ANALYSIS OF EXPERIMENTAL RESULTS ON A CHEMICAL-MECHANICAL CONNECTION IN TIMBER CONCRETE COMPOSITE FLOORS

A new type of connection is presented for timber to concrete composite structures, using new glued laminated timber beams. The connection comprises a particular milling to create back-to-back L-shaped longitudinal grooves within the top side of the glulam joist with a number of wood tenons, and the concrete slab. The connection is prepared by using also a high resistance anti-shrink cement mortar which bonds to the timber (giving the chemical connection), with steel reinforcing bar trusses anchored in the mortar and protruding into the concrete to give the mechanical connection. The efficacy and validity of the system are demonstrated by a comprehensive experimental and numerical investigation, which allowed also the determination of the stiffness of the composite beam and its load carrying capacity. The research has been carried out in two phases; initially, several solutions have been studied, while in the second phase the most interesting one has been analysed in detail and optimized. An accurate numerical model has also been implemented with the aim of correctly predicting the mechanical behaviour of this particular type of connection to be used for new timber-concrete composite structures.