Fire Test

Recent regulation IEC 60335-1 ed.4 (2008) was introduced for materials used in electric appliance, establishing new limits in Glow Wire Ignition Temperature (GWIT) performance for materials used for electric connectors. Development of new products with high GWIT is possible, but the main issue is to keep good mechanical properties and processability, as well as tracking resistance (Comparative Tracking Index-CTI). Only a

The present research was dedicated to investigation into the strength of timber structures under fire conditions. Two kinds of timber specimens including oak and pine were used. The carried out investigation covered static tests on tensile strength, compressive strength along the grain, compressive strength perpendicular to the grain and flexural strength. The specimens were tested under the temperatures of 50°C, 100°C, 150°C, 200°C and 230°C. The obtained results show that pine specimens have better properties over the entire temperature range in case of tests on tensile and flexural strength. Also, as for these types of strength, oak specimens show a higher strength reduction rate than those of pine specimens, whereas oak specimens have better properties over the entire temperature ranges in case of compressive strength perpendicular to the grain. Based on statistical analysis, a linear expression of the strength reduction coefficient was proposed.

The basic equations, the limitations and the main features of the parametric fire proposed in Annexe B of Eurocode 1 are given. 48 experimental fire tests are used to assess the validity of this model. The model has been applied to these tests and the comparison has been made, for each test, on the maximum temperature in the air and on the maximum temperature calculated in 2 hypothetical steel sections, one thermally protected and one unprotected. The agreement is very poor for the air and for the unprotected steel temperature, and somewhat better for the protected steel temperature. Some proposals are made which allow to improve the agreement, while keeping the same expressions for the parametric fire. These modifications concern the equivalent thermal properties of multi material walls, and the introduction of a minimum duration of the fire and a of a ventilation effect in case of fuel-bed controlled fires.

The structural fire integrity performance of ferrocement jackets was experimentally determined based on its flexural characteristics and the damage after exposure to fire. The main parameter investigated was the heating envelope, consisting of short and long heating durations of 3 and 63 h, where the maximum temperature in both cases was 1060°C. A sandwich-sample configuration was adopted to simulate the actual

ENV 1992-1-2, the fire part of the concrete Eurocode, proposes different tables for the design of simple concrete elements submitted to the ISO fire. Table 4.1 is the table valid for concrete columns. For six fire resistance times Rf = 30, 60, 90, 120, 180 and 240 minutes, and for three load ratio μfi = 0.2, 0.5 and 0.7, an acceptable solution is given in term of the minimum dimension of the section bmin and axis distance a from the re-bar to the edge of the section. The application of this table is not as easy as one could believe at first glance especially when it comes to assessing the fire resistance time of existing elements which are different from the recommended solutions. This is because a double interpolation has to be done, on Rf and on μfi, because the criteria is based on 2 different variables, bmin and a, and because the load ratio is not available from the room temperature design (not to mention the complication created by clause 4.2.3 (6)). In this paper, a graphic i...