Experimental and numerical analysis of a full-scale timber-concrete-composite beam from simply supported to frame-connected

TL;DR

This study combines experimental and numerical methods to analyze full-scale timber-concrete composite beams, revealing significant deflection reduction and stress redistribution in frame-connected configurations, and proposes a new design criterion.

Contribution

It provides the first comprehensive comparison of simply supported and frame-connected TCC beams at full scale, including a validated finite element model and a new dimensioning criterion.

Findings

Frame-connected beams exhibit less than 50% deflection of simply supported beams.

Numerical model accurately predicts behavior and allows stress reduction up to 49%.

Proposes a practical dimensioning criterion for frame-connected TCC beams.

Abstract

Numerous TCC (timber-concrete composite) systems have been proposed and studied in recent years. Most of the studies have focused on the behaviour of the timber-concrete shear connection and the flexural behaviour of floor elements. This paper presents the results of an experimental and numerical study comparing the behaviour of a simply support beam and a beam connected in continuity to mixed TCC supports (a frame-connected beam). Full-scale tests were carried out with 370 mm wide beams and 5.9 m span. Experimental results have shown that the deflection in the frame-connected beam was less than 50% of those observed in the simply supported beam. A three-dimensional finite element model has been validated and calibrated from the test results. This model has been used to evaluate the moment redistribution in the frame-connected beam which, in the case studied, allows the maximum stresses in the timber members to be reduced by up to 49%. Based on the numerical and experimental results, a dimensioning criterion is proposed for the frame-connected beams.