Efficiency of mineral wool slabs for fire protection of structures under accelerated climatic aging

Introduction . The efficiency of fire protection systems for steel structures is determined by their ability to maintain their properties when exposed to external factors, including climatic loads. Natural tests of coating durability require a long time, making accelerated aging methods relevant. The article examines the features of experimental determination of the guaranteed or predicted service life for a structural fire protection based on mineral wool slabs for metal building structures, depending on operating conditions. Aim . To study the efficiency of structural fire protection based on mineral wool slabs during climatic aging under UKhL2 and UKhL3 operating conditions according to State Standard 15150-69 using the example of a contemporary coating. Materials and methods. The performed work includes cyclic artificial aging of a structural fire-protective coating for 5, 10, 15, 20, and 25 years according to the methodology of State Standard R 71618-2024. The resistance to climatic factors and maintenance of fire-protective properties during operation are assessed using three methods: measurement of thermal conductivity according to State Standard 7076-99, thermal analysis according to State Standard R 53293-2009, and assessment of fire protection efficiency according to State Standard R 53295-2009. The study uses 600 × 600 × 5 mm sheets of 08kp and 08ps steel according to State Standard 16523-97 and State Standard 9045-93 with applied ET-METALL structural system, including 30 mm EURO-LIT mineral wool thermal insulation slabs and 2 mm PLAZAS heat-resistant adhesive composition. Results . The fire protection efficiency decreasing with an increase in the number of artificial aging cycles is established 16.7 % lower than the control sample at 125 cycles (25 years). Conclusions . The predicted service life of the ET-METALL structural system outdoors under a canopy (UKhL2) and inside buildings with natural ventilation (UKhL3) is at least 25 years.