Physical and Chemical State of the Concrete Piers of the Former Franz Joseph Bridge Built in 1891

Abstract

This article discusses the properties of concrete within the piers of the Old Bridge in Bratislava (former Franz Joseph Bridge). It was the first permanent bridge across the river Danube in Bratislava as well as within the present territory of Slovakia. Mechanical, physical and chemical properties were verified on core drills, some of them being almost 23 m long. The concretes were tested for dynamic and Young’s elasticity module and compressive strengths. Subsequently the fines of concrete specimens were studied by the X-ray diffraction, TG-DTA and mercury intrusion porosimetry techniques and also by chemical analyses and SEM observations. The piers were made from 5 different concrete kinds. The concrete in the caissons and in the piers does not fulfil the criteria for structural concrete defined in the present European standards. This finding seriously suggests that carrying capacity of the piers after the reconstruction of the bridge, without any strengthening would become questionable.

The Cause of 100-year Low Carbonated Concrete of the Bridge

“…In 2014-2015 in-situ and laboratory tests of 7 old bridges: Bratislava -the year of construction 1891, Hlohovec-1910, Krásno nad Kysucou-1891, Nyiregháza -1885 (presently in Hungary, tests performed in the cooperation of Hungary and Slovakia), Sládkovičovobefore 1920, Ružomberok-1912 and Nižná Myšľabefore 1920, were carried out. The bridge in Sládkovičovo with the found protective render coat (PRC) was firstly tested in 2015 and repeatedly in 2018 [24][25][26][27].…”

“…5) and compressive strength (CP) [33]. Descriptions of the test methods, mainly the procedures applied in Slovak Technical Standards (STN, STN ISO) are reported in a detail in the papers [24][25][26][27]. The cylindrical concrete specimens were half broken in the laboratory by longitudinal splitting.…”