Analysis of Performance of Local Puzzle Sheet in a Joint Made of UHPC

Nowadays the extraordinary mechanical properties of UHPC can be used for real structures. The exceptionally high bond of reinforcement and UHPC together with significant shortening of lap length are the key features for the simplification of joining of precast elements. The properties of UHPC can be very well used also for providing of subsequent shear connection of composite structures. This paper is focused on analysis of performance of a combined joint where connection of precast elements as well as subsequent composite action between steel and concrete parts of steel-concrete composite structure are carried out in one compact detail. Instead of the traditional headed shear studs there were used local perforated puzzle sheets. More resilient connection of shear sheets to the top flange and a high resistance of UHPC allow for reduction of the extent of shear connectors. In experimental measurements carried out on six beams the behavior of shear connection of conventional monolithic concrete slab with continuous perforated shear sheet and shear connection of precast slab with the joint made of UHPC with local puzzle sheets were compared. During the experiment it has been proven that the performance of the beams with both variants of shear connection is very similar even with the significant reduction of the extent of shear connectors. Numerical analysis which describes the stressing in this detail confirms such behavior.