Results and analysis of a large-scale fire test on a multi-bay composite steel-frame floor system

2016 ◽  
Vol 7 (1) ◽  
pp. 19-29 ◽  
Author(s):  
David J. Proe

Purpose This paper aims to facilitate verification of computer modelling techniques for complex structures exposed to fire and to test the effect of some steel beams being left unprotected. Design/methodology/approach This paper describes a fire test conducted on a large-scale structure representing four corner bays of a typical multi-storey steel-frame office building. Findings A new and unexpected mode of damage occurred. Originality/value The test results indicate that an alternate reinforcement detail should be used in combination with unprotected beams.

2014 ◽  
Vol 79 (704) ◽  
pp. 1559-1568
Author(s):  
Takeo HIRASHIMA ◽  
Kazuma OKUWAKI ◽  
Xuansu ZHAO ◽  
Yuki SAGAMI ◽  
Koji TOYODA

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4336
Author(s):  
Jiří Teslík

Sustainable development in civil engineering is the clear and necessary goal of the current generation. There are many possibilities for reducing the use of depletable resources. One of them is to use renewable and recyclable materials on a larger scale in the construction industry. One possibility is the application of natural thermal insulators. A typical example is a crushed straw, which is generated as agricultural waste in the Czech Republic. Due to its small dimensions and good thermal insulation parameters, this material can also be used as blown thermal insulation. The research aims to examine the fire resistance of crushed straw as blown insulation. The single-flame source fire test results, thermal attack by a single burning item (SBI) test and large-scale test of a perimeter wall segment are shown. The results show that blown insulation made of crushed straw meets the requirements of fire protection. In addition, crushed straw can be also used to protect load-bearing structures due to its behaviour. This article also shows the production process of crushed straw used as blown insulation in brief.


2020 ◽  
Vol 47 (3) ◽  
pp. 547-560 ◽  
Author(s):  
Darush Yazdanfar ◽  
Peter Öhman

PurposeThe purpose of this study is to empirically investigate determinants of financial distress among small and medium-sized enterprises (SMEs) during the global financial crisis and post-crisis periods.Design/methodology/approachSeveral statistical methods, including multiple binary logistic regression, were used to analyse a longitudinal cross-sectional panel data set of 3,865 Swedish SMEs operating in five industries over the 2008–2015 period.FindingsThe results suggest that financial distress is influenced by macroeconomic conditions (i.e. the global financial crisis) and, in particular, by various firm-specific characteristics (i.e. performance, financial leverage and financial distress in previous year). However, firm size and industry affiliation have no significant relationship with financial distress.Research limitationsDue to data availability, this study is limited to a sample of Swedish SMEs in five industries covering eight years. Further research could examine the generalizability of these findings by investigating other firms operating in other industries and other countries.Originality/valueThis study is the first to examine determinants of financial distress among SMEs operating in Sweden using data from a large-scale longitudinal cross-sectional database.


2020 ◽  
pp. 136943322098166
Author(s):  
Shuhao Yin ◽  
Bin Rong ◽  
Lei Wang ◽  
Yiliang Sun ◽  
Wuchen Zhang ◽  
...  

This paper studies the shear performance of the connection with the external stiffening ring between the square steel tubular column and unequal-depth steel beams. Two specimens of interior column connections were tested under low cyclic loading. The deformation characteristics and failure modes exhibited by the test phenomena can be summarized as: (1) two specimens all exhibited shear deformation in steel tube web of the panel zone and (2) weld fracture in the panel zone and plastic hinge failure at beam end were observed. Besides, load-displacement behaviors and strain distributions have been also discussed. The nonlinear finite element models were developed to verify the test results. Comparative analyses of the bearing capacity, failure mode, and load-paths between the equal-depth and unequal-depth beam models have been carried out.


2016 ◽  
Vol 28 (4) ◽  
pp. 245-262 ◽  
Author(s):  
Annalisa Sannino ◽  
Yrjö Engeström ◽  
Johanna Lahikainen

Purpose The paper aims to examine organizational authoring understood as a longitudinal, material and dialectical process of transformation efforts. The following questions are asked: To which extent can a Change Laboratory intervention help practitioners author their own learning? Are the authored outcomes of a Change Laboratory intervention futile if a workplace subsequently undergoes large-scale organizational transformations? Does the expansive learning authored in a Change Laboratory intervention survive large-scale organizational transformations, and if so, why does it survive and how? Design/methodology/approach The paper develops a conceptual argument based on cultural–historical activity theory. The conceptual argument is grounded in the examination of a case of eight years of change efforts in a university library, including a Change Laboratory (CL) intervention. Follow-up interview data are used to discuss and illuminate our argument in relation to the three research questions. Findings The idea of knotworking constructed in the CL process became a “germ cell” that generates novel solutions in the library activity. A large-scale transformation from the local organization model developed in the CL process to the organization model of the entire university library was not experienced as a loss. The dialectical tension between the local and global models became a source of movement driven by the emerging expansive object. Practitioners are modeling their own collective future competences, expanding them both in socio-spatial scope and interactive depth. Originality/value The article offers an expanded view of authorship, calling attention to material changes and practical change actions. The dialectical tensions identified serve as heuristic guidelines for future studies and interventions.


2021 ◽  
Vol 111 ◽  
pp. 103844
Author(s):  
Jintao Duan ◽  
Yuli Dong ◽  
Jianzhuang Xiao ◽  
Dashan Zhang ◽  
Wei Zheng ◽  
...  

2021 ◽  
Vol 11 (7) ◽  
pp. 3266
Author(s):  
Insub Choi ◽  
Dongwon Kim ◽  
Junhee Kim

Under high gravity loads, steel double-beam floor systems need to be reinforced by beam-end concrete panels to reduce the material quantity since rotational constraints from the concrete panel can decrease the moment demand by inducing a negative moment at the ends of the beams. However, the optimal design process for the material quantity of steel beams requires a time-consuming iterative analysis for the entire floor system while especially keeping in consideration the rotational constraints in composite connections between the concrete panel and steel beams. This study aimed to develop an optimal design method with the LM (Length-Moment) index for the steel double-beam floor system to minimize material quantity without the iterative design process. The LM index is an indicator that can select a minimum cross-section of the steel beams in consideration of the flexural strength by lateral-torsional buckling. To verify the proposed design method, the material quantities between the proposed and code-based design methods were compared at various gravity loads. The proposed design method successfully optimized the material quantity of the steel double-beam floor systems without the iterative analysis by simply choosing the LM index of the steel beams that can minimize objective function while satisfying the safety-related constraint conditions. In particular, under the high gravity loads, the proposed design method was superb at providing a quantity-optimized design option. Thus, the proposed optimal design method can be an alternative for designing the steel double-beam floor system.


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