Geopolymer-Based Mineral Mixtures for Fire and Heating Protection of Concrete and Steel Products of Nuclear Power Plants

The The article presents the results of the use of fireproof coatings and fire-insulating mixtures based on geopolymer to protect concrete and metal structures and products of nuclear power plants from fire and self-heating temperature from the heat release of radionuclides during their decay. According to the results of fire tests, it was determined that the treatment of the concrete surface with a fireproof geopolymer coating with thicknesses from 6 to 18 mm prevents critical heating of the surface of coated products (265.5–334 ℃) to a critical temperature - 380 ℃. It was determined that the temperature of concrete at the depth of reinforcement embedding (25 mm) warms up from 101.8 to 122.6 ℃, which is 4.08–4.91 times less than the critical temperature of metal heating. It has been shown that 6 mm of coating is sufficient for fire protection of external concrete surfaces. And for interior concrete surfaces - 18 mm. The specified thickness of the geopolymer fire protection coating provides protection against the permissible thermal load (250 ℃) on concrete from the heat release of radionuclides during their decay. The developed composition of the geopolymer coating provides a fire resistance class of concrete structures and products not lower than R180. The fire protection effectiveness of mineral mixtures on a geopolymer basis for the protection of metal structures and products has been determined. It is shown that at a thickness of 25 mm, the fireproof coating provides a fire resistance class of R90-R120 and group III of fire protection efficiency. Based on the calculation data in accordance with Eurocode 3, it is established that the coating thickness of 30 mm provides a fire resistance class of R120 and group II of fire protection efficiency. Below.