Reaction to fire tests. Measurement of material properties using a fire propagation apparatus

2011 ◽  
2018 ◽  
Vol 163 ◽  
pp. 07004 ◽  
Author(s):  
Wojciech Węgrzyński ◽  
Piotr Turkowski

The origins of standardised fire testing can be traced back to 1870’s, and the origin of the standard temperature-time curve to 1917. This approach, based on a 19th-century intuition is still in use up to this day, to design the 21st-century structures. Standardized fire-testing ultimately disregards the conservation of energy in the fire, as in every test the resulting temperature of the test must be the same (precisely as the temp.-time curve). To maintain this, different amount of heat is required in every test, which means that every time a different fire is modelled within the furnace. The differences between furnace fire sizes are ignored in the certification process, but can be interesting for fire researchers to understand how different materials behave in fire conditions. In this paper, Authors explore this topic by investigating the energy balance within the furnace, and comparing different fire tests together.


2019 ◽  
Vol 107 ◽  
pp. 161-169 ◽  
Author(s):  
R. Fahrni ◽  
M. Klippel ◽  
A. Just ◽  
A. Ollino ◽  
A. Frangi

2006 ◽  
Vol 321-323 ◽  
pp. 322-327 ◽  
Author(s):  
Soo Ho Chang ◽  
Soon Wook Choi ◽  
Gyu Jin Bae

To protect underground structures and passengers from fire, it is essential to characterize fire-induced damage on the construction materials for underground structures. However, it is almost impossible and uneconomical to carry out full-scale fire tests in tunnels that are under public usage. In this study, a high temperature furnace capable of simulating RABT (Richtlinien für die Ausstattung und den Betrieb von Straßentunneln) fire curve was newly designed and manufactured. In the fire tests, furnace temperature is set to reach 1,200 within five minutes after ignition. The temperature of 1,200 was maintained for one hour, and the fire was extinguished after two hours had elapsed. From the temperature measurement by thermocouples embedded in test specimens, the depth of lost concrete was estimated to reach approximately 20 cm from the surface that was exposed to fire. In addition, the alteration of physico-mechanical properties and microstructures of concrete segments after fire tests were investigated from core specimens. The results show that the deterioration of material properties was up to 10 cm from the surface of the remaining concrete block


Author(s):  
C.L. Briant

Grain boundary segregation is the process by which solute elements in a material diffuse to the grain boundaries, become trapped there, and increase their local concentration at the boundary over that in the bulk. As a result of this process this local concentration of the segregant at the grain boundary can be many orders of magnitude greater than the bulk concentration of the segregant. The importance of this problem lies in the fact that grain boundary segregation can affect many material properties such as fracture, corrosion, and grain growth.One of the best ways to study grain boundary segregation is with Auger electron spectroscopy. This spectroscopy is an extremely surface sensitive technique. When it is used to study grain boundary segregation the sample must first be fractured intergranularly in the high vacuum spectrometer. This fracture surface is then the one that is analyzed. The development of scanning Auger spectrometers have allowed researchers to first image the fracture surface that is created and then to perform analyses on individual grain boundaries.


Author(s):  
Brian Ralph ◽  
Barlow Claire ◽  
Nicola Ecob

This brief review seeks to summarize some of the main property changes which may be induced by altering the grain structure of materials. Where appropriate an interpretation is given of these changes in terms of current theories of grain boundary structure, and some examples from current studies are presented at the end of this paper.


2016 ◽  
Author(s):  
Frank Malgo ◽  
Neveen A T Hamdy ◽  
Alberto M Pereira ◽  
Nienke R Biermasz ◽  
Natasha M Appelman-Dijkstra

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