Massive timber floor system evaluated at Clemson University
Research at Clemson University is being conducted on an innovative, hollow massive timber floor system derived from a modification of solid Cross Laminated Timber that will be able to meet the stiffness requirement of longer spans. This floor system consists of two smaller 3-ply solid CLT panels that act as the top and bottom surface (or floor and ceiling) of the hollow panel. These two panels are separated by a glulam beam on an approximate 36″ o.c spacing. All three of these elements have to be connected together in order for them to act as one floor panel that resists out-of-plane bending loads. By making the cross-section deeper and removing extra wood in the middle that does not give much additional strength to the panel, a much more efficient cross-section is made in terms of wood use.
During this past Summer, Clemson researchers developed and ran computer models of the hollow panel in order to learn more about the mechanics of the panel and to determine what influences the strength and stiffness of the floor system the most. A parametric study was done by varying many variables in order to see the effects of geometry of the cross-section, quality of the boards in each layer and the connection method used to connect the two outer panels. It was found that the strength and stiffness of the connector was the most influential value. Therefore, we decided to run shear tests on many different connectors in order to find the best one for our panel.