A Design Model for the Fire Resistance of Timber-Concrete Composite Slabs

Purpose Insulation materials’ contribution to the fire resistance of timber frame assemblies may vary considerably. At present, Eurocode 5 provides a model for fire design of the load-bearing function of timber frame assemblies with cavities completely filled with stone wool. Very little is known about the fire protection provided by other insulation materials. An improved design model which has the potential to consider the contribution of any insulation material has been introduced by the authors. This paper aims to analyze the parameters that describe in a universal way the protection against the charring given by different insulations not included in Eurocode 5. Design/methodology/approach A series of model-scale furnace tests of floor specimens for three different insulation materials were carried out. An analysis on the charring depth of the residual cross-sections was conducted by means of a resistograph device. Findings The study explains the criteria and procedure followed to derive the coefficients for the improved design model for three insulations involved in the study. Originality/value This research study involves a large experimental work which forms the basis of the proposed design model. This study presents an important step for fire resistance calculations of timber frame assemblies.

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Concept of a Design Model for Shear Loaded Composite Slabs

Proceedings of the 10th International Conference on Advances in Steel Concrete Composite and Hybrid Structures ◽

10.3850/978-981-07-2615-7_049 ◽

2012 ◽

Author(s):

Hartmeyer Simon ◽

Kurz Wolfgang

Keyword(s):

Design Model ◽

Composite Slabs

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Fire resistance of composite slabs with steel deck under natural fire

Journal of Structural Fire Engineering ◽

10.1108/jsfe-02-2021-0009 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Paulo A.G. Piloto ◽

Carlos Balsa ◽

Felipe Macedo Macêdo Gomes ◽

Bergson Matias

Keyword(s):

Fire Resistance ◽

Numerical Models ◽

Three Dimensional ◽

Composite Slab ◽

Content Type ◽

Natural Fire ◽

Fire Scenario ◽

Composite Slabs ◽

Cooling Phase ◽

Steel Deck

PurposeMost of the numerical research and experiments on composite slabs with a steel deck have been developed to study the effect of fire during the heating phase. This manuscript aims to describe the thermal behaviour of composite slabs when submitted to different fire scenarios, considering the heating and cooling phase.Design/methodology/approachThree-dimensional numerical models, based on finite elements, are developed to analyse the temperatures inside the composite slab and, consequently, to estimate the fire resistance, considering the insulation criteria (I). The numerical methods developed are validated with experimental results available in the literature. In addition, this paper presents a parametric study of the effects on fire resistance caused by the thickness of the concrete part of the slab as well as the natural fire scenario.FindingsThe results show that, depending on the fire scenario, the fire resistance criterion can be reached during the cooling phase, especially for the thickest composite slabs. Based on the results, new coefficients are proposed for the original simplified model, proposed by the standard.Originality/valueThe developed numerical models allow us to realistically simulate the thermal effects caused by a natural fire in a composite slab and the new proposal enables us to estimate the fire resistance time of composite slabs with a steel deck, even if it occurs in the cooling phase.

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Numerical simulation of the fire resistance of composite slabs with steel deck

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.23.11889 ◽

2018 ◽

Vol 7 (2.23) ◽

pp. 83 ◽

Cited By ~ 1

Author(s):

Paulo A. G. Piloto ◽

Lucas M.S. Prates ◽

Carlos Balsa ◽

Ronaldo Rigobello

Keyword(s):

Numerical Simulation ◽

Fire Resistance ◽

Calculation Method ◽

Simple Calculation ◽

Concrete Layer ◽

Composite Slabs ◽

Composite Solution ◽

Steel Deck ◽

Loadbearing Capacity ◽

Methods Numerical

This investigation is related with the fire resistance of composite slabs with steel deck. This composite solution consists of a concrete topping cast on the top of a steel deck. The concrete is typically reinforced with a steel mesh and may also contain individual rebars. The deck also acts as reinforcement and may be exposed to accidental fire conditions from the bottom. This composite solution is widely used in every type of buildings and requires fire resistance, in accordance to regulations. The fire resistance is specified by the loadbearing capacity (R), insulation (I) and integrity (E). The fire rating for (R) and (E) is not in the scope of this investigation. The fire rating for insulation (I) is evaluated by two different methods (numerical simulation and simple calculation). The fire rating is calculated for 32 different geometric configuration, in order to evaluate the effect of the thickness of the concrete layer and the thickness of steel deck. The fire resistance (I) increases with the thickness of the concrete when using both methods, but the simple calculation method seems to be unsafe for all the cases, requiring a revision for the formulae presented in Annex D of EN1994-1-2. A new proposal is presented.

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Improved calculation method for insulation-based fire resistance of composite slabs

Fire Safety Journal ◽

10.1016/j.firesaf.2019.02.013 ◽

2019 ◽

Vol 105 ◽

pp. 144-153 ◽

Cited By ~ 3

Author(s):

Jian Jiang ◽

Adam Pintar ◽

Jonathan M. Weigand ◽

Joseph A. Main ◽

Fahim Sadek

Keyword(s):

Fire Resistance ◽

Calculation Method ◽

Composite Slabs

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ANALYSIS OF THE VERTICAL SHEAR DESIGN MODEL FOR STEEL-CONCRETE COMPOSITE SLABS

ce/papers ◽

10.1002/cepa.540 ◽

2017 ◽

Vol 1 (4) ◽

pp. 405-414 ◽

Cited By ~ 1

Author(s):

Miguel Pereira ◽

Rui Simões ◽

João Duarte

Keyword(s):

Design Model ◽

Vertical Shear ◽

Shear Design ◽

Composite Slabs

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Effect of the load level on the resistance of composite slabs with steel decking under fire conditions

Journal of Fire Sciences ◽

10.1177/0734904119892210 ◽

2020 ◽

Vol 38 (2) ◽

pp. 212-231

Author(s):

Paulo AG Piloto ◽

Carlos Balsa ◽

Lucas MC Santos ◽

Érica FA Kimura

Keyword(s):

Experimental Data ◽

Fire Resistance ◽

Parametric Analysis ◽

Simple Calculation ◽

Load Level ◽

Calculation Methods ◽

Composite Slabs ◽

Perfect Contact ◽

Steel Deck ◽

Calculation Models

The fire resistance of composite slabs with steel decking, in Europe, is usually defined using simple calculation models provided by the Eurocode EN 1994-1-2. For assessing the methodology of these simple calculation methods, a new advanced calculation method is presented, using the software ANSYS. The numerical model is first validated with experimental data reported on bibliography and then a parametric analysis is conducted to better understand the effect of the load level on the composite structure under fire. The validation of the simulations consisted of three different models: the first model considers perfect contact between the steel deck and the concrete topping, and the two following models consider the existence of an air gap between these materials, acting as a thermal resistance on the temperature field through the thickness of the slab. The numerical results show good approximation to the experimental results, mainly when using the non-perfect contact model, reaching 3.88% and 16.91% of difference with respect to the insulation and load-bearing criteria, respectively. Based on the validation models, a parametric study is presented, modifying the load level from 10% up to 75%. New simple calculation models are presented to define the fire resistance of composite slabs, considering the load level, and the debonding effect between the concrete and the steel deck.

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