geometric non-linearity and the interaction of tubes and concrete was proposed to simulate the thermal and structural responses of CFDST columns under standard fire exposure. A concrete material model for confined concrete in CFDST at elevated temperature was developed accordingly. The model was then used to analyse the fire behaviour of the columns in terms of stress, strain and load share in components which cannot be obtained directly from fire tests. Yield of the inner steel tube was found to be a major cause of the final failure of the columns. The influence of a number of parameters on the fire resistance performance of the columns was investigated. The parameters which have significant influence on the fire resistance performance of the columns were identified. Finally, guidelines for the fire resistance design of CFDST columns are proposed. These guidelines deal with how to appropriately select parameters for CFDST columns to ensure the columns achieve the anticipated fire resistance. Several practical design tables are also presented to illustrate how to use the guidelines to design CFDST columns to achieve a certain level of fire resistance.

Download or read book Fire Resistance of Concrete filled and Reinforced Concrete Columns microform written by El-Shayeb, Mohamed and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 1986 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to calculate the fire resistance of a building component, it is necessary to know the temperature history of the component during exposure to fire. In this dissertation a numerical method is described for calculating the temperature field in fire-exposed columns. The procedure is based on a finite difference method for calculating the temperature history of concrete-filled square steel and cylindrical reinforced concrete columns. Two mathematical models and their related computer programs for these columns are presented in this dissertation. Furthermore, the Division of Building Research of the National Research Council of Canada, is now carrying out extensive experimental studies on building columns. These studies include the testing of various columns under fire conditions. The data obtained from these tests will be used to determine the validity of the new models. In order to perform these tests the maximum allowable load must be known. Two mathematical models and their related computer programs to calculate the maximum allowable load of various column cross-sections are also presented in this dissertation.

Download or read book Fire Design of Concrete Structures Structural Behaviour and Assessment written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2008-01-01 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete is well known to behave efficiently in fire conditions, as it is incombustible, does not emit smoke, and provides good thermal insulation. Furthermore, in reinforced concrete structures, the concrete cover gives a natural protection to the reinforcement, and the size of the sections often delays the heating of the core, thus favouring the fire resistance of the structural members. In addition, concrete structures are often robust and therefore able to accommodate local damage without major consequences to the overall structural integrity. However, past experience with real fires shows that a thorough understanding of concrete behaviour and structural mechanics is still needed to improve the design of R/C structures with respect to fire. The objective of fib Bulletin 46 is to augment the current knowledge about concrete and concrete structures under fire, not only for the design of new structures, but also for the analysis and repair of existing fire-damaged structures. Both structural and materials issues are examined, and the results of the most recent research activities on the structural performance of concrete subjected to fire are reported. Special attention is paid to the indirect actions caused by the restrained thermal deformations and several basic examples show how a local fire influences global structural behaviour. fib Bulletin 46 is intended for use by practicing engineers to improve their understanding of the behaviour of concrete structures in fire and thereby produce better and safer design standards.

Download or read book Modeling the Behavior of Lightly Reinforced Concrete Columns Subjected to Lateral Loads written by Eric John Setzler and published by . This book was released on 2005 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Prior studies have shown that many reinforced concrete buildings located in seismically active regions do not have the necessary lateral strength and ductility to perform adequately in earthquakes. In particular, it has been noted that reinforced concrete columns with poor transverse reinforcement are susceptible to shear failure and loss of axial capacity under cyclic lateral loads. The research reported here is focused on modeling the lateral deformation behavior of lightly reinforced concrete columns subjected to lateral loads. Lateral deformations in a column are comprised of three parts: flexural, reinforcement slip, and shear deformations. The monotonic response for each of these deformations was modeled separately. Flexural deformations were modeled using moment-curvature analysis and a plastic hinge model. A review of existing models for reinforcement slip was completed, and an existing model was modified based on experimental data and a parametric study. A comparison of models showed that the proposed slip model performs well in terms of accuracy and efficiency. A shear model was adopted from a previous study, and combined with an available computer program to predict shear behavior in this study. These three component models were found to predict the lateral response envelopes acceptably well for several sets of experimental data. A model for the overall lateral force-deformation relationship of reinforced concrete columns was created by combining the effects of each of the component models. The behavior of a column is classified into one of five categories based on a comparison of the shear, yield, and flexural strengths. The expected behavior in each category determines rules that govern the combination of the deformation components. For columns that are susceptible to shear failure after the onset of flexural failure, the response envelope is modified based on an available shear capacity model. An axial capacity model is also employed for the prediction of ultimate deformations. The proposed model was compared with experimental data from 37 column tests by various researchers. It was found that the classification system employed in the model was successful in representing column behavior. Overall, the model did a reasonable job of predicting the lateral response envelope for the columns in the test database. The model predicted the peak lateral strength well, and successfully represented the onset of shear failure in columns initially failing in flexure.

