Restoration of a seaside staircase in Liguria near Sori

Regarding the corroded reinforcing bars, we proceeded with the traditional treatment system, cleaning and removing the disintegrated and non-cohesive portions from the bars (also using pressure washers) and then applying SIRIOCEM PF MONO cementitious passivator. This intervention obviously involved various portions within the structure and in a wide variety of application conditions.

The missing sections were reconstructed using SIRIOBETON FA mortar, which proved to be the ideal solution thanks to its characteristics, which offer extremely high adhesion, durability, and waterproofing. This fiber-reinforced, microsilicate-based, shrinkage-resistant mortar is specifically designed for vertical structural repairs.

SIRIOBETON FA is ideal for repairing and remediating concrete cover in aggressive environments or those exposed to frequent freeze-thaw cycles, plastering, and structural consolidation of dams or canal banks, viaducts, or highway and railway bridges. It offers the advantages of quick and easy application on vertical surfaces or ceilings, high mechanical strength, strong and immediate adhesion to the substrate, and the ability to apply thick layers (from 1 to 6 cm), with volumetric stability and excellent durability against chemical attack and the action of water, even under pressure.

For both the steps and the balconies, we chose SIRIOBETON FLEX/M mortar, which offers both effective color and effective protection.

SIRIOBETON FLEX/M is a two-component cementitious compound (with a 3:1 mixing ratio), elastomeric, and waterproof. It is part of the range of products and systems that, when applied, increase the durability of concrete and reinforced concrete structures.

From a classification standpoint, SIRIOBETON FLEX/M complies with UNI EN 1504-2, coating (C) according to the PI, MC, and IR principles (concrete surface protection systems) and UNI EN 1504-9 (products and systems for the protection and repair of concrete structures).

(PI) Principle 1 – Ingress Protection by:

• hydrophobic impregnation;
• impregnation;
• coating

(MC) Principle 2 – Moisture Control:

• hydrophobic impregnation;
• coating

(IR) Principle 8 – Increased Resistivity:

• hydrophobic impregnation;
• coating

The second coat of skim coat can be applied once the surface has hardened (after 3 to 5 hours), and the maximum applicable thickness for a single coat is approximately 2 to 2.5 mm (reinforcement recommended).

To finish the reconstructed structures, RASOCAL mortar was used. This ready-to-use mortar is composed of hydrated mono- and dicalcium silicates, specific wetting agents, controlled-grain aggregates, and additives that promote adhesion and workability.

The complete absence of salts, chemicals, and volatile organic compounds, combined with its entirely mineral composition, guarantees purity, non-toxicity, health safety, and complete recyclability.

The distinctive characteristics of hydraulic lime, such as its slow hardening process and continuous increase in mechanical strength over time, along with a low modulus of elasticity, give the products elasticity, distinguishing them from those made with lime- or cement-based products.

Applied in thin layers (1-2 mm), the mortar does not suffer from rapid water evaporation and offers excellent adhesion to the substrate. Finally, its high level of finish allows it to be left in its natural state or painted with highly breathable paints.

To protect all the reconstructed portions, it was deemed appropriate to apply a non-film-forming water repellent such as HYDROSTOP to the surfaces, which allowed the reconstructed parts to be protected.

HYDROSTOP has the following characteristics:

• a high reaction speed
• blocks cortical crumbling
• good penetration into the substrate being treated
• good permeability to water vapor
• the absence of chromatic variations given the transparent color that does not alter the surfaces
• good durability
• high anti-adhesive power against smog and dust
• the absence of the formation of surface films or sticky surfaces