Experimental fire testing of damaged glulam beam connections retrofitted using self-tapping screws

Abstract

During the lifespan of timber buildings, structural members may exhibit different defects and/or failures. This may include splits that develop due to shrinkage because of changes in the moisture content of wood and/or due to excessive flexure bending, tensile, or shear stresses. To rehabilitate timber structures, there are various retrofitting techniques used to strengthen damaged wood members. Some of the available methods include the utilization of fiber-reinforced polymer wrapping sheets, mechanical fasteners such as self-tapping screws (STS), and glued-in rods. The utilization of STS was proven to be the most economical and easiest retrofitting technique. In

ambient conditions, this technique has been shown to greatly increase the strength of wood-steel- wood (WSW) connections when subjected to flexure bending. STS have also been shown to

significantly increase the ductility of timber beams utilizing such reinforced connections. Although STS have proved to be very effective in enhancing the strength of glued-laminated timber (glulam) beams with WSW connections in ambient conditions, there has been very minimal research on the effect of STS on retrofitting glulam beams with such connections in fire conditions. [...]