Download or read book Transforming Construction Advances in Fiber Reinforced Concrete written by Viktor Mechtcherine and published by Springer Nature. This book was released on with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reliability of Steel Columns Protected by Intumescent Coatings Subjected to Natural Fires written by Chao Zhang and published by Springer. This book was released on 2015-02-25 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studied the effect of aging of intumescent coatings (ICs) on the reliability of protected steel columns in fire condition and developed a probabilistic approach to assess the service life of ICs applied on steel columns. In the study, Monte Carlo simulations were conducted to obtain the reliability index or failure probability of steel columns protected by ICs subjected to compartment fires. The effect of aging of intumescent coatings on the failure probability of protected steel columns was investigated by using variable insulation property of intumescent coatings in the simulation. The test data on aging effect on insulation property of intumescent coatings from literature was used. Based on the reliability analysis, a probabilistic approach is given to determine the service life of intumescent coatings for steel columns. In that approach, the failure probability of the protected steel columns is compared with the target probability of the structural fire design. The approach can also be used for probabilistic analysis of steel columns protected by conventional inert fire protection materials.

Download or read book Transactions of the American Society of Civil Engineers written by American Society of Civil Engineers and published by . This book was released on 2003 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. 29-30 contain papers of the International Engineering Congress, Chicago, 1893; v. 54, pts. A-F, papers of the International Engineering Congress, St. Louis, 1904.

Download or read book Fire Effects on Reinforced Concrete Members written by Bruce R. Ellingwood and published by . This book was released on 1979 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Determination of the Residual Compressive Strength of Concrete Columns Subjected to Different Fire Durations and Load Ratios written by Anjaly Nair and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The superior thermal property of concrete associated to its great capability of thermally insulating the embedded reinforcing steel rebar is the main reason for the good behavior of reinforced concrete structural elements in fire condition, compared to other construction materials. However, at elevated temperatures, concrete still undergoes changes in its mechanical and thermal properties, which mainly cause degradation of strength and may lead to the failure of the structure. Retrofitting is a desirable alternative to rehabilitate post-fire concrete structures. However, in order to ensure safe reuse of fire-exposed buildings and to adopt proper retrofitting methods, it is essential to evaluate the residual strength capacity of fire-damaged reinforced concrete structural elements. The focus of this experimental research study is to investigate the fire performance of reinforced concrete columns exposed to elevated temperatures that followed CAN/ULC-S101 standard fire, and then evaluate their residual compressive strengths after fire exposure. In order to effectively study the fire performance of such columns, eight identical 200 x 200 x 1500mm high reinforced-concrete column test specimens were subjected to two different durations of standard fire exposure (1 hour and 2 hours) while being loaded with two different axial load ratios (20% and 40% of the column ultimate design axial compressive load capacity). In a subsequent stage and after complete cooling down, residual compressive strength capacity tests were performed on the fire-exposed columns. Experimental results showed that the residual compressive strength capacity dropped to almost 50% and 30% of its ambient temperature capacity for the columns exposed to 1- and 2-hour fire durations, respectively. It was also noticed that the applied load ratio has less effect on the column's residual compressive strength compared to that of the fire duration.

