Repair and upgrade of a trough structure using ultra-high-performance fiber-reinforced concrete (UHPFRC)
Ultra-high-performance fiber-reinforced concrete is a purely mineral concrete matrix mixed with steel fibers. In Switzerland, it is one of the standardized, widely used building materials. Based on the Swiss SIA 2052 standard, Implenia has successfully repaired and rehabilitated more than a dozen infrastructures in Switzerland since 2018, as well as initial projects in Germany, to preserve them for a long time. Also acting as a waterproof seal and protective layer, UHPFRC provides a cost-effective solution for maintaining existing infrastructures by repairing road surfaces including gradient leveling, as well as bridge perimeters. On the positive side, using UHPFRC thus results in reduced material consumption dramatically shorter construction times while allowing for project execution almost throughout the year.
The above benefits prompted the municipality of Nackenheim in the German State of Rhineland-Palatinate to opt for UHPFRC rehabilitation of a reinforced concrete trough structure originally built in 1976. This 115 m long underpass connects the southern and northern parts of the town and passes underneath a railway line. As part of the reconstruction of the traffic route, extensive concrete repair is performed to subsequently rebuild carriageways, pedestrian and cycle paths, and vertical sections of the trough walls by placing over 160 m³ of a UHPFRC of class UA conforming to the Swiss SIA standard.
Prior to the public invitation to tender, a renowned engineering firm conducted an independent study of possible repair options, which found that, for this structure, repair and rehabilitation with UHPFRC was an efficient, durable, and cost-effective alternative to conventional repair and installation of an asphalt road pavement.
