scholarly journals Transverse Distribution of Concentrated Loads on Timber Composite Floors

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1421
Author(s):  
Sandra Monteiro ◽  
Alfredo Dias ◽  
Sérgio Lopes

Timber-concrete composite floors can be seen as bi-dimensional elements constituted by repeatable longitudinal elements (timber beams) connected through an element capable to spread the load on the transverse direction (concrete slab). This is usually a fact to “take advantage of” in terms of design, in the light of current regulations, with the analysis of a “T-shape” beam. Nevertheless, when concerning the action of concentrated loads, considering them supported entirely by the beam to which they are applied can result in a disadvantage rather than an advantage. This study focus on the distribution of load in the transverse direction when composite floors are subjected to concentrated loads. There were analyzed not only timber-concrete composite floors, that already have proven their value, but also relatively new solutions as those using cross laminated timber (CLT) combined with steel beams. The results show that the load received by “the loaded beam” can be far from 100%.

2021 ◽  
Author(s):  
Sara Bottaro ◽  
David Owolabi ◽  
Cristiano Loss

<p>Timber-based composite floors are gaining ascendancy as potential competitors with mainstream steel-concrete composites due to the increasing emphasis on sustainability in the construction industry. This paper investigates the vibration serviceability performance of an innovative prefabricated timber-steel composite floor module. The floor features a cross-laminated timber (CLT) panel joined to cold-formed steel beams using self-tapping screws as shear connectors. The vibration response of the floor module is simulated through the finite element method considering both modal and transient analyses, and its structural performance is evaluated using criteria specified in international design codes and standards. The results provide insight into the vibration behaviour of steel-timber composite floors in residential applications.</p>


2014 ◽  
Vol 601 ◽  
pp. 231-234
Author(s):  
Cristian Lucian Ghindea ◽  
Dan Cretu ◽  
Monica Popescu ◽  
Radu Cruciat ◽  
Elena Tulei

As a general trend, in order to reduce material consumption or to reduce the mass of the structures, composite floor slabs solutions are used to achieve large spans floor slabs. This solutions led to floors sensitive to vibrations induced generally by human activities. As a verification of the design concepts of the composite floors, usually, it is recommended a further examination of the floor after completion by experimental tests. Although the experimental values of the dynamic response of the floor are uniquely determined, the processing can take two directions of evaluation. The first direction consist in determining the dynamic characteristics of the floor and their comparison with the design values. Another way that can be followed in the processing of the experimental results is to consider the human perception and comfort to the vibration on floors. The paper aims to present a case study on a composite floor, with steel beams and concrete slab, tested on-site. Both aspects of data processing are analyzed, in terms of the structural element, and in terms of the effect on human perception and comfort. Experimentally obtained values for the dynamic characteristics of the floor are compared with numerical values from finite element analysis, while the second type of characteristic values are compared with various human comfort threshold values found in international standards.


2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Faraz Sadeghi ◽  
Ahmad Beng Hong Kueh

Footbridge responses under loads induced by human remain amongst the least explored matters, due to various uncertainties in determining the description of the imposed loadings. To address this gap, serviceability of an existing composite footbridge under human walking and running loadings is analyzed dynamically in this paper employing a finite element approach. The composite footbridge is made-up of a reinforced concrete slab simply supported at two ends on top of two T-section steel beams. To model the walking and running loads, a harmonic force function is applied as the vibration source at the center of the bridge. In the model verification, the computed natural frequency of footbridge exhibits a good agreement with that reported in literature. The vibration responses in terms of peak acceleration and displacement are computed, from which they are then compared with the current design standards for assessment. It is found that the maximum accelerations and displacements of composite footbridge in presence of excitations from one person walking and running satisfy the serviceability limitation recommended by the existing codes of practice. In conclusion, the studied footbridge offers sufficient human safety and comfort against vibration under investigated load prescription.


1983 ◽  
Vol 10 (2) ◽  
pp. 192-204 ◽  
Author(s):  
C. J. Montgomery ◽  
G. L. Kulak ◽  
G. Shwartsburd

A case history of a steel beam – concrete slab composite floor system which had deflection serviceability problems is presented. Load tests carried out to assess the structural adequacy of the floor system are described. Practical methods for predicting elastic, creep, and shrinkage deflections of composite floors are summarized and recommendations for design are made.


