Precast, prestressed hollow-core slabs are usually used as part of a simple span system. However, in a multispan floor slab system, designing for continuity over supports leads to increased span capacity, improved structural integrity and savings in materials. In this paper, formulas relating the fractional increase in span capacity, percentage of moment redistribution from supports and design midspan and support moments of hollow-core slabs are derived theoretically. These relations are put in a graphical form to facilitate the design of connections in continuous hollow-core slabs, the use of which is illustrated by several examples. To demonstrate the development of full continuity at the supports, three specimens, each consisting of two hollow-core slab components on a supporting beam element and connected by in-situ structural concrete topping, were tested under three-point loading to simulate the portion of a continuous span under hogging bending. The test results show that the specimens did achieve the ultimate load-carrying capacities calculated using conventional reinforced concrete theory. Under heavy shear conditions, vertical links placed in the cut-open cores were found to be effective in improving the shear behavior of the specimens.
