Reinforced concrete slabs strengthened with textile reinforced concrete subjected to fire

Title: Reinforced concrete slabs strengthened with textile reinforced concrete subjected to fire
Author(s): D. Ehlig and S. Hothan
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: 419 - 426
Total Pages: 8
Nb references: 8
Language: English

Abstract: Thin layers of textile reinforced concrete (TRC) can be used as strengthening for reinforced concrete (RC) slabs or beams to increase their load-bearing capacity. The concrete matrix consists of a fine-grained concrete with a thickness of 8 to 15 mm. Information on the behaviour of strengthened structures subjected to fire is of particular interest for practical applications of this innovative construction method. A total of 7 RC slabs with steel reinforcement were produced: 2 slabs were used as reference and 5 slabs were strengthened with three layers of textile reinforcement. Ultimate capacity of reference slabs and particular TRC strengthened slabs was determined from static load results from 4-point-bending tests.
Fire tests on these slabs were carried out with utilization factors using a standard temperature curve (ISO-834-1) for fire testing. Test loads varied between 0 % and 65 % of ultimate load.
To detect temperatures during fire exposure thermocouples were arranged throughout the cross-section of the slabs. Depending on the utilization the slabs were exposed to fire for 30 minutes or for 60 minutes. In some cases bending failure occurred, in other cases the slabs survived. None of the specimens exhibited any visual damage or concrete spalling during fire exposure. Results of deformation measurements and residual strength measurements are presented. Even though mechanisms are not fully understood, it is important to discuss the presumable reasons for the surprisingly positive test results. It is presumed that the key mechanisms contributing to the outstanding fire resistance capability presented are: superior crack control of the TRC and load redistribution between textile and steel reinforcement as well as the primary load transfer directly into the slabs.

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