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1 – 10 of 52Takashi Hara, Shiro Kato and Hiroshi Nakamura
Reinforced concrete (R/C) hyperbolic cooling towers are the largest thin‐shell structures ever constructed. These towers stand more than 150m tall and have wall thicknesses of…
Abstract
Reinforced concrete (R/C) hyperbolic cooling towers are the largest thin‐shell structures ever constructed. These towers stand more than 150m tall and have wall thicknesses of 0.20‐0.25m. Therefore, these can be classified as thin‐shell structures. Analyses the influences of both the reinforcing ratio and the tensile strength of the concrete on the strength of the R/C cooling tower shells. In the numerical analysis Port Gibson tower is adopted for the numerical model and the finite element method is applied to examine the non‐linear behaviour of the cooling tower shells. From the load displacement curves the initial crack strength and the ultimate strength are determined. Also presents the stress redistribution processes and demonstrates the influences of these problems on the strength of the cooling tower shells.
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Smitha Gopinath, Nagesh Iyer, J. Rajasankar and Sandra D'Souza
The purpose of this paper is to present integrated methodologies based on multilevel modelling concepts for finite element analysis (FEA) of reinforced concrete (RC) shell…
Abstract
Purpose
The purpose of this paper is to present integrated methodologies based on multilevel modelling concepts for finite element analysis (FEA) of reinforced concrete (RC) shell structures, with specific reference to account for the nonlinear behaviour of cracked concrete and the other associated features.
Design/methodology/approach
Geometric representation of the shell is enabled through multiple concrete layers. Composite characteristic of concrete is accounted by assigning different material properties to the layers. Steel reinforcement is smeared into selected concrete layers according to its position in the RC shell. The integrated model concurrently accounts for nonlinear effects due to tensile cracking, bond slip and nonlinear stress‐strain relation of concrete in compression. Smeared crack model having crack rotation capability is used to include the influence of tensile cracking of concrete. Propagation and change in direction of crack along thickness of shell with increase in load and deformation are traced using the layered geometry model. Relative movement between reinforcing steel and adjacent concrete is modelled using a compatible bond‐slip model validated earlier by the authors. Nonlinear iterative solution technique with imposed displacement in incremental form is adopted so that structures with local instabilities or strain softening can also be analysed.
Findings
Proposed methodologies are validated by evaluating ultimate strength of two RC shell structures. Nonlinear response of McNeice slab is found to compare well with that of experiment available in literature. Then, a RC cooling tower is analysed for factored wind loads to study its behaviour near ultimate load. Numerical validation demonstrates efficacy and usefullness of the proposed methodologies for nonlinear FEA of RC shell structures.
Originality/value
The present paper integrates critical methodologies used for behaviour modelling of concrete and reinforcement with the physical interaction among them. The study is unique by considering interaction of tensile cracking and bond‐slip which are the main contributors to nonlinearity in the nonlinear response of RC shell structures. Further, industrial application of the proposed modelling strategy is demonstrated by analysing a RC cooling tower shell for its nonlinear response. It is observed that the proposed methodologies in the integrated manner are unique and provide stability in nonlinear analysis of RC shell structures.
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Mahesh Gaikwad, Suvir Singh, N. Gopalakrishnan, Pradeep Bhargava and Ajay Chourasia
This study investigates the impact of the fire decay phase on structural damage using the sectional analysis method. The primary objective of this work is to forecast the…
Abstract
Purpose
This study investigates the impact of the fire decay phase on structural damage using the sectional analysis method. The primary objective of this work is to forecast the non-dimensional capacity parameters for the axial and flexural load-carrying capacity of reinforced concrete (RC) sections for heating and the subsequent post-heating phase (decay phase) of the fire.
Design/methodology/approach
The sectional analysis method is used to determine the moment and axial capacities. The findings of sectional analysis and heat transfer for the heating stage are initially validated, and the analysis subsequently proceeds to determine the load capacity during the fire’s heating and decay phases by appropriately incorporating non-dimensional sectional and material parameters. The numerical analysis includes four fire curves with different cooling rates and steel percentages.
Findings
The study’s findings indicate that the rate at which the cooling process occurs after undergoing heating substantially impacts the axial and flexural capacity. The maximum degradation in axial and flexural capacity occurred in the range of 15–20% for cooling rates of 3 °C/min and 5 °C/min as compared to the capacity obtained at 120 min of heating for all steel percentages. As the fire cooling rate reduced to 1 °C/min, the highest deterioration in axial and flexural capacity reached 48–50% and 42–46%, respectively, in the post-heating stage.
Research limitations/implications
The established non-dimensional parameters for axial and flexural capacity are limited to the analysed section in the study owing to the thermal profile, however, this can be modified depending on the section geometry and fire scenario.
Practical implications
The study primarily focusses on the degradation of axial and flexural capacity at various time intervals during the entire fire exposure, including heating and cooling. The findings obtained showed that following the completion of the fire’s heating phase, the structural capacity continued to decrease over the subsequent post-heating period. It is recommended that structural members' fire resistance designs encompass both the heating and cooling phases of a fire. Since the capacity degradation varies with fire duration, the conventional method is inadequate to design the load capacity for appropriate fire safety. Therefore, it is essential to adopt a performance-based approach while designing structural elements' capacity for the desired fire resistance rating. The proposed technique of using non-dimensional parameters will effectively support predicting the load capacity for required fire resistance.
