| 1. |
- Anderson, Johan, et al.
(författare)
-
Uncertainties in façade fire tests - Measurements and modeling
- 2016
-
Ingår i: MATEC Web of Conferences. - : EDP Sciences.
-
Konferensbidrag (refereegranskat)abstract
- In this paper a comparison between test and modelling results are performed for two large-scale façade fire testing methods, namely SP Fire 105 and BS 8414-1. In order to be able to compare tests and modelling the uncertainties have to be quantified both in the test and the modelling. Here we present a methodology based on deterministic sampling to quantify uncertainties in the modelling input. We find, in general good agreement between the models and the test results. Moreover, temperatures estimated by plate thermometers is indicated to be less sensitive to small variations in model input and is thus suitable for these kind of comparisons.
|
|
| 2. |
|
|
| 3. |
- Jansson McNamee, Robert, et al.
(författare)
-
The function of intumescent paint for steel during different fire exposures
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the present study the behaviour of four intumescent systems for steel was investigated experimentally. The main purpose of the study was to determine the behaviour of the systems during different fire scenarios including standardized furnace testing, tests in cone calorimeter and ad hoc tests including ceiling jets and fire plumes. The experimental campaign shows that two of the investigated systems did perform very poorly in the furnace tests compared to what they were designed for, despite being the systems having the best swelling in the cone calorimeter tests. This highlights the importance of adhesion at high temperature for this type of systems. Since adhesion is crucial a more relevant evaluation for this type of systems ought to be a test where the flows around the specimen can be characterized and controlled, i.e. a ceiling jet or a fire plume scenario. This is especially important as steel protected with intumescent systems are often used in large open spaces where local fire plumes and ceiling jets are expected.Key words: intumescent paint, steel, alternative exposure
|
|
| 4. |
- Lange, David, et al.
(författare)
-
Modelling of hollow core concrete construction exposed to fire
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report summarises the results of a project which was intended to study the response of hollow core and prestressed concrete construction exposed to fire. Two fires in the past 12 years highlighted the susceptibility of this type of construction to fire, a car park fire in Rotterdam and a department store fire in Vantaa. The car park fire has been extensively studied elsewhere and has led to much research on the response of hollow core construction exposed to fire. The department store fire has been less well reported.The report gives a short overview of these two fires, and then reports on a literature review of the response of prestressed and hollow core concrete construction exposed to fire. The comprehensive analyses carried out elsewhere are an excellent starting point for further study.The report then goes on to discuss the application of different concrete models to prestressed concrete construction. Other work reported elsewhere shows that results of modelling prestressed concrete construction exposed to fire is very susceptible to the concrete model which is used, and so finite element modelling of two fire tests of hollow core slabs is carried out to evaluate the impact of the concrete model on this type of construction. It is found that an explicit formulation of transient strain in concrete has a significant impact compared with an implicit formulation of transient strain, in the overall behaviour of the hollow core slab and also in the response of, e.g. the prestessing tendons.Finally, an analytical method for assessing the capacity of prestressed concrete construction under ambient conditions is extended to apply to hollow core slabs exposed to fire. This is used to compare the response of prestressed hollow core slabs to prestressed monolithic slabs exposed to fire and to study different parameters which influence the response and the capacity of hollow core units in fire.Based on the results of the analytical modelling, it can be seen that hollow core concrete construction experiences a far higher thermal gradient and resulting thermal moment than monolithic concrete construction. This is a result of the geometry of the cross section which effectively traps heat in the lower flange. This in turn leads to a faster loss of prestressing force on the cross section than in a monolithic concrete section. This contributes to a faster reduction in the ultimate moment of hollow core slabs compared with monolithic concrete construction.However changing the prestressing tendon depth has a significant effect on the evolution of the ultimate moment under fire exposure. A shallow tendon with little cover has higher capacity at ambient and under fire exposure for a short duration, whereas a tendon with a large amount of cover has a lower ambient capacity, but retains more of this capacity for longer under fire exposure.The analytical method which is proposed is not capable of capturing the nuances in behaviour and response of the finite element method which is reported, nevertheless it is useful in helping to understand the response of prestressed concrete construction exposed to fire. It may also be useful as a screening tool for evaluating the impact of different design options either in hollow core slabs themselves or when making choices in the design phase. However, both the analytical and the numerical modelling suffer from a lack of good quality experimental data which could be used for their evaluation and this should be considered in the future.Key words: prestressed concrete, hollow core slabs, fire, modelling
|
|
