Hofplein Railway Viaduct (1900-1908): A Pioneering Concrete Structure that Challenges Conservation

The Hofplein railway viaduct (1900-1908) in Rotterdam was once the longest Dutch reinforced concrete structure. Its underlying design is remarkable for its period, as alternatives to then common patented reinforcement systems were sought. Experience with reinforced concrete was still limited. During construction, the design was adapted, leading to a variety of reinforcement systems. Special attention was given to the surface finish, using a combination of natural stone plinth and a tooled artificial sandstone render. The structure is listed as a national monument. Degradation is present, affecting the unique reinforcement and surface finish. Being a monument, additional conceptual conservation requirements would have to be fulfilled during an intervention. In this paper, the relationship between the heritage values, historic fabric, and state of conservation is explored, and the resulting case specific criteria for a possible conservation.