Fire-resistant performance of a laminated veneer lumber joint with metal plate connectors protected with graphite phenolic sphere sheeting

Creep under fire of laminated veneer lumber (LVL) joined with metal connect ors was studied. The fire-resistant performance of LVL butt joints connecte d with metal plates protected with graphite phenolic sphere (GPS) sheeting was discussed. The GPS sheeting was overlaid on the joint in different size s and locations. The joint was exposed to a burner with a top flame tempera ture of 800 degreesC and loaded with a load of 200N to test for creep under fire. The results showed that the fire-resistant performance of the joint was markedly improved by the sheeting. The size and location of the GPS she et significantly affected the time to rupture of the specimen, which was si x times longer than that without GPS. Temperature measurements at the joint showed that the GPS sheeting distributed the heat along the surface and de layed failure. Thermographic images and analyses clarified the improvement in fire-resistant properties due to GPS.