A study on force equilibrium method to determine the effect of slenderness on composite slab with profiled steel decking

Abstract

Numerous researches have confirmed that longitudinal shear failure is the most critical

mode of rupture for composite slabs with profiled steel decking. To assess the horizontal

shear capacity between the concrete and steel sheeting interface, Eurocode 4 recommended

two methods for experimental analysis – m-k and partial interaction method. However, due

to their limitations, a new evaluated and modeled method proposed by Abdullah and

Easterling is adopted in this study. The technique, known as force equilibrium method,

addresses the relationship between the longitudinal shear bond strength and slab

slenderness. The latter was found to be an influential factor to the former in their earlier

studies.

Full-scaled experiment will be carried out in accordance to the standard test procedure

suggested by Eurcode 4 Section B.3. A total of eight composite slab specimens will be

tested – four of them are long spans (4 m x 1 m x 0.11 m) while the remaining are short

spans (2.6 m x 1 m x 0.11 m).

To illustrate the impact of slab slenderness on horizontal shear strength, the experimental

results obtained by Mok and Tay are combined with the present findings. Both experiments

were carried out on composite slabs with similar materials, set-up and environmental

conditions.

The study has concluded that shear bond-end slip relationship varies for different

slenderness. A slender slab exhibits lower longitudinal shear resistance but higher

resistance against concrete-steel deck slippage. The usability of force equilibrium method is

justified by its comparable results with the ones obtained by well-established partial

interaction and m-k methods. Lastly, the procedure is suitable for the use of composite

slabs with trapezoidal or re-entrant profiled decking, and any concrete grade.