Fire Spalling of Self-Compacting Concrete Mixtures with Different Limestone Powder Contents

Author(s): Steve Werner, Wolfram Schmidt, Stephan Pirskawetz, Andreas Rogge
Paper category: Conference
Book Title: 8th International RILEM Symposium on Self-Compacting Concrete - SCC 2016
Editor: Kamal H. Khayat
ISBN: 978-2-35158-156-8
e-ISBN: 978-2-35158-157-5
Publisher: RILEM Publications SARL
Publication year: 2016
Pages: 353-363
Total Pages: 11
Language: English

Abstract: Self-compacting concrete typically contains a higher content of powder materials than normal concrete. Furthermore it is assumed that the use of superplasticizers yields a more homogenous microstructure in the hardened paste. Both aspects generate a very dense microstructure, which can be assumed to cause material behaviour that differs from than normal concrete when it is exposed to elevated temperatures. However, the paste volumes in SCC can vary significantly based on the mixture composition. At a low paste volumes SCC can be very similar to normal concrete at hardened state while it can vary greatly at higher paste volumes. Since the high temperature behaviour of concrete is strongly affected by the different physical behaviour of the paste and the aggregates, it is likely that the high temperature behaviour is consequently strongly affected by the ratio of these mixture components. In the present study different SCC mixtures were observed with similar mechanical properties, but with significantly differing paste to aggregate ratios. Based on observations of the heat evolution at the fire exposed surface and at different depths inside the specimens as well as based on photogrammetric observations of the spalled dimensions, the results indicate that with increasing paste volumes the heat conductivity is reduced and as a result concrete with higher paste to aggregate ratios shows less spalling.

Online publication: 2016
Publication Type: full_text
Public price (Euros): 0.00