Structural Repair of Fire-Damaged Glulam Timber

Abstract

Engineered timber is being used to create increasingly taller structures, with building codes adapting to reflect this drive. While these structures continue to become more common, there has been little investigation into the possibility of repairing fire-damaged timber structural members, leaving practitioners with little guidance in the event of a fire and insurance companies with little information to assess risk. The research herein attempted to repair fire-damaged timber members by removing damaged portions of the timber and replacing them with new timber panels secured with structural screws. Members were loaded in four-point bending, and the findings concluded that the members were able to regain a significant amount of stiffness compared to the control members and on average deflected 19% less than they did prior to repair. The repaired members were not able to reach full strength, however, failing at a load ranging from 49% to 66% of the failure load of the control members. This indicates the need to further examine possible alterations that may improve this repair procedure to the point where composite action is fully enabled and a larger portion of the original strength is recovered. A hypothetical cost analysis based on this repair procedure was provided herein, aiming to help direct several research gaps to be addressed in order to enable the repair of fire-damaged timber.