Time-dependent behaviour of timber-concrete composite members: Numerical verification, sensitivity and influence of material properties

This paper presents a study that models timber and concrete material properties in order to understand their influence on the structural response of timber-concrete composite (TCC) beams under long-term loads. First, the accuracy of a 1D composite frame (finite element) FE model developed by the authors is verified against available short- and long-term experimental data, which included characterising the material properties. Using the developed formulation and analytical tools, comprehensive sensitivity analyses and parametric studies are conducted to gain better understanding about time and moisture dependant factors that affect long-term behaviour of timber and timber-concrete composite beams. With regard to the results of parametric studies, the required input parameters (not available yet) for long-term analysis of laminated veneer lumber (LVL) are suggested. It is shown that the proposed simple strategy can adequately and efficiently capture the short- and long-term material behaviour of timber, TCC and timber-timber composite (TTC) structures and can be employed for design oriented parametric studies.