Behavior of bolted timber joints subjected to high temperatures

This paper presents experimental research on the behavior of bolted timber joints subjected to high temperatures. Tests for the determination of the embedment strength parallel to the timber grain and the load-bearing capacity of single- and three-bolt joints were carried out. The tested temperatures were 20, 50, 100, 150, 200, and 230 A degrees C. The specimens were made of Pinus taeda timber with a density varying from 427 to 524 kg/m(3) and moisture content of 12% at 20 A degrees C. The results have shown that the temperature and moisture content significantly influence the load-bearing capacity of the joints. Higher temperature leads to a nonlinear decrease of resistance, with minimum values at 50 and 100 A degrees C for the single- and three-bolt timber joints, respectively. This behavior is associated with degradation of the polymers and changes in the moisture content of the timber.