Originality/value
The fire-resistant requirements for reinforced concrete structures are generally established based on standard fire exposure conditions, which account for the fire growth phase. However, it is important to note that concrete structures can experience internal damage over time during the decay phase of fires, which can be quantitatively determined using the proposed non-dimensional parameter approach.
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Nicolas Berland and Marie‐Claire Loison
The purpose of this study is to focus on the policy of corporate social responsibility (CSR) launched in the chemical industry in the 1980s and known as “Responsible Care” (RC)…
Abstract
Purpose
The purpose of this study is to focus on the policy of corporate social responsibility (CSR) launched in the chemical industry in the 1980s and known as “Responsible Care” (RC). The debate surrounding this issue prompts us to question the ever‐changing nature of this policy and the way to measure the performance achieved.
Design/methodology/approach
The findings are drawn from analysis of a double set of data including a longitudinal survey and a current case study. Blending these two data sets allows a better understanding of the ongoing building process of “RC” and, more broadly, of CSR.
Findings
This paper asserts that, contrary to the common wisdom developed in research, companies do not simply react to stakeholder pressure. Companies autonomously develop ways to protect their environment and so contribute to changing society's expectations. Thus, performance cannot be read without a dynamic perspective in mind.
Research limitations/implications
The authors' findings lead them to reconsider the assessment of companies' sustainable performances by taking into account the fabricating process of sustainable activities. The main limitation of this research stems from the single unit of analysis considered. Broader studies will be necessary to enrich our understanding of corporate policies.
Originality/value
The paper stands apart from the traditional view of organizations as cynical actors and attempts to provide a more complex picture of the behaviours observed.
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Benjamin Valdez, Michael Schorr, Margarito Quintero, Monica Carrillo, Roumen Zlatev, Margarita Stoytcheva and Juan de Dios Ocampo
The aim of this work is to study the corrosion and scaling factors, mechanisms and processes affecting the materials, equipment and installations of the Cerro Prieto geothermal…
Abstract
Purpose
The aim of this work is to study the corrosion and scaling factors, mechanisms and processes affecting the materials, equipment and installations of the Cerro Prieto geothermal field (GTF).
Design/methodology/approach
The physicochemical characteristics of the geothermal well and fluids were analysed, recorded and related to the corrosion and scaling phenomena.
Findings
The high temperature and salinity of the steam‐brine mixture and the presence of hydrogen sulphide and carbon dioxide impart a severe level of corrosivity.
Originality/value
Corrosion and scaling control assure an efficient production regime, provide for the durability of the GTF engineering materials and equipment and contribute to environmental quality.
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This paper conducted a study on the energy-saving potential of a developed thermotropic window. Office buildings in different climate regions of China were compared in terms of…
Abstract
This paper conducted a study on the energy-saving potential of a developed thermotropic window. Office buildings in different climate regions of China were compared in terms of heating, cooling and lighting energy demands. Results show that annual heating and cooling energy demands for office buildings differ largely, while lighting energy demand at different climates keeps a significant percentage of the total energy demand, ranging from 36.1% to 66.3%. Meanwhile, thermotropic windows achieve a great advantage in improving daylighting performance and in reducing the overall energy demand, by reducing the overall energy demand by 2.27%-8.7% and 10.1%-21.72%, respectively, compared to movable shading devices and Low-E windows. This means that this kind of thermotropic windows have a great potential in applications in different climatic regions and can be considered as a good substitute of solar shading devices and Low-E windows.
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Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…
Abstract
Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.
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Ecological architecture consciousness has started spreading out with the idea that the limited resources that remain on the world in 21st century due to the damage caused by…
Abstract
Ecological architecture consciousness has started spreading out with the idea that the limited resources that remain on the world in 21st century due to the damage caused by humans should be used economically. Energy saving consciousness should be executed in all stages from the design of the building to its construction and use. The number of buildings in the world that have been built with this consciousness continues to increase. Many technological applications have been put forth in order to ensure that a building supplies its own energy. This new situation contributes to the decreasing of the energy need of the building while also making significant savings in the Gross National Income of developing countries such as Turkey which are dependent to other countries for energy. When the contribution of ecologic designs to the country economy is considered, it is expected that the government and local administrations increase incentives especially for government buildings thereby leading the way. The objective of this study is to examine the energy consumption of Kadir Has City Stadium built in the city of Kayseri and to question the contribution of the local administration in terms of ecologic approach. It is expected that the study will make a contribution so that the local administrations will support all the stages of government buildings from the design to construction.
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Shows how a single creative idea provided the platform for communications which were not only genuinely integrated but permeated the business of theme park Alton Towers: this was…
Abstract
Shows how a single creative idea provided the platform for communications which were not only genuinely integrated but permeated the business of theme park Alton Towers: this was the launch of the Air ride, and the advertising for it, which enhanced positive attitudes towards the brand, and led to increased visitorship and secondary spend, plus additional revenue from sponsorship. Explores the careful reinvention of its brand image that Alton Towers, which is the UK’s leading theme park, has undertaken since 1991: this repositioning is away from its original youth brand image to a being family resort destination. Describes the revolutionary nature of the Air rollercoaster ride and details the 2002 advertising campaign for its launch. Includes tables to illustrate the progress made in prompted awareness and related advertising data for the campaign.
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