scholarly journals CRITICAL TEMPERATURE OF STEEL BEAMS ON THE BASIS OF A LOAD-BEARING FIRE TEST OF 2-STOREY RIGID STEEL FRAME

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


2020 ◽  
Vol 10 (5) ◽  
pp. 1763
Author(s):  
Albert Albareda-Valls ◽  
Alicia Rivera-Rogel ◽  
Ignacio Costales-Calvo ◽  
David García-Carrera

Ceramic-reinforced slabs were widely used in Spain during the second half of the 20th century, especially for industrial buildings. This solution was popular due to the lack of materials at that time, as it requires almost no concrete and low ratios of reinforcement. In this study, we present and discuss the results of a real load-bearing test of a real ceramic-reinforced slab, which was loaded and reloaded cyclically for a duration of one week in order to describe any damage under a high-demand loading series. Due to the design of these slabs, the structural response is based more on shear than on bending due to the low levels of concrete and the geometry and location of re-bars. The low ratio of concrete makes these slabs ideal for short-span structures, mainly combined with steel or RC frames. The slab which was analyzed in this study covers a span of 4.88 m between two steel I-beams (IPN400), and corresponds to a building from the mid-1960s in the city of Igualada (Barcelona, Spain). A load-bearing test was carried out up to 7.50 kN/m2 by using two-story sacks full of sand. The supporting steel beams were propped up in order to avoid any interference in the results of the test; without the shoring of the steel structure, deflections would come from the combination of the ceramic slab together with the steel profiles. A process of loading and unloading was repeated for a duration of six days in order to describe the cyclic response of the slab under high levels of loading. Finally, vibration analysis of the slab was also done; the higher the load applied, the higher the fundamental frequency of the cross section, which is more comfortable in terms of serviceability.


Author(s):  
Petr Kuklík ◽  
Magdaléna Charvátová

The paper is focused on the influence of fire resistant coatings used on OSB boards on the fire resistance of entire light timber frame wall assemblies. Two fire tests were performed in the fire test laboratory of PAVUS, a.s. in Veselí nad Lužnicí. The fire tests were performed on a load bearing wall. The wall dimensions were 3.0 (depth) x 3.0 (height) m. According to EN 1995-1-2, the calculation for fire paints and coatings is not possible. The aim of the paper is the determination of the influence of this type of coating on the OSB board’s charring rate, the determination of the start of charring of a timber stud and the fire resistance of the whole construction.


2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Qi-shi Zhou ◽  
Hua-wei Fu ◽  
Xu-hong Zhou ◽  
Yu-jie Yu ◽  
Qian-ren Wang

Through-core connection has been proven to be an ideal solution to ensure a rigid connection between steel beams and CFST columns. However, the traditional through-core connection sometimes encounters concrete filling problems. A modified through-core connection design with details of reduced flange width was therefore proposed. Through-core reinforcements were added as supplements for tension load transfer. The monotonic loading tests and comprehensive FE simulations were performed to investigate the load bearing performance and working mechanism of this modified connection. The results indicated that the modified through-core connection presented plasticity hinge failure at the beam end and crack formulation and progradation at the RC slab. The reduced flange width reduced the strength of the connection, but the reduction extent was limited. Due to the through-core construction, the majority of internal forces at the beam were directly transferred into the column. The through-core reinforcement can effectively participate in load bearing after the connection yields. The flange width reduction extent and the length of the reduction region must be controlled to ensure sufficient connection strength. The number of shear studs and TC reinforcements can influence the load bearing ability, and design suggestions are provided for the modified through-core connection.


2020 ◽  
Vol 38 (2) ◽  
pp. 136-155
Author(s):  
Seddik M Khetata ◽  
Paulo AG Piloto ◽  
Ana BR Gavilán

The light steel frame walls are mostly used for non-load bearing applications. The light steel framed walls are made with studs and tracks that require fire protection, normally achieved by single plasterboard, by composite protection layers or by insulation of the cavity. The partition walls are fire rated to resist by integrity and insulation. Seven small-scale specimens were tested to define the fire resistance of non-load bearing light steel frame walls made with different materials. All tests were validated using two-dimensional numerical models, based on the finite-element method, the finite-volume method and hybrid finite-element method. A good agreement was achieved between the numerical and the experimental results from fire tests. The fire resistance increases with the number of studs and also with the thickness of the protection layers. The hybrid finite-element method solution method looks to be the best approximation model to predict fire resistance.


2020 ◽  
Vol 313 ◽  
pp. 00032
Author(s):  
Przemysław Palacz ◽  
Izabela Major

The paper presents a solution that includes strengthening the connection of a support column with beams from both sides, placed in a vertical plane together with the pole. All the bar elements connected in the analyzed node were made of hot-rolled steel I-sections. Due to the need to increase the load on the joined beams to the pole, load-bearing capacity of the primary connection is lost, which necessitates the reinforcement of the existing connection. The analysis carried out in this paper shown exceeding the allowable stresses in the column web at the place of joining the beams. The calculations made in this paper showed the possibilities of restoring the safe operation of the connection node in question, by introducing elements increasing its load-bearing capacity. In addition to analytical calculations, numerical analysis was also performed using the ADINA program.


2018 ◽  
Vol 763 ◽  
pp. 1113-1120
Author(s):  
Giuseppe Marzano ◽  
Lei Zhang ◽  
Yuga Sasaki ◽  
Masahiro Kurata

In steel moment-resisting frames, concrete floor slab attached to steel beams contributes a larger stiffness and moment strength under positive bending. The composite action shifts up the section neutral axis and increases the risk of fracture at the bottom flanges of beam ends. A retrofit technique, named minimal disturbance arm damper (MDAD), is proposed as a solution to restrain the local deformation at beam ends and reduce the frame responses with moderate increase in stiffness, strength and damping. MDAD can retrofit steel frames rapidly by only using the bolt connections and preserve the open space of the frames. In this paper, the effectiveness of MDAD in improving the seismic performance of the steel frame was experimentally and numerically examined through the application to half-scaled multi-span specimens. The test and numerical results both showed significant benefits of MDAD in reducing the positive bending moment at beam ends, delaying the fractures at the bottom flange of beam ends and providing alternative load–carrying paths after fracture to prevent strength reduction.


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