Design of Composite Steel-Concrete Bridges using Stainless Steel Girders with Currugated Webs
Typ
Examensarbete för masterexamen
Program
Publicerad
2020
Författare
Henrysson, Adam
Yman, Elly
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Steel-concrete composite bridges that are designed in Sweden today are almost exclusively
conducted in carbon steel. Carbon steel is susceptible to corrosion, a
consequence of which is the need to maintenance, mainly in form of repainting,
surveillance, and other related work, during the service life of the bridge. A reduction
of the maintenance costs is possible by instead utilising stainless steel in design
of the girders. Bridges in stainless steel are nearly maintenance-free and not susceptible
to corrosion. However, manufacturing of bridges using stainless steel is more
costly than carbon steel and therefore, effective material utilization is desirable. In
this regard, beams with corrugated webs are advantageous as larger material utilization
can be achieved. Girders with corrugated webs provide high shear-buckling
capacity, resulting in slenderer web plates. Further, the proof stress of stainless steel
is higher than that for conventional carbon steel that is often used in bridge sector.
The aim of this study has been to evaluate the applicability and effectiveness of
designing composite bridges by replacing carbon steel girders with flat webs, with
stainless steel girders with corrugated webs. Further, the aim has been to highlight
specific parameters that influence the design of such girders, and conclude the study
by showing the possible savings in terms of material usage and cost estimation
that could be achieved by implementing this concept. The latter is carried out by
redesigning two existing composite bridges in a comparable manner to the original
design.
The results of the case studies show that material savings of 20-30% can be achieved
by implementing the suggested concept. Furthermore, if the height of the girders
were allowed to be deeper, a quadratic saving of material could be obtained for
every linear increase in depth. However, there exists an optimum depth from which
no excessive material savings are made by further increasing the height. The study
also shows that girders designed in stainless steel are subjected to larger compressive
stresses due to temperature strains. This is mainly due to the discrepancy of coefficient
of thermal expansion between stainless steel and concrete. Lastly, the cost
estimation analysis shows nearly the same investment costs for the original design,
and the alternative with stainless steel and corrugated webs thanks to the material
savings and less production costs. The cost savings over the service life of the bridge
makes the investigated concept extremely beneficial.
Keywords: Stainless steel, Corrugated web, Material savings, Maintenance costs,
Bridge design, Steel-concrete composite bridges
Beskrivning
Ämne/nyckelord
Stainless steel , Corrugated web , Material savings , Maintenance costs , Bridge design , Steel-concrete composite bridges