Fire Resistance of Epoxy-grouted Steel Rod Connections in Laminated Veneer Lumber (LVL)

Abstract

Epoxy-grouted steel rods are becoming increasingly popular for connections in structural timber in glue-laminated timber (glulam) and laminated veneer lumber (LVL). This research focuses on the fire resistance of these connections in LVL timber. These connections have been found to have high strength under service temperatures, but epoxy is known to soften at relatively low temperatures. To determine connection performance, an experimental investigation was carried out on the axial tensile strength of connections that utilised a threaded steel rod bonded into the timber using two epoxy resins and a composite adhesive. Some specimens were tested at constant elevated temperatures while similar specimens were tested in simulated fire conditions under constant load. The three adhesives tested gave different connection strengths at ambient temperatures and showed different strength losses at elevated temperatures.