Pedro Palma, Andrea Frangi, Erich Hugi, Paulo Cachim and Helena Cruz
This paper aims to present the results of an extensive experimental programme on the fire behaviour of timber beam-to-column shear connections, loaded perpendicularly to the grain.
Abstract
Purpose
This paper aims to present the results of an extensive experimental programme on the fire behaviour of timber beam-to-column shear connections, loaded perpendicularly to the grain.
Design/methodology/approach
The experimental programme comprised tests at normal temperature and loaded fire resistance tests on beam-to-column connections in shear. Twenty-four full-scale tests at normal temperature were performed covering nine different connection typologies, and 19 loaded fire resistance tests were conducted including 11 connections typologies.
Findings
The results of the fire resistance tests show that the tested typologies of steel-to-timber dowelled connections reached more than 30 and even 60 minutes of fire resistance. However, aspects such as a wider gap between the beam and the column, reduced dowel spacing, and the presence of reinforcement with self-drilling screws all have a negative influence on the fire resistance.
Originality/value
The experimental programme addressed the fire behaviour of timber beam-to-column shear connections loaded perpendicularly to the grain in a systematic way testing a wide range of common connection typologies significantly enlarging their experimental background.
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Keywords
Joachim Schmid, Alessandro Santomaso, Daniel Brandon, Ulf Wickström and Andrea Frangi
The purpose of this study is to investigate the influencing factors on the charring behaviour of timber, the char layer and the charring depth in non-standard fires.
Abstract
Purpose
The purpose of this study is to investigate the influencing factors on the charring behaviour of timber, the char layer and the charring depth in non-standard fires.
Design/methodology/approach
This paper summarizes outcomes of tests, investigating the influences on the charring behavior of timber by varying the oxygen content and the gas velocity in the compartment. Results show that charring is depending on the fire compartment temperature, but results show further that at higher oxygen flow, char contraction was observed affecting the protective function of the char layer.
Findings
In particular, in the cooling phase, char contraction should be considered which may have a significant impact on performance-based design using non-standard temperature fire curves where the complete fire history including the cooling phase has to be taken into account.
Originality/value
Up to now, some research on non-standard fire exposed timber member has been performed, mainly based on standard fire resistance tests where boundary conditions as gas flow and oxygen content especially in the decay phase are not measured or documented. The approach presented in this paper is the first documented fire tests with timber documenting the data required.
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Keywords
This paper introduces and develops a conceptual model, “organizational job crafting,” to extend and apply job crafting theory to precarious workers.
Abstract
Purpose
This paper introduces and develops a conceptual model, “organizational job crafting,” to extend and apply job crafting theory to precarious workers.
Design/methodology/approach
This conceptual model incorporates the perspectives of organizational justice theory into job crafting theory to identify precarious workers’ unique job crafting motivation and processes in their work environment. The theory is developed by integrating and adjusting aspects of these two approaches.
Findings
This model invokes five propositions specifying (1) the impacts of organizational justice on individual motivations for job crafting, (2) the conditions for developing a shared perception of organizational justice, (3) the forms of organizational job crafting and (4) the individual and organizational effects of job crafting. Moderating conditions are identified, such as the level of connection to labor/community organizations.
Originality/value
This study extends established job crafting theory, enriching it by incorporating the precarious worker perspective. By connecting job crafting to organizational justice theories, this model opens the possibility that workers’ job crafting can produce not only personal enrichment or work efficiency but also contribute to organizational changes. The theoretical development handles issues blocked or hidden by the original constituent theoretical ingredients.