Infrastructure, Bridges and Viaducts
Molise II viaduct, also known as “Il Liscione,” is an imposing structure dating back to the 1970s. Due to the deterioration of the concrete elements, increased traffic volumes, environmental conditions, and regulatory updates, the viaduct underwent a redevelopment intervention 50 years after its construction.
This is part of a project by the ANAS Department of Campobasso, which initiated a series of interventions related to the consolidation of viaducts and artworks along the SS 647 “Fondo Valle del Biferno” road. All the planned works are part of the Triennial Framework Agreement for the extraordinary maintenance of viaducts located along the state roads in the Molise Region, including Molise I and Molise II viaducts.
The works for the Molise II viaduct were entrusted to Research – Consorzio Stabile A.R.L., of which Infrastrutture Srl is a part, as the executing company. In compliance with the specifications of the contract, they selected Fibre Net as the supplier, opting for solutions designed to withstand specific environments, easy and quick to install, and with guaranteed long-term performance.
Focus on solutions and interventions
High-performance products were used for the consolidation and waterproofing of the slabs, replacement of metal barriers, as well as the installation of technological systems for collecting, diverting, and treating polluted liquids on the Molise II viaduct.
For the Molise II viaduct, products from Fibre Net’s Structure, Integra, and Acqua technical lines were chosen for large-scale projects. These products meet the requirements of major road and railway operators for restoration and upgrading of reinforced concrete and pre-stressed conglomerate structural elements, as well as masonry works.
They are widely used for maintenance, improvement, and consolidation of electrical infrastructure, water management systems, as well as port and logistics facilities.
The process began with milling the asphalt pavement, followed by the demolition of the reinforced concrete curb, and then the hydrodemolition of the reinforced concrete slab using a special milling machine that precisely removed the concrete layer with a high-pressure water jet. Once all the scarified parts were removed, mechanized suction was used to collect the debris.
The next phase involved drilling the slab, applying new reinforcements, and treating the existing reinforcements with the application of a cementitious mortar, Integra Ferro – FR718, in accordance with the European Standard EN 1504-7. This mortar has excellent adhesion to metal reinforcements and is suitable for passivating iron subject to corrosion.
The slab was then poured after applying a special acrylic-based adhesion promoter, Integra Special – LT734, which consolidates and improves the bond between the existing substrate and the new structural repair concrete.
Next, a medium-thickness layer of 8 cm of Struttura Fluido – FL475 was poured. This is a pre-mixed, fluid, fiber-reinforced cementitious mortar, air-entrained, complying with the European Standard EN 1504-3 for Class R4 structural mortars of type CC. It has high adhesion to the substrate, dimensional stability, resistance to weathering and freeze-thaw cycles, and high mechanical strength even at early stages of curing, allowing reliable and rapidly operational structural repairs.
A liquid curing additive, Integra Special – SRA513, with a very low chloride content, was added to the mixer truck to reduce shrinkage and promote curing of the concrete.
After the structural concrete was placed, the pours were covered with non-woven fabric sheets and wetted with water to prevent cracking due to shrinkage, ensuring optimal curing of the concrete.
The subsequent operations involved the placement of the reinforcements for the curb, the installation of formwork, and the pouring of structural concrete. Prior to the installation of the new protective barriers on the reinforced concrete curb, a mortar called Acqua Scudo CEM – SC601 was applied. This pre-mixed, two-component, thixotropic, and waterproof cementitious mortar complies with the European Standard EN 1504-2, following the principles of PI (penetration protection), MC (moisture control), CR (chemical resistance), and IR (increased resistivity).
The next step was the pouring of the joints using reoplastc concrete with controlled shrinkage, packaged with Integra Lego – LP159, an expansive super-fluid binder and aggregates with the appropriate particle size distribution.
The technical laboratory of the Fibre Net Study Center conducted and documented mixture tests in accordance with ANAS regulations and the requirements of Infrastrutture Srl. All the reports and the mix design were made available to carry out the necessary pre-qualifications and subsequent installation. Finally, the new barriers were installed, the new slab was waterproofed, and the wearing course was applied.
The added value of Fibre Net
In the context of rehabilitation, restoration, structural reinforcement, consolidation, and improvement of existing infrastructure assets, the company is capable of assisting and supporting institutions, designers, and construction companies in making the most appropriate and effective choices aimed at ensuring the durability of the assets.
Fibre Net’s Infrastructure Division not only focuses on product development but also provides additional services to enhance and streamline the work process, both during the training phase and on-site assistance, assisting the construction company in material preparation and installation operations.
Founded as a company to produce composites for building, today FIBRE NET offers specialised engineering services and assistance to the entire construction industry supply chain.
Alongside innovative composite materials, we offer all-around solutions for the maintenance and rehabilitation of large-scale works.