The age effect on fire spalling of concrete

Title: The age effect on fire spalling of concrete
Author(s): L. Boström, R. Jansson
Paper category : conference
Book title: 2nd International RILEM Workshop on Concrete Spalling due to Fire Exposure
Editor(s): E.A.B. Koenders and F. Dehn
ISBN: 978-2-35158-118-6
e-ISBN: 978-2-35158-119-3
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 33 - 41
Total Pages: 9
Nb references: 16
Language: English

Abstract: The age of a test specimen at the time of testing is a factor that is much debated when looking at the spalling sensitivity of concrete. In general when the fire resistance of a test specimen is determined it is assumed to be in equilibrium with the surrounding relative humidity. This is in practice impossible when a dense concrete specimen with a thick crosssection is tested. The option of rapid drying at elevated temperatures has been shown to change the behaviour compared with a specimen that is naturally dried [1] and is, therefore, not a suitable solution when testing the fire resistance of concrete elements.

Complementary tests on concrete specimens from two previous test campaigns [2, 3], that originally included fire tests of more than 60 different concrete mixes tested in over 200 fire tests, have been conducted after an extended storage time of 3-5 years. Included in the new test series are both larg slabs, 1700 × 1200 × 200 mm, and small specimens, 500 × 600 × 200 mm.

The results show that the maximum spalling depth is reduced, to some extent, by longer storage time but the reduction differs between mixes. It is shown that after 5 years storage, severe spalling can occur for some concrete qualities. It was also found that the type of loading arrangement used when testing the spalling behaviour can influence the amount of spalling and the spalling depth to a large extent.

Online publication: 2012-01-17
Publication type : full_text
Public price (Euros): 0.00