Theoretical and experimental analysis of load-carrying capacity of steel-concrete composite beams with glass-fibre-concrete slab
The paper deals with the problems of the theoretical and experimental investigation of load-carrying capacity of steel-concrete composite beams with glass-fibre-concrete (GFC) slab. The paper presents some selected results of the more extensive research realized on the authors workplace and oriented to the utilization of high-strength steels and high-performance concretes in steel-concrete composite structural members. This paper is directed towards one part of this research only, which represents theoretical analysis of the bending moment capacity and experimental verification of the actual bending moment capacity of steel-concrete composite beams with glass-fibre-concrete (GFC) slab in connection with their actual behaviour and corresponding relevant failure mechanism. Within the framework of the bending moment capacity analysis four basic types of beams have been (or will be, respectively) investigated, all of them composed of 3 different steel IPE cross-sections (IPE180, IPE200, IPE220) and concrete slab: (i) beams with GFC slab without usual steel reinforcement subjected to sagging bending moment, to investigate the contribution of GFC only to the sagging moment capacity; (ii) beams with GFC slab with steel reinforcement (reduced amount) subjected to sagging bending moment, to investigate the contribution of GFC slab and steel reinforcement together to the sagging moment capacity and to compare it with the first case; (iii) beams with plain concrete (PC) slab subjected to the sagging bending moment, to compare the results with the first case only; (iv) beams with GFC slab without steel reinforcement subjected to hogging bending moment, to verify the contribution of GFC to the hogging moment capacity. During the experimental parts of this research in common 27 loading tests of steel-concrete composite beams have been realized so far (but no all results are evaluated in detail so far) and other 9 specimens will be tested immediately. The attention was paid mainly to the following significant problems: the efficiency of the utilization of fibre-concrete slab in steel-concrete composite beams subjected to sagging or hogging bending moments, too; the effectiveness of the contribution of glass-fibre-concrete to the moment capacity of steel-concrete composite beams in comparison with reinforced concrete and plain concrete. Key-Words: Composite member, steel-concrete beam, glass-fibre-concrete, load-carrying capacity, resistance, sagging bending moment, experimental verification, theoretical analysis.
Stability problems of steel‐concrete members composed of high‐strength materials
Abstract The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utiliza...
Ethics and the Treatment of the Mentally Ill, Homeless Person: a Perspective on Psychiatry Resident Training
ObjectiveThe authors outline the unique ethical challenges that psychiatry residents face in working with individuals who are homeless and mentally ill. The authors also propose steps to develop effective teaching methods with residents working with these patients.MethodsThe authors reviewed literature relevant to the training of psychiatry residents in ethics and treating individuals who are homeless and mentally ill.ResultsThe authors summarize current literature and, with the use of case examples, provide guidelines for effective teaching.ConclusionsTeaching psychiatry residents who are working in the community with individuals who are mentally ill and homeless needs to address a number of unique ethical conflicts that arise in this area. The authors outline approaches to this teaching.