StructuralRepairMortar(R4)
High-performance fine-aggregate structural mortar for the repair, jacketing and seismic consolidation of deteriorated reinforced concrete elements.
Cortical repair intervention. The structural mortar reconstitutes the cover concrete expelled by carbonation or rebar oxidation.
The degradation of reinforced concrete (spalling) requires repair work that is not merely cosmetic but restores the element's monolithic integrity and original load-bearing capacity, ensuring mechanical compatibility between old and new.
Standard EN 1504-3 classifies mortars by strength (from R1 to R4). For structural interventions (R3 and R4), it is essential that the mortar's elastic modulus be compatible with that of the existing concrete (typically 20-25 GPa): a mortar that is too rigid or too deformable produces lethal shear stresses at the interface under thermal variations and dynamic loads, causing clean detachment of the repair.
To rebuild edges or the underside of beams without formwork, these mortars are thixotropic: they behave like a fluid under the action of the trowel but freeze their shape instantly at rest. Furthermore, the inclusion of expansive agents counteracts hygrometric shrinkage during setting (compensated shrinkage), eliminating the risk of surface cracking.
Standards
European and international references applicable.
Physical properties
Usage environment
Mandatory substrate preparation: mechanical scarification or hydrodemolition to achieve at least 5 mm surface roughness, followed by water saturation (SSD condition) before application. Without this, even the best mortar will delaminate.
Documented applications
TAV. DCortical repair
Reconstruction of expelled cover concrete on beams, columns and balcony frontals (trowel application).
Structural jacketing
Column jacketing for seismic upgrade or improvement (often pourable).
Structural shotcrete
Mechanical spray projection for massive consolidation of vaults, tunnels or retaining walls.
Anchoring and grouting
Fixing of reinforcement bars, tie rods and metal plates (pourable fluid variants).
Adhesion to Concrete Support (Pull-off test MPa)
TAV. EPull-off test values on sound scarified concrete. For epoxy resins and R4 mortars, failure typically occurs by cohesive rupture within the old concrete — proving the bond is stronger than the substrate itself. The critical parameter is elastic compatibility: mortar elastic modulus must match old concrete (20-25 GPa).
Used in these processes
TAV. PUsed in these systems
TAV. SReference regulations
1 normInformational links to the regulatory framework. Always verify the current text on the official source.
Operational documents from this sheet
Specification clauses, site checklists and compliance dossiers generated from the graph — and kept in sync when a cited norm changes. Join the waiting list.
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