The aim of this document is to report the state of the art in terms of research and practice of Timber-Concrete Composite (TCC) systems, in order to summarize the existing knowledge in the single countries and to develop a common understanding of the design of TCC.
This report was made within the framework of WG4-Hybrid Structures within COST Action FP1402. It intends to reflect the information and studies available around the world, but especially in Europe through the active contribution and participation of experts from various countries involved in this Action.
Timber-concrete composite (TCC) solutions are not a novelty. They were scientifically referred to at the beginning of the 20th century and they have proven their value in recent decades. Regarding a TCC floor at the design stage, there are some assumptions, at the standard level, concerning the action of concentrated loads which may be far from reality, specifically those associating the entire load to the beam over which it is applied. This naturally oversizes the beam and affects how the load is distributed transversally, affecting the TCC solution economically and mechanically. Efforts have been made to clarify how concentrated loads are distributed, in the transverse direction, on TCC floors. Real-scale floor specimens were produced and tested subjected to concentrated (point and line) loads. Moreover, a Finite Element (FE)-based model was developed and validated and the results were collected. These results show that the “loaded beam” can receive less than 50% of the concentrated point load (when concerning the inner beams of a medium-span floor, 4.00 m). Aiming at reproducing these findings on the design of these floors, a simplified equation to predict the percentage of load received by each beam as a function of the floor span, the transversal position of the beam, and the thickness of the concrete layer was suggested.
Point and line loads are common load cases in slabs, however their effects on timber-concrete composite (TCC) slabs are not fully known. Hence, the importance of investigating the associated structural behaviour and developing technical design rules. For this purpose, an investigation including experimental tests and theoretical analyses was performed. Five composite real scale specimens were built, each one associated with a different parameter whose effect on the load distribution was intended to be analysed. Each specimen was subjected, at a time, to point and line loads over each beam at different locations. Numerical modelling showed good agreement with experimental results and give way to a parameter study. In general, the beam over which the load was applied received the highest share of load and the distribution for the remaining beams is significantly affected by the span.