Experimental Study on Fire Resistance of One-Way Straight and Through Mortise-Tenon Timber Joints

Abstract

Fire is one of the most frequent disasters in the world. Many traditional timber buildings were destroyed by fire, causing a large amount of culture and heritage loss. Timber joints play an important role in the stability of whole timber structures. The temperature development and fire resistance of mortise-tenon joints exposed to fire were experimentally studied in this paper. The effects of joint type and load ratio on their fire resistance were considered. Results showed that the capacity of one-way straight mortise-tenon joint was higher than through mortise-tenon joints. Temperature increased with increasing fire exposure time and decreased very slowly after the fire was stopped. The closer the thermocouples to the surface of timber beam and column were, the higher their temperature was. It was observed that for the mortise-tenon joints of the same type, the fire resistance decreased with load ratios. For the mortise-tenon joints subjected to the same load ratios, the fire resistance of one-way straight mortise-tenon joint was slightly higher than through mortise-tenon joints. The fire resistance of through mortise-tenon joints tested under the load ratio of 0.3 and 0.5 were 25 min and 20 min respectively, while the fire resistance of one-way straight mortise-tenon joints tested under the load ratio of 0.5 was 24 min.