Cast-in-Place Deck Placement Sequence

The cast-in-place deck placement sequence considered by the bridge designer must be provided in the contract plans, and must be taken into account as part of the girder constructibility checks. Common practice when placing the deck in continuous span bridges is to place the cast-in-place deck slab in the positive moment regions first and then place the cast-in-place deck slab in the negative moment regions over the supports. A strategy such as this is typically adopted in order to minimize the potential for cracking at the top of the deck slab in regions that are subjected to negative moment. It should be noted that when concrete is placed in a span adjacent to a span that already has a hardened concrete deck, negative moments in the span with the hardened concrete will often result. These negative moments will cause tensile stresses in the hardened concrete that could result in transverse deck cracking. The concrete deck stresses during deck placement should be checked in accordance with Article 6.10.3.2.4 of the AASHTO LRFD (7th Edition, 2014).