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The effects of adhesive (layer) on fire performances of structural insulated panel (SIP) have been mostly ignored. This research studied modifications to the epoxy resin adhesive (EA) with expandable graphite (EG), ammonium polyphosphate (APP) and calcium carbonate (CaCO3) to prepare an intumescent flame-retardant epoxy resin adhesive (FREA) which was applied to expanded polystyrene (EPS), a typical core material of SIPs. It was found that the FREA had a char yield of 33% which was 7.6 times of that of EA and a higher viscosity than EA. The limiting oxygen index reached a maximum of 37.7% and UL94 passed the V-0 rating when the EPS was coated with FREA, of which the fire performance was even better than flame-retardant EPS. Additionally, the heat release rate, production rates of CO, CO2 and soot and sample back temperatures were all reduced compared to the EPS coated with EA. Avoiding the sample surface recession in the cone calorimeter, the custom-made spray gun system proves that the FREA can significantly increase the ignition time and lead to self-extinguishment. The degradation products of APP crosslink with CaCO3 to produce phosphates which bond with expanded EG forming the char layer to prevent heat and flame. The use of flame-retardant adhesives can lead to a sufficient fire safety level for the core material without affecting its functions. [ABSTRACT FROM AUTHOR]

Cables are the most common combustibles in nuclear power plants (NPPs) and cable fires are the one of main threaten to the safety of NPPs. Fire characteristics and fire hazards for two typical cables used in NPPs were comparatively studied based on cone calorimeter and cable tray fire tests. The heat release rate (HRR) curves show different patterns, two-peaks and three-peaks for NPP and conventional flame retardant cables, respectively. This difference is attributed to the fire barrier, which distinguishes the burning of sheath and insulation. Moreover, the maximum value of HRR for conventional flame retardant cable is much higher than NPP flame-retardant cable, and the difference is 108 kW m−2. The time from first peak to second peak for NPP flame-retardant cable is approximately four times as conventional flame retardant cable. Based on cable tray fire, the burning time after burner off is much longer for conventional flame retardant cable and its total mass loss is 0.52 kg, which are three times and five times as much as NPP flame-retardant cable, respectively, and it has a self-sustaining stage during cable burning. The above indicates that the NPP flame-retardant cable has less sustained damage, fire development rate and overall fire hazard. In addition, spacing has little effect on the burning time of sheath, but the burning of insulation layer is promoted, the time from first peak to second peak decreases with the increase in spacing. However, the influence of spacing is non-monotonous in cable tray fire, and the burning of cables with 10 mm spacing has higher fire hazard with a maximum mass loss rate. [ABSTRACT FROM AUTHOR]