Repair and protection of the concrete of the training tower of the Zona Franca fire station.

Descripción sistema

The reinforced concrete training tower located in the Zona Franca Fire Station in Barcelona, a few metres from the port, showed degradation of the concrete due to rusting of the reinforcement, with cracks and spalling which left part of the reinforcement exposed.

Reason for the intervention

The tower was in need of structural repair to restore the concrete that had degraded, ensuring the integrity and durability of the structure while restoring its appearance.
Rusting of reinforcement had occurred due to carbonation of the concrete.

Challenges and constraints

“Removal of degraded concrete and the remains of previous repairs and preparation of the substrate.
“Release of reinforcement and protection with BETOPRIM cementitious primer.
“Repair with PROPAM® REPAR TECHNO structural repair mortar.
“Protection of the repaired structure with BETOPAINT anti-carbonation paint.

Execution

“1. Preparation of the substrate:
Removal of all degraded, spalling and cracked concrete by repointing with mechanical means, until the rusted reinforcement was completely exposed. The rust was removed and the reinforcement was cleaned with a steel spike brush.

“2. Reinforcement protection
To ensure the durability of the repair and to protect the reinforcement against corrosion, BETOPRIM cementitious reinforcement protection primer was applied with a short-haired brush in 2 layers, ensuring complete coverage of the entire reinforcement.
“3. Restoration of the removed concrete
For the repair of the tower structure, the structural repair mortar class R4 according to UNE-EN 1504-3, PROPAM® REPAR TECHNO, was chosen.
This repair mortar allows applications of up to 50 mm thick in a single layer and was applied by trowel and trowel after wetting the concrete of the support to saturation.
“Protection of the repaired structure
In order to protect the repaired structure against carbonation and to even out the appearance after the application of the repair mortar, BETOPAINT acrylic anti-carbonation paint was applied with an approximate consumption of 200 g/m2 in 2 coats.

Technical note

Degradation of reinforced concrete by carbonation
_CO2 in the atmosphere (the more polluted it is, the higher the percentage) causes degradation of reinforced concrete. This is called carbonation.
_CO2 penetrates the concrete through its pores, reacts with calcium hydroxide ( Ca(OH₎₂ ) and forms calcium carbonate or limestone (_CaCO3 ).