The Standard Fire Testing and Numerical Modelling of the Behavior of Calcium Silicate Board Metallic-Framework Drywall Assembly with Junction Box

Abstract

The metallic-framework drywall is used as the specimens in this research. The standard fire test and finite element simulation were performed once on 300 cm × 300 cm area specimen and twice on 100 cm × 100 cm area specimens, to quantify and evaluate the effect of the junction boxes on the fireproof property after being embedded into the metallic-framework drywall. The results of the experiment show that the temperature of unexposed surface rises faster due to the higher thermal conductivity of the internal metal junction box. The general junction box whose material is PVC can be softened off when heated, affecting the integrity of the firewall and also leading to rapid transfer to the unexposed surface. The prediction of finite element simulation temperature is highly correlated with the results of the real experiment. It is effective to strengthen the original weaknesses by adding a calcium silicate board behind the junction box and using metal panels instead of PVC. The temperature of the temperature junction box surface which is the highest temperature point of unexposed surface decreased most significantly at 72.9°C after the reinforcement. In addition, after reinforcement, the fire resistance time can reach to 1 hour by inserting the junction box into the metallic-framework drywall.