Biaxial timber‐concrete composite slabs made of beech laminated veneer lumber

Summary

In the past years, the search for an efficient and economical timber slab system has led to great interest in timber-concrete composite (TCC) structures. TCC slabs consist of wooden elements such as beams or plates, an overlying concrete slab and a shear-resisting connection in between. Compared to pure timber slabs, these structures provide not only significantly higher load-bearing capacity and stiffness, but also show a much better behaviour regarding dynamics, acoustic insulation and fire resistance. Meanwhile, compared to classical reinforced concrete slabs, the demand for steel and concrete can be reduced, providing a more sustainable solution. The timber elements have a double function both as concrete reinforcement and as formwork, offering the potential for very economical construction processes.

A TCC slab made of beech laminated veneer lumber has been developed and studied at IBK by Lorenzo Boccadoro during the past years (link). The present project focuses on extending the applications of this system, with the long-term goal of providing a viable TCC alternative to reinforced concrete flat slabs. In order to achieve this goal, the following problems have to be solved:

• Achieving a biaxial bearing behaviour of the slab (2-way spanning slab)
• Adding the possibility of point supports (columns instead of walls or girders)
• Increasing the stiffness of the timber elements during the construction state in order to reduce the need for propping

Support

This project is carried out in collaboration with Implenia AG and WaltGalmarini AG and is kindly supported by Innosuisse, the Swiss Innovation Agency.