Timber-Concrete Composite Floor Beams under 4 Years Long-Term Load

The long-term behaviour of timber-concrete composite is characterized by the response of its three components (timber, concrete and connection) to load, moisture content, temperature and relative humidity of the environment. This paper reports results of a 4-years long-term test on three 8m span laminated veneer lumber (LVL)-concrete composite floor beams under service load performed in an indoor, uncontrolled, and unheated environment at the University of Canterbury. The environmental conditions were characterized by either low temperature with high relative humidity or high temperature with low relative humidity, conditions considered to be reasonably severe and presumably close to service class 3 according to Eurocode 5. The mid-span deflections were extrapolated to the end of service life (50 years) and compared to span/200 deflection limit, which was exceeded by all beams.