2014 ◽  
Vol 5 (2) ◽  
pp. 125-134
Author(s):  
Jochen Zehfuß ◽  
Christoph Klinzmann ◽  
Karen Paliga

The objective of this article is the illustration of the calculation of natural fires and fire resistance of structural members based on the Eurocodes of two types of special structures, in this case a railway bridge and an airplane hangar. The railway bridge has a width of nearly 70 meters and consists of steel beams and a massive concrete slab that are supported by massive columns and walls and for that reason can be compared to a tunnel. The load-bearing structure of the roof of the hangars is made of steel and is supported by steel columns. The choice of a fire scenario on the safe side is crucial for the design process of the unprotected steel structure.


Author(s):  
Adrian Ciutina ◽  
Cristian Vulcu ◽  
Rafaela Don

The slim-floor building system is attractive to constructors and architects due to the integration of steel beam in the overall height of the floor, which leads to additional floor-to-floor space, used mostly in acquiring additional storeys. The concrete slab offers natural fire protection for steel beams, while the use of novel corrugated steel sheeting reduces the concrete volume, and replaces the secondary beams (for usual spans of steel structures). Currently the slim-floor solutions are applied in non-seismic regions, and there are few studies that consider continuous or semi-continuous fixing of slim-floor beams. The present study was performed with the aim to develop reliable end-plate bolted connections for slim-floor beams, capable of being applicable to buildings located in areas with seismic hazard. It is based on numerical finite element analysis, developed in two stages. In a first stage, a finite element numerical model was calibrated based on a four point bending test of a slim-floor beam. Further, a case study was analysed for the investigation of beam-to-column joints with moment resisting connections between slim-floor beams and columns. The response was investigated considering both sagging and hogging bending moment. The results are analysed in terms of moment-rotation curve characteristics and failure mechanism. 


2017 ◽  
Vol 27 (4) ◽  
pp. 143-156 ◽  
Author(s):  
Maciej Szumigała ◽  
Ewa Szumigała ◽  
Łukasz Polus

Abstract This paper presents an analysis of timber-concrete composite beams. Said composite beams consist of rectangular timber beams and concrete slabs poured into the steel sheeting. The concrete slab is connected with the timber beam using special shear connectors. The authors of this article are trying to patent these connectors. The article contains results from a numerical analysis. It is demonstrated that the type of steel sheeting used as a lost formwork has an influence on the load-bearing capacity and stiffness of the timber-concrete composite beams.


Buildings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 32
Author(s):  
Sandra Monteiro ◽  
Alfredo Dias ◽  
Sérgio Lopes

Timber-concrete composite (TCC) solutions are not a novelty. They were scientifically referred to at the beginning of the 20th century and they have proven their value in recent decades. Regarding a TCC floor at the design stage, there are some assumptions, at the standard level, concerning the action of concentrated loads which may be far from reality, specifically those associating the entire load to the beam over which it is applied. This naturally oversizes the beam and affects how the load is distributed transversally, affecting the TCC solution economically and mechanically. Efforts have been made to clarify how concentrated loads are distributed, in the transverse direction, on TCC floors. Real-scale floor specimens were produced and tested subjected to concentrated (point and line) loads. Moreover, a Finite Element (FE)-based model was developed and validated and the results were collected. These results show that the “loaded beam” can receive less than 50% of the concentrated point load (when concerning the inner beams of a medium-span floor, 4.00 m). Aiming at reproducing these findings on the design of these floors, a simplified equation to predict the percentage of load received by each beam as a function of the floor span, the transversal position of the beam, and the thickness of the concrete layer was suggested.


2019 ◽  
Vol 97 ◽  
pp. 06022
Author(s):  
Alexander Tusnin ◽  
Alexey Kolyago

Reinforced concrete floors and steel beams are widely used in buildings and structures for various purposes. Reinforced concrete overlaps can be cast-in or precast of hollow-core slabs. The most effective floors in which the concrete slab is located in the compressed area of cross-section, in steel beams in the tension zone, and shifting forces, arising between concrete slab and the steel beam, are perceived by anchors. Precast slabs in comparison with cast-in ones have less labor-intensive performance, the beam spacing is equal to the span of reinforced concrete slabs, there are no intermediate beams in such overlaps, that allows to reduce the floor thickness. The inclusion of precast in steel-concrete cross-section requires joints with steel beams, which requires using of special anchors. Anchor perceives shear forces and ensures the joint operation of the plate and the steel beam. In addition, for beams with narrow flange, the anchor device can provide the required width of the support slabs. The calculation of the attachment points of the anchors to the steel beam is carried out using three variants of calculation methods, which allow to determine the forces acting on the anchor. For practical application, a wire-element model has been proposed and managed to get forces in a steel beam, slab and anchors the width of the slab recommended by the standards should be included in the calculation model.


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