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This paper aims to present a reliability analysis of the slab panel method (SPM) for the design of composite steel floors in severe fires. Rather than seeking to accurately define failure levels, this paper highlights areas of uncertainty in design and their effect on design results, whilst providing approximate reliability levels.

A Monte Carlo simulation has been conducted using the SPM design procedure to produce probability density functions of floor capacity for various floor layouts. Statistical input variables were obtained from the literature. Different configurations, geometries and fire severities are included to demonstrate how predicted floor capacities are influenced.

From the research presented, it is clear that the predicted reliability of SPM systems varies relative to a large number of criteria, but especially parameters related to fire loading. Predicted capacities are shown to be conservative compared to results of furnace and large-scale natural fire tests, which exhibit higher fire resistance. Due to distinct fire hazard categories with associated input values, there are step discontinuities in capacity graphs.

Limited research has been done to date on the reliability of structures in fire as discussed in this paper. It is important to verify the reliability levels of systems to ensure that partial and global factors of safety are adequate. Monte Carlo simulations are shown to be effective for calculating the average floor capacities and associated standard deviations. The presentation of probability density functions for composite floors in severe fires is novel.

This paper presents a comparison, based on real practical case studies, between the simple analytical BRE-Bailey method (BRE-BM) and the advanced finite element model (FEM) Vulcan for the membrane action of composite slab panels with unprotected secondary beams at elevated temperatures. Both approaches predicted the membrane behaviour of the composite slabs, comprising compressive membrane action around the slabs' perimeter and tensile membrane action in the central span region of the slabs. This paper mainly studies the effects of the orientation of unprotected secondary beams and the boundary conditions on tensile membrane action of composite slab panels. The results show that the application of the BRE-BM is generally restricted by the conservative assumption of the maximum allowable vertical displacement. In contrast, the FEM estimates higher load-carrying capacities as well as providing a full displacement-time relationship throughout the heating of the slabs. For slab panels with unprotected secondary beams with an orientation in the short span, tensile membrane action can be easily mobilised without increasing fire protection to the boundary supporting beams. However, the FEM predictions on the slab capacities and deflections in fire are very sensitive to the continuity of the reinforcement over the protected boundary beams.

This paper aims to present a numerical investigation on the fire performance of a single plate shear connection in a steel-framed composite floor. Large-scale fire experiments show that the tensile membrane action of the concrete slab enhances the fire performance of composite floors. The enhancement in the performance is contributed to large slab deflections. However, these deflections cause significant rotations and tensile force in the single plate connection.

A finite element model is constructed, which consists of a secondary steel beam, concrete slab and shear connection components. The interaction between the connection components such as bolts and single plate is defined by contact surfaces. The analysis is conducted in two uncoupled phases: thermal analysis by creating fire boundaries on the composite floor model with convective and radiative heat transfer, and mechanical analysis by considering thermal expansion and changes in the material stiffness and strength due to temperature.

The thermo-mechanical analysis of the composite floor finite element model shows that the structure survives the 2-h Standard fire, but the connection fails by bolt shear and buckling of the connection plate.

This paper investigates the fire performance of a shear connection in a steel-framed concrete slab. Previous work generally focused on the concrete slab behavior only. The originality of the research is that the connection is considered as part of a sub-assembly and is subjected to forces due to concrete and steel beam interaction.

Discusses the 6th ITCRR, its breadth of textile and clothing research activity, plus the encouragement given to workers in this field and its related areas. States that, within the newer research areas under the microscope of the community involved, technical textiles focuses on new, ‘smart’ garments and the initiatives in this field in both the UK and the international community at large. Covers this subject at length.

Looks at the eighth published year of the ITCRR and the research, from far and near, involved in this. Muses on the fact that, though all the usual processes are to the fore, the downside part of the industry is garment making which is the least developed side. Posits that the manufacture of clothing needs to become more technologically advanced as does retailing. Closes by emphasising support for the community in all its efforts.

A simple folding mechanism, which considers the contributions of internal unprotected beams and protected edge beams, has been proposed for isolated slab panels in fire conditions. The current study extends the mechanism to include the reinforcement in the slab as well as continuity across the protected edge beams. Structural failure of the panel depends on the applied loads, the relative beam sizes, their locations within the building, their arrangement in the slab panel, the panel's location and the severity of fire exposure. These factors are considered in the development of a number of collapse mechanisms for verification so they may eventually serve as an additional check within the Bailey-BRE design method, to make it more robust for routine design of composite floors in fire. Comparisons are made with the finite element software Vulcan and other design acceptance criteria.

This study aims to investigate the influence of tendon layout, pre-stressing force, bond condition and concrete spalling on the structural behaviour of two-way post-tensioned flat slabs at elevated temperatures.

Fire tests of four scale specimens of two-way post-tensioned concrete flat slabs were performed and analysed. Three of them were provided with bonded tendons, while the other was unbonded for comparison. The fabrication of specimens, phenomena observed during testing, temperature distributions, deflections and occurrence of concrete spalling were examined.

Different degrees of concrete spalling observed at the soffit had significant effects on the temperature distribution and stress redistribution. This was the major reason for the progressive concrete spalling observed, resulting in loss of structural integrity and stiffness.

The structural behaviour of two-way post-tensioned concrete flat slabs at elevated temperatures is less understood compared to their one-way counterparts. Therefore, the present study has focused on the structural behaviour of two-way post-tensioned concrete flat slabs with bonded tendons in fire, a field in which relatively little information on experimental work can be found.

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.

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.

A new and unexpected mode of damage occurred.

The test results indicate that an alternate reinforcement detail should be used in combination with unprotected beams.

A methodology for producing an elevated-temperature tension stiffening model is presented.

The energy-based stress–strain model of plain concrete developed by Bažant and Oh (1983) was extended to the elevated-temperature domain by developing an analytical formulation for the temperature-dependence of the fracture energy G_f. Then, an elevated-temperature tension stiffening model was developed based on the modification of the proposed elevated-temperature tension softening model.

The proposed tension stiffening model can be used to predict the response of composite floor slabs exposed to fire with great accuracy, provided that the global parameters TS and K_res are adequately calibrated against global structural response data.

In a finite element analysis of reinforced concrete, a tension stiffening model is required as input for concrete to account for actions such as bond slip and tension stiffening. However, an elevated-temperature tension stiffening model does not exist in the research literature. An approach for developing an elevated-temperature tension stiffening model is presented.

This paper aims to investigate the fire performance of composite beams when considering the hogging moment resistance of the fin-plate beam-to-girder joints including the effect of continuity of reinforcements.

Experiments on composite beams with fin-plate joints protected only at the beam ends are conducted. The test parameter is the specification of reinforcement, which affects the rotational restraint of the beam ends. In addition, a simple method for predicting the failure time of the beam using an evaluation model based on the bending moment resistance of the beam considering the hogging moment resistance of the fin-plate joint and the reinforcement is also presented.

The test results indicate that the failure time of the beam is extended by the hogging moment resistance of the joints. This is particularly noticeable when using a reinforcing bar with a large plastic deformation capability. The predicted failure times based on the evaluation method corresponded well with the test results.

Recent studies have proposed large deformation analysis methods using FEM that can be used for fire-resistant design of beams including joints, but these cannot always be applicable in practice due to the cost and its complexity. Our method can consider the hogging moment resistance of the joint and the temperature distribution in the axial direction using a simple method without requirement of FEM.