Critical Discussion on the Performance of Underslung Movable Scaffolding Systems Strengthened With an Active Prestressing System

Abstract

The use of Movable Scaffolding Systems (MSSs) has proven to be an efficient and competitive construction method for in-situ prestressed concrete bridge decks. Among them, underslung MSSs are commonly used for spans up to 60 m, but the integration of active external prestressing systems has recently enabled their application to spans of up to 70 m. However, the effectiveness of these active systems is highly dependent on several design situations, and their benefits are not uniformly applicable across all construction stages. This paper examines the design optimization of MSSs with and without active prestressing system, evaluating their structural and economic implications. A detailed comparison is provided to assess the practical advantages and limitations of active prestressing systems, considering key influencing factors such as the construction sequence and operational constraints. Finally, the paper offers insights into the advantages and drawbacks of these systems in various bridge construction contexts.