New prestressed concrete design allows for longer, stronger bridges.
The article discusses a new method called Incremental Prestressing of Concrete (IPC) Girders, which allows for longer bridge spans and stronger structures. By using a combination of bonded and unbonded tendons, the girders are pre-tensioned before the deck slab is cast, and then post-tensioned after. This method results in girders with increased live load capacity and the ability to use shallower sections. Tests on full-scale specimens showed that IPC girders have about 30% higher ultimate strength compared to traditional prestressed concrete girders, making them safer and more durable for longer span bridges.