Concrete challenges on the Superway

The $842M South Road Superway project is the biggest single investment in a South Australian road project. It will deliver a 4.8km long non-stop expressway standard corridor from Adelaiders Port River Expressway to Regency Road and is part of a larger programme to upgrade the whole of South Road to a high standard, high speed arterial link. The project features a 2.8km long elevated roadway carrying up to eight lanes of traffic above the existing South Road. The brief for the project required the elevated roadway to have a 12m clearance under the superstructure, minimum spans of 60m, to provide a high standard of landscape and urban design finish, improve safety of road users, limit impact on the adjacent businesses and provide a useable undercroft area during and after construction. Urban Superway JV were awarded the design and construct contract based on an elegant design with curved piers and a match cast segmental balanced cantilever superstructure with spans varying from 60m up to 83m. Key features of the project included integral construction at the pier/deck junction and mid span superstructure articulation using needle beams n a first for Australia. This form of articulation reduced the need for large bearings under the deck and thus reduced future maintenance requirements. The paper will provide an overview of the design and construction of the project focusing on key areas where innovative structural design and concrete technology combined to meet the project requirements for a durable and low maintenance structure. The paper will also discuss how variations in the exposure conditions across the site influenced the design and detailing of the elevated viaduct elements.