High Strength Steel S690 in highway bridges

Abstract

The use of High Strength Steel (HSS) S690 in highway bridge decks is not yet widespread. A research program investigated the optimal use of HSS in bridges. A comparative design was performed for a 21.5 m wide highway bridge, with a typical 80 m long inner span and a steel-concrete composite twin plate girder deck, using the Eurocode standards. Three designs were produced: Design (A) with S355 NL steel grade, Design (B) with HSS S690 QL/QL1, and Design (C), also with HSS S690, but exploring different design options provided by welded joint treatments to improve fatigue and suggest possible enhancement of the present Eurocode rules. General guidelines for the design of highway bridge decks using HSS S690 are provided. Keywords: bridges; steel-concrete composite deck; high strength steel; plate buckling; fatigue Hochfester Stahl S690 für Autobahnbrücken -Allgemeine Hinweise für die Bemessung und Konstruktion. Die Verwendung von hochfestem Stahl (HFS) S690 für Autobahnbrücken ist noch nicht weit verbreitet. Ein Forschungsprogramm hat die optimale Verwendung von HFS für Brücken untersucht. Für eine 21,5 m breite Autobahnbrücke mit einer typischen inneren Stützweite von 80 m und einem Stahlbetonüberbau mit zwei Plattenträgern wurde ein Konstruktionsvergleich nach Eurocode erstellt. Es wurden drei Entwürfe Stichworte: Brücken; Stahlbetonüberbau; hochfester Stahl; Blechbeulen; Ermüdung ULS bridge deck design 2.1 Bending resistanceThe flange widths and thickness of the main plate girders were first defined to achieve the required bending resistance. The span flanges were then re-assessed based on fatigue requirements. The final geometry of the main girders is presented in Figures 2 to 7, for standard steel S355 and HSS S690.Differing from the Class 3 sections usually adopted in the design of support sections, when using HSS the bottom flange and web at support sections are Class 4, due to the compact thickness required and the very low value of

Lifecycle cost assessment of high strength carbon and stainless steel girder bridges

“…The beneficial effect of higher strength steel grade was combined with low maintenance costs, and the duplex option turns out to have a lower lifecycle cost (LCC). Very similar observations were made in (Habraken et al, 2019;Lemma et al, 2020;Pedro et al, 2018Pedro et al, , 2017 where the possible weight reduction when S690 is used instead of S355 in a steel girder bridge is calculated. The weight reduction of structures via the use of higher strength materials is reported in many other studies (Budano et al, 2007;Günther, 2005;Lagerqvist et al, 2007;Sedlacek et al, 2002;Shi et al, 2014) but, to the authors' best knowledge, most of these studies did not consider fabrication/maintenance costs.…”

“…• Creep and Shrinkage effects are considered in the material model of concrete following the information given in (Habraken et al, 2019;Pedro et al, 2018Pedro et al, , 2017 where single stage casting is considered.…”

“…Cross girders are connected to the T-stiffeners of the web at a distance of each 8 meters. As given in (Habraken et al, 2019;Pedro et al, 2018Pedro et al, , 2017, for the S355 bridge, T-stiffeners were used every 8 m through the entire span. Besides, flat stiffeners every 2 m are considered over a portion of 24 m from the supports and then spacing increases to 4 m for the rest of the span.…”

“…The higher strength steels considered in this study are the S460 structural carbon steel grade according to (EN 10025-3, 2019) and the duplex stainless steel EN 1.4162 according to (EN 10088-2, 2014). The case study proposed by (Pedro et al, 2018(Pedro et al, , 2017 is presently chosen as the reference bridge. In the current paper, the bridge is assumed to be located in a coastal area in Belgium where the needed Corrosion Resistance Class (CRC) is considered to be 3 with the following points taken into account according to (DMSSS, 2017;EN 1993EN -1-4 A1, 2015):…”

“…The reference design (Habraken et al, 2019;Pedro et al, 2018Pedro et al, , 2017 compares two design options made of S355 and S690. The comparative design studies the midspan of a highway girder bridge (80 m) with 5 spans with a total length of 360 m (Span CD in Fig.…”