Long-term load test of a wood–concrete composite beam

This paper presents the results of an experimental investigation on the time-dependent behaviour of a layered wood–concrete composite beam specimen with notched shear key interlayer connections, under long-term static load and simultaneous exposure to naturally changing ambient environmental conditions including temperature and relative humidity. A creep test was performed to provide data about the behaviour of the wood–concrete composite beams for the first 5 month duration of the service life, while environmental conditions (relative humidity and temperature) were continuously monitored. A change in relative humidity makes the moisture content inside wood change, and the variations of moisture content in the wood create shrinkage/swelling in the wood layer. This variation also directly affects the mechanical properties of wood as well as causing the mechano-sorptive phenomenon in wood materials. In addition, an interconnected layered wood–concrete beam is an internally indeterminate structure; for example, as the wood and concrete have different thermal expansion coefficients, changing temperature in time creates thermal stress fields within the materials and deflections that vary with time. The test data presented were used to validate a three-dimensional numerical model implemented in the commercial software ABAQUS.