This Ph.D. thesis represents a summative report detailing research processes and outcomes from investigating the ultimate and serviceability limit state short- and long-term behaviour and design of timber-concrete composite floors. The project enables the realization of a semi-prefabricated LVL-concrete composite floor system of up to 15 m long using 3 types of connection. Design span tables which satisfy the ultimate and serviceability limit state short- and long-term verifications for this system form the novel contribution of this thesis.

In quantifying the behaviour of timber-concrete composite floors, 5 different experimental phases have been carried. 9 major achievements in meeting 9 sub-objectives have been concluded:

1. Three best types of connection system for timber-concrete composite floors have been identified;
2. The characteristic strength and secant slip moduli for these connections have been determined;
3. The short-term behaviour of the selected connections defined by their pre- and post-peak responses under collapse load has been established;
4. An analytical model for the strength evaluation of the selected connections based on the different possible modes of failure has been derived;
5. Easy and fast erected semi-prefabricated timber-concrete composite floor has been proposed;
6. The short-term ultimate and serviceability limit state behaviour of timber-concrete composite floor beams under collapse load has been investigated;
7. The long-term behaviour of chosen connections defined by their creep coefficient has been determined;
8. The long-term behaviour of timber-concrete composite floor beams under sustained load at serviceability limit state condition has been investigated; and
9. Design example and span tables for semi-prefabricated timber-concrete composite floors that satisfy both the ultimate and serviceability limit state in the short- and long-term using the gamma-method have been developed.