Description
Ultra High Performance Concrete (UHPC) is widely used nowadays with the aim to obtain more resilient and sustainable structures. In particular, interest is rising on the use of UHPC for replacing existing slabs in steel-concrete bridge decks, which generally leads to a possible reduction in thickness and, consequently, results in a lower material demand.
As the possibility of substituting existing slabs with UHPC ones is strictly related to the effectiveness of beam-to-slab connection, nine push-out tests have been carried out at the Structural Engineering Testing Hall (Str.Eng.T.H.) of the University of Salerno with the aim to characterize the mechanical behaviour of the shear connection between concrete slab and steel joist. Three groups of specimens were realized, each of which characterized by a slab made of a different concrete and with different thickness. More specifically, i) a 150-mm-thick slab conventional RC slab, ii) a 120-mm-thick medium-strength RC slab and iii) a 75-mm-thick unreinforced UHPC slab were considered for the push-out specimens tested as part of this study. However, Nelson-type headed stud shear connectors, 16 mm in diameter and 64 mm in height, were employed in all those specimens.
This paper reports the results of the push-out tests and compares the different force-slip curves obtained for the three groups of tested steel-concrete stubs, in view of future developments intended at understanding their influence of global behaviour of steel-concrete composite bridge decks.
