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Behaviour of Passive Fire Protection K-Geopolymer under Successive Severe Fire Incidents
Konstantinos Sakkas1, Alexandros Sofianos2, Pavlos Nomikos3
1Laboratory of Tunnelling, School of Mining and Metallurgical Engineering, National Technical University of Athens, 9 Iroon Polytechneiou St, Zografou, Athens 15780, Greece. sakkas@metal.ntua.gr.
Abstract:
The performance of a fire resistant coating for tunnel passive fire protection under successive severe thermal loading is presented. The material falls under the class of potassium based geopolymers (K-geopolymer) and was prepared by mixing ferronickel (FeNi) slag, doped with pure alumina, with a highly alkaline potassium hydroxide aqueous phase. Its performance was assessed by subjecting a concrete slab with a five cm thick K-geopolymer coating layer into successive RijksWaterStaat (RWS) fire incidents. During the first test, the maximum measured temperature in the K-geopolymer/concrete interface was 250 °C, which is 130 °C lower than the RWS test requirement, while, during the second fire test, the maximum temperature was almost 370 °C, which is still lower than the RWS requirement proving the effectiveness of the material as a thermal barrier. In addition, the material retained its structural integrity, during and after the two tests, without showing any mechanical or thermal damages.
