New analysis: Weathering steel is cost-efficient

It is more cost-efficient to build a composite bridge using weathering steel than painted carbon steel, in terms of both investment and maintenance. This is revealed by a life cycle analysis commissioned by the Swedish Transport Administration. “This supports the arguments in favor of building in weathering steel,” says Fredrik Lindqvist at SSAB.

Pedestrian and bicycle bridge

New pedestrian and cycle bridge the over Soutokoski watercourse

The road between Avvakko and Lappeasuando, which winds its way between Gällivare and Kiruna, is both narrow and of a poor standard. To improve road safety and increase accessibility, the E10 section will be made into a type 3 dual carriageway (2+1 road) with a center divide and a wildlife fence.

On the western side of the road, a new pedestrian and cycle bridge will also be built over the Soutokoski watercourse. To identify the right kind of steel for the bridge, SWECO conducted a life cycle analysis for the Swedish Transport Administration. 

“The analysis involved comparing the costs of investment, inspection, maintenance and repainting for a composite bridge built using weathering steel with those for a composite bridge built using painted carbon steel,” explains Fredrik Lindqvist. 

Weathering steel more cost-efficient  

The results show that weathering steel is the most cost-efficient alternative, in terms of both the investment and maintenance over time. 

“Not having to paint the bridge makes a big difference. That’s a major saving on maintenance costs,” says Fredrik Lindqvist.

The analysis shows that the total cost (both the investment and future costs) of the composite bridge is about 25% cheaper over a period of 80 years compared with a painted bridge made of carbon steel. 

“This analysis supports the arguments in favor of SSAB Weathering being a superb material for building bridges. The low maintenance requirements also mean a lower carbon footprint compared with painted carbon steel,” says Fredrik Lindqvist. 

Construction work on upgrading the E10 road in Gällivare Municipality and the new composite bridge will start in the fall of 2024, and the whole project should complete by the fall of 2027. 

Benefits of SSAB Weathering

The unique feature of SSAB Weathering and weather-resistant steels is the formation of a protective, rust-like coating on the steel surface, a patina that protects against the elements. The material has a long useful life and requires minimal maintenance. An additional benefit of building a bridge in weathering steel is avoidance of the extensive work involved in covering the bridge, taking care of paint residues and possibly diverting traffic during the actual repainting process.

 
Rusted weathering steel

“This analysis supports the arguments in favor of SSAB Weathering being a superb material for building bridges.”

Fredrik Lindqvist, SSAB

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