Effect of cold temperatures on the shear behavior of glued laminated beams

- Twelve glulam beams with varying moisture contents were tested at three temperatures.
- Strength and stiffness of the beams were found to increase with decreasing temperature.
- Effect of cold was more pronounced in beams with higher moisture contents.
- The failure mechanism of the beams switched from shear to tension at extremely low temperatures.
- Shear failures did not occur due to failure of adhesives.

This study evaluated the effects of subfreezing temperatures and moisture content on the shear behavior of glulam beams. Full-scale glulam beams (79 mm by 229 mm deep) at two moisture contents (12 and 28%) and three temperatures (20 °C, 0 °C, and − 40 °C) were tested in four-point bending until failure. Temperature was observed to affect the failure mechanism of the beams, with the beams tested at 0 °C and 20 °C failing in shear and the beams tested at − 40 °C failing in tension. Further, the strengths of the beams and their stiffnesses were observed to increase with decreasing temperature, with these effects being more pronounced in the higher moisture content beams. Over the temperature range of 20 °C to − 40 °C, the 12 percent moisture content beams observed strength and stiffness gains of 17 and 22%, while the 28 percent moisture content beams observed respective gains of 37% and 66%.