CEMEX help restore historic Augustus Bridge
CEMEX Germany develop bespoke concrete solution to renovate 289-year-old river crossing in Dresden
CEMEX Germany are producing an innovative and customized light-coloured ready-mixed concrete to restore the 289-year-old Augustus Bridge over the river Elbe in Dresden, Germany.
The current iteration of the bridge was built around 1730 but underwent renovation between 1907 and 1910 when it was redesigned as a series of three-hinged concrete arches. The visible surfaces of the nine arches and eight piers were clad in sandstone, with tamped concrete forming the core of the bridge.
In addition to fulfilling historical standards by preserving the colour and surface texture of the bridge’s original material, the new bespoke concrete is designed to ensure the bridge’s structural integrity as well as comply with the visual consistency of the other historical pieces of architecture and infrastructure in the region.
The project’s primary contractors, Hentschke Bau GmbH, are using approximately 4,000 cubic meters of concrete from CEMEX Germany. Concreting work began in April 2017 and is expected to be completed by the Spring of 2020.
The renovation includes the total replacement of one of the bridge’s arches at the Old Town abutment above the Terrassenufer riverside road. Each of the bridge’s arches and piers will be equipped with reinforced concrete slabs as a basis for a new waterproofing system. In addition, all visible surfaces made of sandstone will be extensively repaired.
In order to maintain the historical integrity of the bridge, CEMEX Germany developed a bespoke, light-coloured concrete that matches exactly the original colour and style of the bridge.
Created by CEMEX’s ready-mix technologists, the customized concrete is being used for both the new construction of the arch at the Old Town abutment as well as the restoration and reinforcement of all the other arches and piers.
The customized colour was developed by mixing yellow and red pigments with limestone chippings, limestone powder, and a special binder that ensures the required strength of the bridge with the added feature of reduced heat generation, which is critical in historical restorations.
‘The greatest challenge in terms of concrete technology is the restoration of the arch over the Terrassenufer, since the concrete for that section must have the same appearance as the historic concrete from 1910,’ explained CEMEX Germany area manager Uwe Engelhardt. ‘The construction site is particularly challenging due to its unique location against the backdrop of Dresden’s historic Old Town, with the bridge as a central location in the city.’
The Augustus Bridge spans the river Elbe between the old and new towns of Dresden, at a point on the river where there has been a crossing since the 12th century. At 561m, it was the longest stone arch bridge in Europe at the time it was constructed.