P-Trex supports wastewater treatment plant operators in their upgrading and expansion plans with high-performance and functional GFRP structures | P-TREX
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P-Trex supports wastewater treatment plant operators in their upgrading and expansion plans with high-performance and functional GFRP structures

The challenge

Lido di Classe is a seaside resort which constitutes one of the nine tiles that make up the mosaic of Ravenna’s beaches. A major Italian multi-utility has allocated a significant portion of the investments planned for 2021 to the water and energy sectors, including the upgrading of the wastewater treatment plant serving the Lido di Classe area. The purpose of the intervention is to improve the treatment capacity in order to handle the increased quantity of wastewater during the summer period, when the large number of tourists places the plant under pressure. This project also aims to make the facility even more efficient in terms of energy consumption, with direct intervention on some sections of the plant, on pre-treatments and oxidative compartments.
The expertise of P-Trex, a Business Unit of Fibre Net Spa, is inserted in a context where the access structures to the plants and the maintenance activities assume an increasingly important role. The Friuli-based company specializes in the design and production of profiles and structures in GFRP (Glass-Fibre Reinforced Polyester) composite material, which are used in many industrial sectors as an improving alternative to conventional materials. All P-Trex profiles and structures are produced by Fibre Net Spa, a leading company in the market of structural recovery, seismic retrofitting and safety of existing buildings and infrastructures.

The P-TREX Solution

The solutions proposed by the P-Trex team are the result of in-depth analysis and study, and are tailored to the client’s needs, solving the typical criticalities of the context they are involved in. The customer, a well known Italian multi-utility, has provided in the contract specifications the use of GFRP in place of steel for most of the supporting and access structures of the equipment precisely because of its characteristics of durability, light weight, strength and lack of maintenance even in the long term. The P-Trex team fully satisfies the customers’ choice by putting at its disposal the experience of its designers and the quality of a production entirely Made in Italy. The solution overcomes the structural criticalities of geometric and mechanical type, proposing a structural layout extremely functional for access to the equipment and all maintenance operations, without interfering with the equipment itself in compliance with the regulations in force.

The result

All the structures and machinery present in wastewater treatment plants are subject to strong degradation problems because of the constant presence of corrosive substances. In this context, the use of GFRP pultruded profiles and gratings is the best choice because of their intrinsic resistance to corrosion. The profiles and gratings can also be cut, drilled, shaped directly on site, with normal tools without any need for protective treatment of the machined or welded parts, such as cold galvanizing or epoxy coating used in steel processing, solutions known to be not very effective and durable. If required, only for the components most exposed to corrosion, it is possible to seal the cuts by applying a light layer of resin, a very quick and effective operation even in the long term. All this significantly facilitates and speeds up the installation operations, reducing the possibility of error by the assemblers, ensures maximum durability of the structures and reduces maintenance costs.
The large supply, consisting of gangways of various types between 7 and 10m in length, railings, inclined stairs of various shapes complete with intermediate landings and disembarkation, ramps, vertical stairs was scheduled in two tranches and is intended to meet the needs of the entire wastewater treatment system of Lido di Classe, consisting of several sites of plants. To complete the work, covers for tunnels, tanks and sluice gates were also supplied together with grating panels for other types of plant engineering work.
All the structures were pre-assembled in-house and then divided into modules to facilitate transport and handling; delivery times have been planned to coincide with the progress of work on site and in compliance with the activation of the plants.

Benefits of GFRP

The GFRP material is characterized by its lightweight and modularity, which are just two of the main positive benefits of its use, both as a single actor and when combined with traditional materials in a hybrid structure. Because of these benefits, installation is easy, as are time and cost savings. Although large in size, the structure adjacent to the tank was installed in less than a day.
Another significant benefit in the long run, which becomes one of the most important factors from an economic point of view, is that the products boast high resistance to corrosion and do not require maintenance. Compared to traditional materials, it is not necessary to periodically carry out internal/external coatings. Continuous studies and tests have established that the ageing of this material is minimal.
Compared to a structure made entirely of traditional materials such as steel, GFRP products are characterized by their durability over time.

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