Comparison of Calculation Methods of Elastic Bonding: Limits of the Gamma Method Using an Example of a Wood–Concrete Composite Floor with Single Loads

Abstract

Various methods are available for the calculation of timber–concrete composite floors. The gamma method, which is important in construction practice, as well as the differential equation method, are based on the simplified assumption of a continuous bond between wood and concrete. This makes it possible to analytically calculate the internally statically indeterminate partial section sizes and deformation sizes, analogous to the force size method. In this paper, two typical load situations of concentrated loads (central and off-centre) were analytically and numerically evaluated and compared using the above-mentioned methods (gamma and differential equation), with a discrete method for the case of a timber beam reinforced with a concrete slab using screws as fasteners. The calculation results show significant deviations, which speak for the application of discrete methods in certain load situations and thus limit the usability of the gamma method under certain conditions. For the problem of deflection determination, which is not dealt with in the literature for the discrete method, a numerical method is described in the present work, which was first developed and presented by the first author.

Screw Connection Systems in Timber-Concrete Composite Structures: A Literature Review

“…In the finite element analysis done by Huber and Deix [55], the gamma method has been concluded as a modelrate unprecise method for the computational determination of timber-concrete interaction with common design features, especially for predominantly eccentrically located load situations compared to the more stringent method.…”

Cost Factor Analysis for Timber–Concrete Composite with a Lightweight Plywood Rib Floor Panel

“…There are two typical TCC solutions-a concrete layer with cross-laminated timber (CLT) panel and a concrete layer with timber beams [28]. The TCC with timber beams is usually used with a thick reinforced concrete layer to provide sufficient bending stiffness.…”