Ultimate limit state load test of stress-laminated-timber deck

Paper in proceeding, 2010

Glulam beams made of Norway spruce are stressed together with high strength steel bars creating a Stress laminated timber deck (SLTD). Deflections and stresses can be estimated with both finite element models based on orthotropic plate theory as well as with simplified hand calculation methods based simple beam theory. If SLTDs are loaded until failure in the ultimate limit state (ULS), phenomena which generally do not occur in serviceability limit state (SLS) must be taken into account. Slip will occur in the interlaminar surface between the stressed glulam laminations. Once slip has occurred, stress will redistribute between the laminations. A rectangular SLTD was tested for several load levels and pre-stress levels. Deflections were compared with a finite element orthotropic model. These results were also compared with several established design methods. After failure occurred in the ULS, the load was first removed and then applied again, in order to emphasize the reliability of stress redistribution within SLTD.