Flexural behaviour of an innovative cross-laminated timber-concrete composite structural flooring system

Timber-Concrete Composite (TCC) systems are one of the most interesting strategies for slab construction, both for structural performance and environmental considerations. In the latter sense, some research proposed the use of recycled aggregates and locally sourced timber, as well as the reduction of adhesive consumption. This paper analyses the performance of a TCC system in which the timber-concrete connection is achieved by drilling holes in the web, the concrete contains 20% recycled aggregates, and Cross-Laminated Timber (CLT) made from locally source timber is used. Four-point bending tests were developed with a span of 6 m and a height to span ratio of 1/20. In addition, 3D FEM models were calibrated with the experimental results, and used for a better understanding of the failure modes. The samples showed a strength between 4.22 and 4.83 times that required for loads of public use. Furthermore, in service situation they showed a stiffness that amply satisfies the usual regulatory requirements, with deflections between 1/664 and 1/770 of the span. In addition, the ultimate deformation was found to be approximately 6.4 times the service deformation, suggesting sufficient ductility for use in building structures. • A new timber-concrete composite floor has been subjected to 4-point bending test. • The floor structure has been manufactured using CLT made from locally sourced timber. • Concrete containing 20%-recycled aggregates has been used. • The timber-concrete connection has been achieved by drilling holes in the CLT rib. • The system offers adequate strength and stiffness for both residential and public use.