The potential benefits of using the bridge form of precast prestressed beams supporting in-situ concrete top slab are:
(i) For bridges built on top of rivers and carriageway, this bridge form provides the working platform by the precast beams so that erection of falsework is not required.
(ii) This bridge form generally does not require any transverse beams or diaphragms (except at the location of bridge supports), leading to reduction of construction time and cost.
(iii) It creates the potential for simultaneous construction with several spans.
Ref: A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.