An analysis of the stress–strain state of a timber–concrete T cross section

The present paper analyzes a stress–strain state of a composite timber–concrete T cross section under a short-term pure bending. The behaviour of a bending moment in respect of a curvature of the cross section was investigated as well. It is assumed that the plane section hypothesis is valid and layers do not slip with respect to each other. The parabolic stress–strain diagram with a descending branch, according to MC90, was applied to the compression concrete while a linear elastic relationship was applied to the timber. The stress–strain state of the cross section was investigated from the beginning of the loading up to the stage exceeding ultimate limit state. The analysis was conducted by applying control of the curvature of the considered cross section. The influence of the tension fibre-reinforced polymer (FRP) and compression steel reinforcements on the stress–strain state of the cross section was also considered. The obtained analytical equations of the layered members were solved numerically. It was found out that the bearing capacity of the cross section is restricted mainly due to low strength of the timber and the tension reinforcement is more effective than the compression reinforcement.