Download or read book Robustness of Connections to Concrete filled Steel Tubular Columns Under Fire During Heating and Cooling written by Sherif Ahmed Elkarim Ibrahim Soliman Elsawaf and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Joint behaviour in fire is currently one of the most important topics of research in structural fire resistance. The collapse of World Trade Center buildings and the results of the Cardington full-scale eight storey steel framed building fire tests in the UK have demonstrated that steel joints are particularly vulnerable during the heating and cooling phases of fire. The main purpose of this research is to develop robust joints to CFT columns that are capable of providing very high rotational and tying resistances to make it possible for the connected beam to fully develop catenary action during the heating phase of fire attack and to retain integrity during the cooling phase of fire attack. This research employed the general finite element software ABAQUS to numerically model the behaviour of restrained structural subassemblies of steel beam to concrete filled tubular (CFT) columns and their joints in fire. For validation, this research compared the simulation and test results for 10 fire tests previously conducted at the University of Manchester. It was envisaged that catenary action in the connected beams at very large deflections would play an important role in ensuring robustness of steel framed structures in fire. Therefore, it was vital that the numerical simulations could accurately predict the structural behaviour at very large deflections. In particular, the transitional behaviour of the beam from compression to catenary action presented tremendous difficulties in numerical simulations due to the extremely high rate of deflection increase. This thesis will explain the methodology of a suitable simulation method, by introducing a pseudo damping factor. The comparison between the FE and the experimental results demonstrates that the 3-D finite element model is able to successfully simulate the fire tests. The validated ABAQUS model was then applied to conduct a thorough set of numerical studies to investigate methods of improving the survival temperatures under heating in fire of steel beams to concrete filled tubular (CFT) columns using reverse channel connection. This study investigated five different joint types of reverse channel connection: extended endplate, flush endplate, flexible endplate, hybrid flush/flexible endplate and hybrid extended/flexible endplate. The connection details investigated include reverse channel web thickness, bolt diameter and grade, using fire-resistant (FR) steel for different joint components (reverse channel, end plate and bolts) and joint temperature control. The effects of changing the applied beam and column loads were also considered. It is concluded that by adopting some of the joint details to improve the joint tensile strength and deformation capacity, it is possible for the beams to develop substantial catenary action to survive very high temperatures. This thesis also explains the implications on fire resistant design of the connected columns in order to resist the additional catenary force in the beam. The validated numerical model was also used to perform extensive parametric studies on steel framed structures using concrete filled tubular (CFT) columns with flexible reverse channel connection and fin plate connection to find means of reducing the risk of structural failure during cooling. The results lead to the suggestion that in order to avoid connection fracture during cooling, the most effective and simplest method would be to reduce the limiting temperature of the connected beam by less than 50°C from the limiting temperature calculated without considering any axial force in the beam.

Download or read book The Behavior of Concrete Structures in Fire written by Scientific and Technical Center for Architectural Engineering and published by . This book was released on 1978 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: This method provides a means for predicting, by calculation, the resistance to fire of a reinforced or prestressed concrete element of construction, in accordance with 1959 French directives. The method is useful in allowing builders to design structures which show the degree of fire resistance required by the various French construction regulations in force. According to those regulations, only a test furnishes legal proof of fire resistance. French researchers hope this first step will lead to the acceptance in France of fire resistance calculations as legal proof of satisfactory resistance.

Download or read book Parametric Study of the Behaviour of Reinforced Concrete Columns in Fire written by Kamal Nasharuddin Mustapha and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fire Tests of Building Columns written by Associated Factory Mutual Fire Insurance Companies and published by . This book was released on 1919 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of Reinforced Concrete Columns Under Shock Tube Induced Shock Wave Loading written by Alan Lloyd and published by . This book was released on 2010 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: