Repair and reinforcement of structure

Descripción sistema

Ferrocarrils de la Generalitat Valenciana (FGV) has more than 26,000 m2 in Torrent in what used to be the old railway workshops, of which approximately 7,000 m2 correspond to buildings such as the depot and the main building. The facilities were designed in its day by the engineer Santiago Castro Cardús and used by the Valencia tram and railway company since 1963, to carry out the maintenance of the rolling stock of the line that linked Valencia with Villanueva de Castellón. When activity began at the current FGV headquarters in Valencia Sud, the Torrent facilities were converted in 1992 into an auxiliary site dedicated to repairs and storage.

Currently, this complex of industrial warehouses, together with its track yard, also serves as a repository for FGV’s collection of historical material. These facilities house more than 70 historic trains and trams from the 19th and 20th centuries, 13 of which have been fully restored.

Among the pieces preserved are the 19th century horse tram, the last one that ran in Valencia before the service was closed in the 1960s, trains such as the Portuguese ones and the Salón Break car. The refurbishment of structures, doors and façades aims to guarantee the conservation of the facilities and all their historic contents.

Reason for the intervention

The refurbishment aims to treat the structure of the facilities as a whole, whether it be of the halls for their conservation, or the water tower, the flagship of the facilities, which was to be conserved as it is visible from miles away and its structure is very deteriorated.

Challenges and constraints

The beams and columns of the tower were carbonated and very deteriorated, the calculation for their restoration and reinforcement was carried out by SEG, a design company with more than 40 years of experience (http://www.seg-sa.es/es/). A covering and enlargement of the cross-section was proposed, for which the use of a fluid repair mortar was deemed necessary. An anti-carbonation coating is also required for the entire HA structure, both for the repaired and unrepaired areas, homogenising, protecting and leaving the same aesthetic finish.

Molins Solution

Remove all deteriorated concrete surface and steel rust by mechanical means or sandblasting, leaving a prepared, resistant and dust-free surface. Carry out the formwork according to the section calculated by the project management, leaving the steel incorporated around the old structure at least 2 cm from the surface of the formwork and at least 1 cm from the inside.

If a protective reinforcement to the pre-existing steel is required, a passivation can be carried out using the product BETOPRIM according to EN 1504-7, corrosion protection of reinforcement against corrosion.

Fill the formwork with PROPAM® REPAR TECHNO FLUID non-shrink R4 repair mortar with a fluid consistency and high adherence without the need for priming in all the areas that can be applied by filling, after the substrate has been well moistened. For repair work where thixotropic non-shrink thixotropic mortar is required use
PROPAM® REPAR TECHNO SR.

Corrosion protection can be increased by spraying CORTEC MC 2021 migratory inhibitor to protect the reinforcement against carbonation and chloride attack.
Finish with BETOPAINT grey anti-carbonation paint as a surface protector leaving a uniform and attractive aesthetic finish.

Execution

The recovery of the facilities was carried out by OBREMO SL as a contracting company with extensive experience in major works. They placed their trust in LEMARA for the reinforcement and recovery of the reinforced concrete, a company highly specialised in this type of work.

The execution was carried out as follows:
“1 . Cleaning, chipping of carbonated and bare concrete of columns of the damaged structures, with cleaning of bare steel both in the tower and in the main hall. A BETOPRIM corrosion passivator was applied to the pre-existing steel.

“The scaffolding is assembled and the steel and formwork is placed in sections for the application of PROPAM® REPAR TECHNO FLUID fluid mortar, starting from the lower part. This is carried out as established with an increase of 7 cm with 12 mm corrugation in the middle of its thickness.

“3. Filling of the formwork with PROPAM® REPAR TECHNO FLUID.

“4. Backfilling is carried out in sections, leaving the column and beam connections for the final formwork, in order to form a monolithic system.

” 5. To protect the reinforced concrete and to leave an aesthetic finish, BETOPAINT grey anti-carbonation paint was applied by roller in accordance with EN 1504-2, a product for surface protection.

Technical note

These works have been carried out taking into account the essential requirements of the EN 1504 standard and the basic requirements of the Technical Building Code (CTE). The repair and rehabilitation of structural elements has to be considered, studied and executed with all the necessary additional controls and elements in order to be able to guarantee that the repaired areas contribute and collaborate again in the structural work.
In a schematic way, we always propose the HA Integral Treatment as a system, which is composed of a number of elements that work together, but which, separately, also meet the technical requirements of their respective standard. These elements are generally shown in the following rendering.