Influence of water content on gas pore pressure in concretes at high temperature

Title: Influence of water content on gas pore pressure in concretes at high temperature
Author(s): J-C. Mindeguia, P. Pimienta, I. Hager, H. Carré
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: 113 - 121
Total Pages: 9
Nb references: 13
Language: English

Abstract: In this paper, results of measurements of gas pore pressure in ordinary concrete (OC) and high performance concrete (HPC) heated up to 600 °C are presented. The same experimental equipment and procedures than Kalifa and co-authors were used, thus enabling the measurement of gas pore pressure and temperature at different depths in prismatic concrete specimens (0.3 x 0.3 x 0.12 m3) heated on one face. The specimens were instrumented during the manufacturing process. The equipment included five probes to simultaneously measure pressure and temperature at different depths. During the test, the specimen was placed on a balance to measure its weight loss in order to provide information on water transfers, which is valuable for validating numerical codes. In the paper, a comparison of results obtained on conditioned in air, pre-dried (at 80 °C) and water saturated samples are presented. As expected, the pressure peaks obtained for pre-dried concretes are the lowest of the three conditioning. Surprisingly, however, the results of gas pore pressure of samples saturated with water exhibited lower values than non pre-treated samples. This result is attributed to crack induced development due to liquid water expansion. Results are compared to previous results on the influence of the heating rate.

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