The maintenance and consolidation of railway infrastructures are strategic priority interventions to guarantee the safety of the network and continuity of service. The conservative rehabilitation of three railway bridges along the RFI Paola-Acquappesa-Bonifati line, in the province of Cosenza, designed and directed by RFI – Rete Ferroviaria Italiana and carried out by the company GBL Costruzioni Srl, is part of this context.
The types of intervention
The intervention involved three works of different types: a two-span bridge in the municipality of Paola, a three-span bridge in the Acquappesa area and a railway pedestrian walkway in Bonifati, all sharing the need to reinforce the main reinforced concrete beams while maintaining the infrastructure in operation and limiting operating times to a minimum.
To meet these needs, the project identified Laterlite systems – and in particular the Ruregold brand FRCM solutions – as the most effective response for the structural reinforcement of beams. After the preliminary operations of restoring the concrete covers using thixotropic mortars, the consolidation was carried out with the system composed of PBO-MESH 105 and MX-PBO Calcestruzzo, a technology designed to increase the resistant capacity of the reinforced concrete elements while ensuring high durability and compatibility with the existing support.
PBO-MESH 105 and MX-PBO Concrete
PBO-MESH 105 is the bidirectional PBO fiber mesh with high mechanical performance, designed for the reinforcement of beams, pillars, structural nodes and reinforced concrete structures. The high tensile strength, combined with the extremely low weight, allows the load-bearing capacity of the elements to be increased without adding significant additional loads, improving their behavior towards static and dynamic stresses.
To ensure the collaboration between the concrete support and the mesh is MX-PBO Calcestruzzo, a cement-based fibre-reinforced inorganic matrix developed for Ruregold FRCM systems. The mortar guarantees an effective transfer of tension between the product and the PBO mesh, ensuring high mechanical performance and long durability even in particularly aggressive environments such as coastal ones.
Construction site and safety
The choice of Ruregold systems was dictated not only by the high mechanical performance necessary to restore the original safety levels of the structures, but also by the important organizational implications on the construction site. After the restoration of the degraded parts, it was in fact possible to proceed quickly with the reinforcement without having to wait for the long maturation times required by other technologies, optimizing the sequence of processes and reducing the overall times of the intervention: a particularly relevant aspect in a railway project, where speed of execution represents a determining factor in limiting the impact on operating activities.
The intervention confirms one of the main strengths of Ruregold FRCM systems: the ability to combine high structural performance, reduced thicknesses and simplicity of application, offering an effective solution for the consolidation of existing infrastructures without altering their geometries and functionality. The lightness of the system, the resistance to corrosion and the durability over time also make it particularly suitable for works located in highly environmentally aggressive environments, as in the case of the Tyrrhenian coast of Calabria.
For further information
laterlite.it
ruregold.com
