Valorization of Industrial Waste for the Development of Fire-Resistant Materials

The development of a Fe-based geopolymer and its performance under thermal loading is examined. The geopolymer is developed by mixing industrial waste with a highly alkaline activator, KOH, in the aqueous phase. The mechanical, physical and thermal properties and their respective variation with time are measured. It is shown that the material presents adequate mechanical strength and excellent physical and thermal properties. Then, the geopolymer material is subjected to thermal loading with the modification of a standardized passive fire protection test. The temperature of the exposed surface of the material follows the ISO fire curve that is based on the burning rate of the materials found in general building materials. The material succeeded in the test without failing in any of the criteria concerning the temperature in the unexposed surface of the specimen and its internal integrity. During the test, the temperature in the material-concrete interface remained around 100°C, which is below the test requirements. Thus, the concrete slab protected by the geopolymer did not appear any form of spalling. From this test, it is concluded that the specific geopolymer material by creating a high thermal gradient is able to resist adverse fire scenarios for temperatures up to 1049°C (ISO 834 curve) rendering a proper fire-resistant material for building applications.